merge master

Puppet modules can only be proxied from a remote Forge; there is nowhere to publish internal modules for puppet module install, r10k and g10k.

- add puppet local uploads at <owner>-<module>-<version>.tar.gz, rejecting existing versions
- record each release's metadata.json, md5 and sha256 in a puppet_metadata table, streaming the tarball under size caps
- serve Forge v3 /v3/modules, paginated /v3/releases, /v3/releases/<slug> and /v3/files
- add an e2e-docker case driving real r10k and puppet module install
- document local puppet in README and UI usage snippets

Reviewed-on: #145
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

README.md

@@ -1,6 +1,6 @@
 # ArtifactAPI
 
-Caching proxy for package repositories. Single Go binary, 11 package types, content-addressable storage, managed by Terraform.
+Caching proxy for package repositories. Single Go binary, 12 package types, content-addressable storage, managed by Terraform.
 
 ## Quick Start
 
@@ -33,6 +33,7 @@ API: `http://localhost:8000` | Frontend: `http://localhost:5173`
 | `terraform` | `*/versions` | `*/download/*/*` |
 | `goproxy` | `@v/list`, `@latest` | `.info`, `.mod`, `.zip` |
 | `cargo` | sparse index files (`config.json` synthesized) | `crates/*/*.crate` |
+| `nuget` | `index.json` (service index), registration and flat container indexes | `.nupkg`, `.nuspec` |
 | `github_rpm` | `repodata/*` (synthesized) | `.rpm` (redirected) |
 
 Providers classify paths automatically. Users only configure what to proxy and TTLs.
@@ -261,6 +262,42 @@ there's nothing to provision. To bring your own key instead, point
 `TF_SIGNING_KEY_PASSPHRASE`), which takes precedence over the generated one.
 `TF_PROVIDER_PROTOCOLS` (default `5.0,6.0`) sets the advertised plugin protocols.
 
+### Local Go module proxy
+
+A local `goproxy` repo serves private modules over the GOPROXY protocol
+(`@v/list`, `@latest`, `@v/<ver>.info|.mod|.zip`). Publish a version by
+uploading its files under the case-encoded module path (uppercase as `!lower`):
+
+```sh
+for ext in zip mod info; do
+  curl -fsSL --upload-file v0.1.0.$ext \
+    https://artifactapi.k8s.syd1.au.unkin.net/api/v2/remotes/go-internal/files/example.unkin.net/hello/@v/v0.1.0.$ext
+done
+GOPROXY=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/go-internal,https://proxy.golang.org,direct \
+GONOSUMDB=example.unkin.net go get example.unkin.net/hello@latest
+```
+
+Build the zip with `golang.org/x/mod/zip` or reuse the files `go mod download`
+leaves in `$(go env GOMODCACHE)/cache/download`. Uploads are validated: zips must
+pass `zip.CheckZip` (every file under `module@version/`), `.mod` must declare the
+module, and `.info` must match the version. `.info` is optional; it is
+synthesized from the version when absent. `@v/list` lists versions with a `.mod`.
+
+### Local puppet forge
+
+A local `puppet` repo is a Forge: `PUT` a module tarball to
+`/api/v2/remotes/<repo>/files/<owner>-<module>-<version>.tar.gz` and the Forge
+v3 API (`/v3/modules`, `/v3/releases`, `/v3/files`) is served from each
+release's `metadata.json` at `/api/v1/local/<repo>`. Versions are immutable.
+
+```bash
+puppet module build ./hello
+curl -fsSL --upload-file pkg/unkin-hello-0.1.0.tar.gz \
+  https://artifactapi.k8s.syd1.au.unkin.net/api/v2/remotes/<repo>/files/unkin-hello-0.1.0.tar.gz
+puppet module install unkin-hello \
+  --module_repository https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/<repo>
+```
+
 ### Local docker registry
 
 A local `docker` repo is a real container registry, not a mirror: it serves the

e2e-docker/README.md

@@ -23,10 +23,11 @@ already-running stack.
 
 - **Repository lifecycle** — add / change / delete for remote, local and virtual repos.
 - **Caching** — one immutable artifact per remote package type (generic, docker,
-  helm, pypi, npm, rpm, alpine, puppet, terraform, goproxy, cargo) proxied through the
+  helm, pypi, npm, rpm, alpine, puppet, terraform, goproxy, cargo, nuget) proxied through the
   mock upstream: first fetch `X-Artifact-Source: remote`, second `cache`, bytes
   verified against the origin fixture.
-- **Local uploads** — generic (upload/download), pypi (wheel + generated `simple/`
+- **Local uploads** — puppet (Forge v3 API via real `r10k` and `puppet module install`),
+  generic (upload/download), pypi (wheel + generated `simple/`
   index), rpm (real package + **automatic repodata** generation).
 - **Virtual repositories** — pypi simple-index merge and helm `index.yaml` merge
   across two members.

e2e-docker/caching_test.go

@@ -30,6 +30,7 @@ func TestCachingPerProvider(t *testing.T) {
 		{"puppet", "puppet-releases/author-mod-1.0.0.tar.gz", "puppet-releases/author-mod-1.0.0.tar.gz"},
 		{"goproxy", "goproxy/example.com/mod/@v/v1.0.0.zip", "goproxy/example.com/mod/@v/v1.0.0.zip"},
 		{"cargo", "crates/mycrate/mycrate-1.0.0.crate", "crates/mycrate/mycrate-1.0.0.crate"},
+		{"nuget", "nuget/e2epkg/1.0.0/e2epkg.1.0.0.nupkg", "nuget/e2epkg/1.0.0/e2epkg.1.0.0.nupkg"},
 		{"terraform", "hashicorp/aws/download/pkg.zip", "v1/providers/hashicorp/aws/download/pkg.zip"},
 		{"docker", "library/testimg/blobs/blobdata", "v2/library/testimg/blobs/blobdata"},
 	}

e2e-docker/goproxy_local_test.go

@@ -0,0 +1,57 @@
+//go:build dockere2e
+
+package e2edocker
+
+import (
+	"bytes"
+	"net/http"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/mod/module"
+	modzip "golang.org/x/mod/zip"
+)
+
+// TestLocalGoProxy publishes two module versions and reads them back over the
+// GOPROXY protocol.
+func TestLocalGoProxy(t *testing.T) {
+	createRepo(t, `{"name":"local-go","package_type":"goproxy","repo_type":"local"}`)
+	defer deleteRepo(t, "local-go")
+
+	const mod = "example.unkin.net/!hello"
+	gomod := []byte("module example.unkin.net/Hello\n\ngo 1.25\n")
+	var zip010 []byte
+	for _, ver := range []string{"v0.1.0", "v0.2.0"} {
+		dir := t.TempDir()
+		os.WriteFile(filepath.Join(dir, "go.mod"), gomod, 0o600)
+		os.WriteFile(filepath.Join(dir, "hello.go"), []byte("package hello\n"), 0o600)
+		var buf bytes.Buffer
+		if err := modzip.CreateFromDir(&buf, module.Version{Path: "example.unkin.net/Hello", Version: ver}, dir); err != nil {
+			t.Fatal(err)
+		}
+		if ver == "v0.1.0" {
+			zip010 = buf.Bytes()
+		}
+		uploadFile(t, "local-go", mod+"/@v/"+ver+".zip", buf.Bytes(), "application/zip")
+		uploadFile(t, "local-go", mod+"/@v/"+ver+".mod", gomod, "text/plain")
+	}
+
+	resp, body := doRequest(t, http.MethodPut, api("/api/v2/remotes/local-go/files/"+mod+"/@v/v0.3.0.zip"), []byte("junk"), "application/zip")
+	if resp.StatusCode != http.StatusBadRequest {
+		t.Fatalf("invalid zip: status %d: %s", resp.StatusCode, body)
+	}
+
+	for path, want := range map[string]string{
+		"/@v/list":        "v0.1.0\nv0.2.0\n",
+		"/@latest":        `{"Version":"v0.2.0"}`,
+		"/@v/v0.1.0.info": `{"Version":"v0.1.0"}`,
+		"/@v/v0.1.0.mod":  string(gomod),
+		"/@v/v0.1.0.zip":  string(zip010),
+	} {
+		resp, body := doRequest(t, http.MethodGet, api("/api/v1/local/local-go/"+mod+path), nil, "")
+		if resp.StatusCode != http.StatusOK || string(body) != want {
+			t.Errorf("%s: status %d body %q", path, resp.StatusCode, body)
+		}
+	}
+}

e2e-docker/puppet_local_test.go

@@ -0,0 +1,88 @@
+//go:build dockere2e
+
+package e2edocker
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"net/http"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+	"time"
+)
+
+const puppetHelloMetadata = `{"name":"unkin-hello","version":"0.1.0","author":"unkin","summary":"e2e","license":"Apache-2.0","source":"https://example.invalid","dependencies":[{"name":"puppetlabs/stdlib","version_requirement":">= 4.0.0 < 10.0.0"}]}`
+
+func puppetModuleTarball(t *testing.T) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	zw := gzip.NewWriter(&buf)
+	tw := tar.NewWriter(zw)
+	for name, body := range map[string]string{
+		"unkin-hello-0.1.0/metadata.json":     puppetHelloMetadata,
+		"unkin-hello-0.1.0/manifests/init.pp": "class hello {}\n",
+	} {
+		if err := tw.WriteHeader(&tar.Header{Name: name, Mode: 0o644, Size: int64(len(body)), ModTime: time.Now()}); err != nil {
+			t.Fatal(err)
+		}
+		_, _ = tw.Write([]byte(body))
+	}
+	_ = tw.Close()
+	_ = zw.Close()
+	return buf.Bytes()
+}
+
+// TestLocalPuppetRealClient publishes a module to a puppet local and installs
+// it with the real r10k and puppet module tool. The stdlib dependency is not on
+// a local-only forge, so puppet runs with --ignore-dependencies.
+func TestLocalPuppetRealClient(t *testing.T) {
+	network := os.Getenv("COMPOSE_NETWORK")
+	internal := strings.TrimRight(os.Getenv("ARTIFACTAPI_INTERNAL"), "/")
+	if network == "" || internal == "" {
+		t.Skip("COMPOSE_NETWORK/ARTIFACTAPI_INTERNAL not set; run via scripts/docker-e2e.sh")
+	}
+	if _, err := exec.LookPath("docker"); err != nil {
+		t.Skip("docker not available on the test host")
+	}
+
+	createRepo(t, `{"name":"local-puppet","package_type":"puppet","repo_type":"local"}`)
+	defer deleteRepo(t, "local-puppet")
+
+	upload := api("/api/v2/remotes/local-puppet/files/unkin-hello-0.1.0.tar.gz")
+	defer doRequest(t, http.MethodDelete, api("/api/v2/remotes/local-puppet/files/v3/files/unkin-hello-0.1.0.tar.gz"), nil, "")
+	tarball := puppetModuleTarball(t)
+	if resp, body := doRequest(t, http.MethodPut, upload, tarball, "application/gzip"); resp.StatusCode != http.StatusCreated {
+		t.Fatalf("upload: %d %s", resp.StatusCode, body)
+	}
+	if resp, _ := doRequest(t, http.MethodPut, upload, tarball, "application/gzip"); resp.StatusCode != http.StatusConflict {
+		t.Fatalf("re-upload of an existing version: %d, want 409", resp.StatusCode)
+	}
+	if resp, body := getEventually(t, api("/api/v1/local/local-puppet/v3/releases/unkin-hello-0.1.0"), 15*time.Second); resp.StatusCode != http.StatusOK || !strings.Contains(string(body), `"file_md5"`) {
+		t.Fatalf("release never indexed: %d %s", resp.StatusCode, body)
+	}
+
+	forge := internal + "/api/v1/local/local-puppet"
+	run := func(image, script string) string {
+		t.Helper()
+		out, err := exec.Command("docker", "run", "--rm", "--network", network, "--entrypoint", "sh", image, "-c", "set -eu; "+script).CombinedOutput()
+		if err != nil {
+			t.Fatalf("%s failed: %v\n%s", image, err, out)
+		}
+		return string(out)
+	}
+
+	out := run("ghcr.io/voxpupuli/r10k:latest", "cd /tmp && printf 'forge:\\n  baseurl: "+forge+"\\n' > r10k.yaml && "+
+		"printf \"forge '"+forge+"'\\nmod 'unkin-hello', '0.1.0'\\n\" > Puppetfile && "+
+		"r10k puppetfile install -c r10k.yaml --verbose && cat modules/hello/metadata.json")
+	if !strings.Contains(out, `"unkin-hello"`) {
+		t.Fatalf("r10k did not install unkin-hello:\n%s", out)
+	}
+
+	out = run("ghcr.io/openvoxproject/openvoxagent:latest", "export PATH=/opt/puppetlabs/bin:$PATH; puppet module install unkin-hello --module_repository "+forge+" --ignore-dependencies --target-dir /tmp/mods && puppet module list --color=false --modulepath /tmp/mods")
+	if !strings.Contains(out, "unkin-hello (v0.1.0)") {
+		t.Fatalf("puppet module install did not install unkin-hello:\n%s", out)
+	}
+}

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/testcontainers/testcontainers-go/modules/redis v0.42.0
 	github.com/ulikunitz/xz v0.5.16
 	golang.org/x/crypto v0.54.0
+	golang.org/x/mod v0.37.0
 	golang.org/x/sync v0.22.0
 	golang.org/x/time v0.15.0
 	gopkg.in/yaml.v3 v3.0.1

go.sum

@@ -227,6 +227,8 @@ golang.org/x/crypto v0.54.0 h1:YLIA59K4fiNzHzjnZt2tUJQjQtUWfWbeHBqKtk3eScw=
 golang.org/x/crypto v0.54.0/go.mod h1:KWL8ny2AZdGR2cWmzeHrp2azQPGogOv+HeQaVEXC2dk=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
+golang.org/x/mod v0.37.0 h1:vF1DjpVEshcIqoEaauuHebaLk1O1forxjxBaVn884JQ=
+golang.org/x/mod v0.37.0/go.mod h1:m8S8VeM9r4dzDwjrKO0a1sZP3YjeMamRRlD+fmR2Q/0=
 golang.org/x/net v0.56.0 h1:Rw8j/hFzGvJUZwNBXnAtf5sVDVt+65SK2C7IxCxZt5o=
 golang.org/x/net v0.56.0/go.mod h1:D3Ku6r+V6JROoZK144D2XfMHFcMq/0zSfLelVTCFKec=
 golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
@@ -247,6 +249,8 @@ golang.org/x/text v0.40.0 h1:Ub2Z6/xjgF1WrYQz2nuITOEegKFtiIy+rieRJ5lHZKs=
 golang.org/x/text v0.40.0/go.mod h1:hpnzDAfGV753zIKo+wk3u1bVKCGPbrnF7+7LBF/UHVY=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
+golang.org/x/tools v0.47.0 h1:7Kn5x/d1svx/PzryTsqeoZN4TZwqeH5pGWjefhLi/1Q=
+golang.org/x/tools v0.47.0/go.mod h1:dFHnyTvFWY212G+h7ZY4Vsp/K3U4/7W9TyVaAul8uCA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

internal/api/v1/proxy.go

@@ -1,6 +1,7 @@
 package v1
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io"
@@ -105,13 +106,24 @@ func (h *ProxyHandler) handleProxy(w http.ResponseWriter, r *http.Request) {
 	}
 	defer result.Reader.Close()
 
+	var body io.Reader = result.Reader
+	if sr, ok := prov.(provider.ServeRewriter); ok && prov.Classify(path) == provider.Mutable {
+		raw, err := io.ReadAll(result.Reader)
+		if err != nil {
+			http.Error(w, "bad gateway", http.StatusBadGateway)
+			return
+		}
+		raw = sr.RewriteServed(raw, *remote, fmt.Sprintf("%s://%s", scheme(r), r.Host))
+		body, result.Size = bytes.NewReader(raw), int64(len(raw))
+	}
+
 	w.Header().Set("Content-Type", result.ContentType)
 	w.Header().Set("X-Artifact-Source", result.Source)
 	if result.Size > 0 {
 		w.Header().Set("X-Artifact-Size", fmt.Sprintf("%d", result.Size))
 	}
 	w.WriteHeader(http.StatusOK)
-	io.Copy(w, result.Reader)
+	io.Copy(w, body)
 }
 
 func (h *ProxyHandler) handleProxyHead(w http.ResponseWriter, r *http.Request) {

internal/api/v2/local.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"os"
 
 	"github.com/go-chi/chi/v5"
 
@@ -83,7 +84,22 @@ func (h *LocalHandler) uploadValidated(w http.ResponseWriter, r *http.Request, r
 		return
 	}
 
-	result, err := h.cas.Store(r.Context(), r.Body, contentType)
+	var body io.Reader = r.Body
+	if cv, ok := prov.(provider.ContentValidator); ok {
+		f, err := spoolBody(r.Body)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("read upload: %v", err), http.StatusInternalServerError)
+			return
+		}
+		defer discard(f)
+		if err := cv.ValidateContent(storagePath, f.Name()); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		body = f
+	}
+
+	result, err := h.cas.Store(r.Context(), body, contentType)
 	if err != nil {
 		http.Error(w, fmt.Sprintf("store failed: %v", err), http.StatusInternalServerError)
 		return
@@ -110,6 +126,27 @@ func (h *LocalHandler) uploadValidated(w http.ResponseWriter, r *http.Request, r
 	writeJSON(w, http.StatusCreated, uploader.UploadResponse(storagePath, result.ContentHash, result.SizeBytes))
 }
 
+func spoolBody(r io.Reader) (*os.File, error) {
+	f, err := os.CreateTemp("", "artifactapi-upload-*")
+	if err != nil {
+		return nil, err
+	}
+	if _, err := io.Copy(f, r); err != nil {
+		discard(f)
+		return nil, err
+	}
+	if _, err := f.Seek(0, io.SeekStart); err != nil {
+		discard(f)
+		return nil, err
+	}
+	return f, nil
+}
+
+func discard(f *os.File) {
+	_ = f.Close()
+	_ = os.Remove(f.Name())
+}
+
 func (h *LocalHandler) uploadGeneric(w http.ResponseWriter, r *http.Request, remote *models.Remote, filePath string) {
 	existing, err := h.db.GetLocalFile(r.Context(), remote.Name, filePath)
 	if err != nil {

internal/api/v2/local_validate_test.go

@@ -0,0 +1,55 @@
+package v2
+
+import (
+	"context"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+
+	"git.unkin.net/unkin/artifactapi/internal/database"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/goproxy"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+// TestLocalUploadContentRejected verifies a ContentValidator provider rejects
+// bad bytes with 400 before anything is stored.
+func TestLocalUploadContentRejected(t *testing.T) {
+	if testDSN == "" {
+		t.Skip("Docker unavailable")
+	}
+	ctx := context.Background()
+	db, err := database.New(testDSN)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	const repo = "go-local-validate"
+	if err := db.CreateRemote(ctx, &models.Remote{Name: repo, PackageType: models.PackageGoProxy, RepoType: models.RepoTypeLocal}); err != nil {
+		t.Fatal(err)
+	}
+
+	router := chi.NewRouter()
+	router.Route("/remotes/{name}/files", func(r chi.Router) {
+		r.Put("/*", NewLocalHandler(db, nil).Routes().ServeHTTP)
+	})
+
+	cases := map[string]string{
+		"example.unkin.net/hello/@v/v0.1.0.zip":  "not a zip",
+		"example.unkin.net/hello/@v/v0.1.0.mod":  "module example.unkin.net/other\n",
+		"example.unkin.net/hello/@v/v0.1.0.info": `{"Version":"v9.9.9"}`,
+		"example.unkin.net/Hello/@v/v0.1.0.mod":  "module example.unkin.net/Hello\n",
+	}
+	for path, body := range cases {
+		w := httptest.NewRecorder()
+		router.ServeHTTP(w, httptest.NewRequest("PUT", "/remotes/"+repo+"/files/"+path, strings.NewReader(body)))
+		if w.Code != 400 {
+			t.Errorf("%s: status %d, want 400 (%s)", path, w.Code, w.Body.String())
+		}
+		if f, _ := db.GetLocalFile(ctx, repo, path); f != nil {
+			t.Errorf("%s: rejected upload was recorded", path)
+		}
+	}
+}

internal/database/puppet_metadata.go

@@ -0,0 +1,46 @@
+package database
+
+import (
+	"context"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+)
+
+func (db *DB) InsertPuppetMetadata(ctx context.Context, meta *provider.PuppetMetadata) error {
+	_, err := db.Pool.Exec(ctx, `
+		INSERT INTO puppet_metadata (repo_name, file_path, content_hash, slug, version, metadata_json, file_size, file_md5)
+		VALUES ($1,$2,$3,$4,$5,$6,$7,$8)
+		ON CONFLICT (repo_name, file_path) DO NOTHING
+	`, meta.RepoName, meta.FilePath, meta.ContentHash, meta.Slug, meta.Version, meta.MetadataJSON, meta.Size, meta.MD5)
+	return err
+}
+
+func (db *DB) DeletePuppetMetadata(ctx context.Context, repoName, filePath string) error {
+	_, err := db.Pool.Exec(ctx, `DELETE FROM puppet_metadata WHERE repo_name = $1 AND file_path = $2`, repoName, filePath)
+	return err
+}
+
+// ListPuppetMetadataEntries returns a repo's releases, optionally narrowed to
+// one module slug (empty slug lists every module).
+func (db *DB) ListPuppetMetadataEntries(ctx context.Context, repoName, slug string) ([]provider.PuppetMetadata, error) {
+	rows, err := db.Pool.Query(ctx, `
+		SELECT repo_name, file_path, content_hash, slug, version, metadata_json, file_size, file_md5, created_at
+		FROM puppet_metadata
+		WHERE repo_name = $1 AND ($2 = '' OR slug = $2)
+		ORDER BY slug, file_path
+	`, repoName, slug)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var result []provider.PuppetMetadata
+	for rows.Next() {
+		var m provider.PuppetMetadata
+		if err := rows.Scan(&m.RepoName, &m.FilePath, &m.ContentHash, &m.Slug, &m.Version, &m.MetadataJSON, &m.Size, &m.MD5, &m.CreatedAt); err != nil {
+			return nil, err
+		}
+		result = append(result, m)
+	}
+	return result, rows.Err()
+}

internal/provider/goproxy/local.go

@@ -0,0 +1,222 @@
+package goproxy
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"slices"
+	"strings"
+
+	"golang.org/x/mod/modfile"
+	"golang.org/x/mod/module"
+	"golang.org/x/mod/semver"
+	modzip "golang.org/x/mod/zip"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+)
+
+type versionFile struct {
+	module  string
+	version string
+	ext     string
+}
+
+// parseVersionFile splits "<escaped module>/@v/<version>.<ext>" into its parts.
+func parseVersionFile(path string) (versionFile, error) {
+	escMod, file, ok := strings.Cut(strings.TrimPrefix(path, "/"), "/@v/")
+	if !ok || escMod == "" || strings.Contains(file, "/") {
+		return versionFile{}, fmt.Errorf("path %q must be <module>/@v/<version>.{zip,mod,info}", path)
+	}
+	dot := strings.LastIndex(file, ".")
+	if dot <= 0 {
+		return versionFile{}, fmt.Errorf("path %q must end in .zip, .mod or .info", path)
+	}
+	ext := file[dot+1:]
+	if ext != "zip" && ext != "mod" && ext != "info" {
+		return versionFile{}, fmt.Errorf("path %q must end in .zip, .mod or .info", path)
+	}
+	mod, err := module.UnescapePath(escMod)
+	if err != nil {
+		return versionFile{}, fmt.Errorf("module path must be case-encoded (uppercase as !lower): %w", err)
+	}
+	ver, err := module.UnescapeVersion(file[:dot])
+	if err != nil {
+		return versionFile{}, err
+	}
+	if err := module.Check(mod, ver); err != nil {
+		return versionFile{}, err
+	}
+	if semver.Canonical(ver) != ver {
+		return versionFile{}, fmt.Errorf("version %q is not canonical semver", ver)
+	}
+	return versionFile{module: mod, version: ver, ext: ext}, nil
+}
+
+func (v versionFile) storagePath() string {
+	escMod, _ := module.EscapePath(v.module)
+	escVer, _ := module.EscapeVersion(v.version)
+	return escMod + "/@v/" + escVer + "." + v.ext
+}
+
+func (p *Provider) ValidateUpload(filePath string) (storagePath, contentType string, err error) {
+	vf, err := parseVersionFile(filePath)
+	if err != nil {
+		return "", "", err
+	}
+	sp := vf.storagePath()
+	return sp, p.ContentType(sp), nil
+}
+
+func (p *Provider) ValidateContent(storagePath, localFile string) error {
+	vf, err := parseVersionFile(storagePath)
+	if err != nil {
+		return err
+	}
+	switch vf.ext {
+	case "zip":
+		if _, err := modzip.CheckZip(module.Version{Path: vf.module, Version: vf.version}, localFile); err != nil {
+			return fmt.Errorf("invalid module zip (files must sit under %s@%s/): %w", vf.module, vf.version, err)
+		}
+	case "mod":
+		data, err := os.ReadFile(localFile)
+		if err != nil {
+			return err
+		}
+		mf, err := modfile.ParseLax("go.mod", data, nil)
+		if err != nil {
+			return fmt.Errorf("invalid go.mod: %w", err)
+		}
+		if mf.Module == nil || mf.Module.Mod.Path != vf.module {
+			return fmt.Errorf("go.mod must declare module %s", vf.module)
+		}
+	case "info":
+		data, err := os.ReadFile(localFile)
+		if err != nil {
+			return err
+		}
+		var info struct{ Version string }
+		if err := json.Unmarshal(data, &info); err != nil {
+			return fmt.Errorf("invalid .info JSON: %w", err)
+		}
+		if info.Version != vf.version {
+			return fmt.Errorf(".info Version %q does not match %s", info.Version, vf.version)
+		}
+	}
+	return nil
+}
+
+func (p *Provider) UploadResponse(storagePath, contentHash string, sizeBytes int64) map[string]any {
+	vf, _ := parseVersionFile(storagePath)
+	return map[string]any{
+		"module":       vf.module,
+		"version":      vf.version,
+		"path":         storagePath,
+		"content_hash": contentHash,
+		"size_bytes":   sizeBytes,
+	}
+}
+
+// versions returns the canonical versions of escMod that have a .mod uploaded, sorted ascending.
+func versions(ctx context.Context, files provider.FileStore, repoName, escMod string) (versions []string, infos map[string]bool, err error) {
+	entries, err := files.ListFilesByPrefix(ctx, repoName, escMod+"/@v/")
+	if err != nil {
+		return nil, nil, err
+	}
+	infos = map[string]bool{}
+	for _, e := range entries {
+		vf, err := parseVersionFile(e.FilePath)
+		if err != nil || vf.storagePath() != e.FilePath {
+			continue
+		}
+		switch vf.ext {
+		case "mod":
+			versions = append(versions, vf.version)
+		case "info":
+			infos[vf.version] = true
+		}
+	}
+	semver.Sort(versions)
+	return versions, infos, nil
+}
+
+func latest(vs []string) string {
+	for i := len(vs) - 1; i >= 0; i-- {
+		if semver.Prerelease(vs[i]) == "" {
+			return vs[i]
+		}
+	}
+	if len(vs) == 0 {
+		return ""
+	}
+	return vs[len(vs)-1]
+}
+
+func infoJSON(version string) []byte {
+	b, _ := json.Marshal(map[string]string{"Version": version})
+	return b
+}
+
+func (p *Provider) ServeLocalIndex(w http.ResponseWriter, r *http.Request, files provider.FileStore, repoName, path string) bool {
+	path = strings.TrimPrefix(path, "/")
+	switch {
+	case strings.HasSuffix(path, "/@v/list"), strings.HasSuffix(path, "/@latest"):
+	case strings.HasSuffix(path, ".info"):
+		vf, err := parseVersionFile(path)
+		if err != nil {
+			return false
+		}
+		escMod, _ := module.EscapePath(vf.module)
+		vs, infos, err := versions(r.Context(), files, repoName, escMod)
+		if err != nil || infos[vf.version] || !slices.Contains(vs, vf.version) {
+			return false
+		}
+	default:
+		return false
+	}
+
+	body, err := p.GenerateLocalIndex(r.Context(), files, repoName, path)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusNotFound)
+		return true
+	}
+	w.Header().Set("Content-Type", p.ContentType(path))
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(body)
+	return true
+}
+
+func (p *Provider) GenerateLocalIndex(ctx context.Context, files provider.FileStore, repoName, path string) ([]byte, error) {
+	path = strings.TrimPrefix(path, "/")
+	if escMod, ok := strings.CutSuffix(path, "/@v/list"); ok {
+		vs, _, err := versions(ctx, files, repoName, escMod)
+		if err != nil {
+			return nil, err
+		}
+		var b strings.Builder
+		for _, v := range vs {
+			b.WriteString(v + "\n")
+		}
+		return []byte(b.String()), nil
+	}
+	if escMod, ok := strings.CutSuffix(path, "/@latest"); ok {
+		vs, _, err := versions(ctx, files, repoName, escMod)
+		if err != nil {
+			return nil, err
+		}
+		v := latest(vs)
+		if v == "" {
+			return nil, fmt.Errorf("no versions of %s", escMod)
+		}
+		return infoJSON(v), nil
+	}
+	if strings.HasSuffix(path, ".info") {
+		vf, err := parseVersionFile(path)
+		if err != nil {
+			return nil, err
+		}
+		return infoJSON(vf.version), nil
+	}
+	return nil, fmt.Errorf("unsupported index path: %q", path)
+}

internal/provider/goproxy/local_test.go

@@ -0,0 +1,198 @@
+package goproxy
+
+import (
+	"archive/zip"
+	"context"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"golang.org/x/mod/module"
+	modzip "golang.org/x/mod/zip"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+)
+
+type fakeFileStore struct{ paths []string }
+
+func (f *fakeFileStore) ListPackages(context.Context, string) ([]string, error) { return nil, nil }
+
+func (f *fakeFileStore) ListFilesByPrefix(_ context.Context, _, prefix string) ([]provider.FileEntry, error) {
+	var out []provider.FileEntry
+	for _, p := range f.paths {
+		if strings.HasPrefix(p, prefix) {
+			out = append(out, provider.FileEntry{FilePath: p, ContentHash: "sha256:x"})
+		}
+	}
+	return out, nil
+}
+
+func TestValidateUpload(t *testing.T) {
+	p := &Provider{}
+	cases := []struct {
+		in, want string
+		ok       bool
+	}{
+		{"example.unkin.net/hello/@v/v0.1.0.zip", "example.unkin.net/hello/@v/v0.1.0.zip", true},
+		{"/example.unkin.net/hello/@v/v0.1.0.mod", "example.unkin.net/hello/@v/v0.1.0.mod", true},
+		{"github.com/!burnt!sushi/toml/@v/v1.2.0.info", "github.com/!burnt!sushi/toml/@v/v1.2.0.info", true},
+		{"example.unkin.net/hello/v2/@v/v2.0.0-rc.1.zip", "example.unkin.net/hello/v2/@v/v2.0.0-rc.1.zip", true},
+		{"github.com/BurntSushi/toml/@v/v1.2.0.zip", "", false},
+		{"example.unkin.net/hello/@v/v0.1.zip", "", false},
+		{"example.unkin.net/hello/@v/v2.0.0.zip", "", false},
+		{"example.unkin.net/hello/@v/v0.1.0.tar.gz", "", false},
+		{"example.unkin.net/hello/v0.1.0.zip", "", false},
+		{"example.unkin.net/hello/@v/list", "", false},
+	}
+	for _, c := range cases {
+		got, ct, err := p.ValidateUpload(c.in)
+		if (err == nil) != c.ok {
+			t.Errorf("%s: err=%v, want ok=%v", c.in, err, c.ok)
+			continue
+		}
+		if c.ok && (got != c.want || ct == "") {
+			t.Errorf("%s: got %q %q, want %q", c.in, got, ct, c.want)
+		}
+	}
+}
+
+func writeZip(t *testing.T, files map[string]string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "m.zip")
+	f, err := os.Create(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	zw := zip.NewWriter(f)
+	for name, body := range files {
+		w, err := zw.Create(name)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := w.Write([]byte(body)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := zw.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return path
+}
+
+func writeFile(t *testing.T, body string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "f")
+	if err := os.WriteFile(path, []byte(body), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	return path
+}
+
+func TestValidateContentZip(t *testing.T) {
+	p := &Provider{}
+	sp := "example.unkin.net/hello/@v/v0.1.0.zip"
+
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module example.unkin.net/hello\n"), 0o600)
+	os.WriteFile(filepath.Join(dir, "main.go"), []byte("package main\n"), 0o600)
+	good := filepath.Join(t.TempDir(), "good.zip")
+	f, _ := os.Create(good)
+	if err := modzip.CreateFromDir(f, module.Version{Path: "example.unkin.net/hello", Version: "v0.1.0"}, dir); err != nil {
+		t.Fatal(err)
+	}
+	f.Close()
+	if err := p.ValidateContent(sp, good); err != nil {
+		t.Errorf("valid zip rejected: %v", err)
+	}
+
+	bad := map[string]map[string]string{
+		"no prefix":     {"go.mod": "module example.unkin.net/hello\n"},
+		"wrong version": {"example.unkin.net/hello@v0.2.0/go.mod": "module example.unkin.net/hello\n"},
+		"wrong module":  {"example.unkin.net/other@v0.1.0/go.mod": "module example.unkin.net/other\n"},
+	}
+	for name, files := range bad {
+		if err := p.ValidateContent(sp, writeZip(t, files)); err == nil {
+			t.Errorf("%s: expected rejection", name)
+		}
+	}
+	if err := p.ValidateContent(sp, writeFile(t, "not a zip")); err == nil {
+		t.Error("non-zip accepted")
+	}
+}
+
+func TestValidateContentModInfo(t *testing.T) {
+	p := &Provider{}
+	mod := "example.unkin.net/hello/@v/v0.1.0.mod"
+	info := "example.unkin.net/hello/@v/v0.1.0.info"
+	cases := []struct {
+		path, body string
+		ok         bool
+	}{
+		{mod, "module example.unkin.net/hello\n\ngo 1.25\n", true},
+		{mod, "module example.unkin.net/other\n", false},
+		{mod, "go 1.25\n", false},
+		{mod, "module (\n", false},
+		{info, `{"Version":"v0.1.0","Time":"2026-01-01T00:00:00Z"}`, true},
+		{info, `{"Version":"v0.2.0"}`, false},
+		{info, `nope`, false},
+	}
+	for _, c := range cases {
+		if err := p.ValidateContent(c.path, writeFile(t, c.body)); (err == nil) != c.ok {
+			t.Errorf("%s %q: err=%v, want ok=%v", c.path, c.body, err, c.ok)
+		}
+	}
+}
+
+func serve(t *testing.T, fs provider.FileStore, path string) (bool, int, string) {
+	t.Helper()
+	rec := httptest.NewRecorder()
+	handled := (&Provider{}).ServeLocalIndex(rec, httptest.NewRequest("GET", "/"+path, nil), fs, "go-local", path)
+	return handled, rec.Code, rec.Body.String()
+}
+
+func TestServeLocalIndex(t *testing.T) {
+	fs := &fakeFileStore{paths: []string{
+		"example.unkin.net/hello/@v/v0.10.0.mod",
+		"example.unkin.net/hello/@v/v0.10.0.zip",
+		"example.unkin.net/hello/@v/v0.2.0.mod",
+		"example.unkin.net/hello/@v/v0.2.0.zip",
+		"example.unkin.net/hello/@v/v0.2.0.info",
+		"example.unkin.net/hello/@v/v0.11.0-rc.1.mod",
+		"example.unkin.net/hello/@v/v0.3.0.zip",
+		"example.unkin.net/hello/v2/@v/v2.0.0.mod",
+		"example.unkin.net/!pre/@v/v1.0.0-beta.mod",
+	}}
+
+	if h, code, body := serve(t, fs, "example.unkin.net/hello/@v/list"); !h || code != 200 || body != "v0.2.0\nv0.10.0\nv0.11.0-rc.1\n" {
+		t.Errorf("list: %v %d %q", h, code, body)
+	}
+	if h, code, body := serve(t, fs, "example.unkin.net/hello/@latest"); !h || code != 200 || body != `{"Version":"v0.10.0"}` {
+		t.Errorf("latest: %v %d %q", h, code, body)
+	}
+	if h, _, body := serve(t, fs, "example.unkin.net/!pre/@latest"); !h || body != `{"Version":"v1.0.0-beta"}` {
+		t.Errorf("prerelease-only latest: %q", body)
+	}
+	if h, code, _ := serve(t, fs, "example.unkin.net/missing/@latest"); !h || code != 404 {
+		t.Errorf("missing latest: %v %d", h, code)
+	}
+	if h, code, body := serve(t, fs, "example.unkin.net/missing/@v/list"); !h || code != 200 || body != "" {
+		t.Errorf("missing list: %v %d %q", h, code, body)
+	}
+	if h, _, body := serve(t, fs, "example.unkin.net/hello/@v/v0.10.0.info"); !h || body != `{"Version":"v0.10.0"}` {
+		t.Errorf("synthesized info: %v %q", h, body)
+	}
+	if h, _, _ := serve(t, fs, "example.unkin.net/hello/@v/v0.2.0.info"); h {
+		t.Error("uploaded .info must be served from storage")
+	}
+	if h, _, _ := serve(t, fs, "example.unkin.net/hello/@v/v0.3.0.info"); h {
+		t.Error(".info without a .mod must not be synthesized")
+	}
+	if h, _, _ := serve(t, fs, "example.unkin.net/hello/@v/v0.10.0.zip"); h {
+		t.Error(".zip must be served from storage")
+	}
+}

internal/provider/nuget/nuget.go

@@ -0,0 +1,85 @@
+// Package nuget proxies a NuGet v3 feed: the service index, registration pages
+// and flat container indexes are mutable, .nupkg/.nuspec downloads immutable.
+package nuget
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"git.unkin.net/unkin/artifactapi/internal/auth"
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func init() {
+	provider.Register(&Provider{})
+}
+
+// serviceIndex is the path clients use as their source URL; it maps to base_url.
+const serviceIndex = "index.json"
+
+type Provider struct{}
+
+func (p *Provider) Type() models.PackageType { return models.PackageNuGet }
+
+func (p *Provider) Classify(path string) provider.Mutability {
+	if isPackage(path) {
+		return provider.Immutable
+	}
+	return provider.Mutable
+}
+
+func (p *Provider) ContentType(path string) string {
+	switch {
+	case strings.HasSuffix(path, ".nupkg"):
+		return "application/octet-stream"
+	case strings.HasSuffix(path, ".nuspec"):
+		return "application/xml"
+	}
+	return "application/json"
+}
+
+// UpstreamURL maps index.json to base_url (the upstream service index) and any
+// other path to the same path on the base_url's origin, where nuget.org serves
+// v3-flatcontainer/ and v3/registration*/.
+func (p *Provider) UpstreamURL(remote models.Remote, path string) string {
+	path = strings.TrimLeft(path, "/")
+	if path == serviceIndex {
+		return remote.BaseURL
+	}
+	return origin(remote.BaseURL) + "/" + path
+}
+
+func (p *Provider) RewriteResponse(_ []byte, _ models.Remote, _ string) ([]byte, error) {
+	return nil, nil
+}
+
+// RewriteServed points upstream-origin URLs in cached JSON back at this remote.
+// It runs per request because the URLs must name the requesting host.
+func (p *Provider) RewriteServed(body []byte, remote models.Remote, proxyBaseURL string) []byte {
+	from := origin(remote.BaseURL)
+	if from == "" || !json.Valid(body) {
+		return body
+	}
+	to := strings.TrimRight(proxyBaseURL, "/") + "/api/v1/remote/" + remote.Name
+	return []byte(strings.ReplaceAll(string(body), from, to))
+}
+
+func (p *Provider) AuthHeaders(_ context.Context, remote models.Remote) (http.Header, error) {
+	return auth.BasicHeaders(remote), nil
+}
+
+func origin(baseURL string) string {
+	u, err := url.Parse(baseURL)
+	if err != nil || u.Host == "" {
+		return ""
+	}
+	return u.Scheme + "://" + u.Host
+}
+
+func isPackage(path string) bool {
+	return strings.HasSuffix(path, ".nupkg") || strings.HasSuffix(path, ".nuspec")
+}

internal/provider/nuget/nuget_test.go

@@ -0,0 +1,68 @@
+package nuget
+
+import (
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+var _ provider.ServeRewriter = (*Provider)(nil)
+
+var nugetOrg = models.Remote{Name: "nuget-org", BaseURL: "https://api.nuget.org/v3/index.json"}
+
+func TestClassify(t *testing.T) {
+	p := &Provider{}
+	tests := []struct {
+		path string
+		want provider.Mutability
+	}{
+		{"v3-flatcontainer/newtonsoft.json/13.0.3/newtonsoft.json.13.0.3.nupkg", provider.Immutable},
+		{"v3-flatcontainer/newtonsoft.json/13.0.3/newtonsoft.json.nuspec", provider.Immutable},
+		{"v3-flatcontainer/newtonsoft.json/index.json", provider.Mutable},
+		{"v3/registration5-gz-semver2/newtonsoft.json/index.json", provider.Mutable},
+		{"index.json", provider.Mutable},
+	}
+	for _, tt := range tests {
+		if got := p.Classify(tt.path); got != tt.want {
+			t.Errorf("Classify(%q) = %v, want %v", tt.path, got, tt.want)
+		}
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	p := &Provider{}
+	tests := []struct {
+		path, want string
+	}{
+		{"index.json", "https://api.nuget.org/v3/index.json"},
+		{"/index.json", "https://api.nuget.org/v3/index.json"},
+		{"v3-flatcontainer/serilog/index.json", "https://api.nuget.org/v3-flatcontainer/serilog/index.json"},
+		{"v3/registration5-gz-semver2/serilog/index.json", "https://api.nuget.org/v3/registration5-gz-semver2/serilog/index.json"},
+	}
+	for _, tt := range tests {
+		if got := p.UpstreamURL(nugetOrg, tt.path); got != tt.want {
+			t.Errorf("UpstreamURL(%q) = %q, want %q", tt.path, got, tt.want)
+		}
+	}
+}
+
+func TestRewriteServed(t *testing.T) {
+	p := &Provider{}
+	body := `{"resources":[` +
+		`{"@id":"https://api.nuget.org/v3-flatcontainer/","@type":"PackageBaseAddress/3.0.0"},` +
+		`{"@id":"https://azuresearch-usnc.nuget.org/query","@type":"SearchQueryService"}]}`
+	want := `{"resources":[` +
+		`{"@id":"http://aa.example:8000/api/v1/remote/nuget-org/v3-flatcontainer/","@type":"PackageBaseAddress/3.0.0"},` +
+		`{"@id":"https://azuresearch-usnc.nuget.org/query","@type":"SearchQueryService"}]}`
+	if got := string(p.RewriteServed([]byte(body), nugetOrg, "http://aa.example:8000/")); got != want {
+		t.Errorf("RewriteServed =\n%s\nwant\n%s", got, want)
+	}
+	if got := string(p.RewriteServed([]byte(body), models.Remote{Name: "x"}, "http://aa.example")); got != body {
+		t.Error("remote without a parseable base_url must pass the body through")
+	}
+	cert := "\x30\x82https://api.nuget.org"
+	if got := string(p.RewriteServed([]byte(cert), nugetOrg, "http://aa.example")); got != cert {
+		t.Error("non-JSON bodies must pass through untouched")
+	}
+}

internal/provider/provider.go

@@ -41,6 +41,11 @@ type LocalUploader interface {
 	UploadResponse(storagePath, contentHash string, sizeBytes int64) map[string]any
 }
 
+// ContentValidator checks an upload's bytes (spooled to localFile) before it is stored.
+type ContentValidator interface {
+	ValidateContent(storagePath, localFile string) error
+}
+
 type LocalIndexer interface {
 	ServeLocalIndex(w http.ResponseWriter, r *http.Request, files FileStore, repoName, path string) bool
 	GenerateLocalIndex(ctx context.Context, files FileStore, repoName, path string) ([]byte, error)
@@ -75,6 +80,13 @@ type RemoteServer interface {
 	ServeRemote(w http.ResponseWriter, r *http.Request, remote models.Remote, path, proxyBaseURL string, store RemoteMetadataStore) bool
 }
 
+// ServeRewriter rewrites a cached mutable remote response per request, for
+// indexes whose URLs must name the requesting host and so cannot be rewritten
+// before caching.
+type ServeRewriter interface {
+	RewriteServed(body []byte, remote models.Remote, proxyBaseURL string) []byte
+}
+
 // RemoteMetadataStore is the persistence surface a RemoteServer needs to cache
 // and read the metadata it derives per upstream asset. *database.DB satisfies it.
 type RemoteMetadataStore interface {
@@ -240,3 +252,29 @@ func Get(t models.PackageType) (Provider, error) {
 func All() map[models.PackageType]Provider {
 	return registry
 }
+
+type PuppetMetadataStore interface {
+	InsertPuppetMetadata(ctx context.Context, meta *PuppetMetadata) error
+}
+
+type PuppetMetadataDeleter interface {
+	DeletePuppetMetadata(ctx context.Context, repoName, filePath string) error
+}
+
+type PuppetMetadataReader interface {
+	ListPuppetMetadataEntries(ctx context.Context, repoName, slug string) ([]PuppetMetadata, error)
+}
+
+// PuppetMetadata is a local module release; MetadataJSON is the tarball's
+// metadata.json verbatim so Forge release objects carry every field.
+type PuppetMetadata struct {
+	RepoName     string
+	FilePath     string
+	ContentHash  string
+	Slug         string
+	Version      string
+	MetadataJSON string
+	Size         int64
+	MD5          string
+	CreatedAt    time.Time
+}

internal/provider/puppet/local.go

@@ -0,0 +1,393 @@
+package puppet
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/url"
+	"path"
+	"regexp"
+	"slices"
+	"strconv"
+	"strings"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/internal/storage"
+)
+
+const filesPrefix = "v3/files/"
+
+// releaseRe matches <owner>-<name>-<semver>, the Forge release slug and the
+// tarball basename that `puppet module build` produces.
+var releaseRe = regexp.MustCompile(`^([a-z0-9]+)-([a-z][a-z0-9_]*)-(\d+\.\d+\.\d+(?:-[0-9a-z.-]+)?(?:\+[0-9a-z.-]+)?)$`)
+
+func parseRelease(s string) (slug, version string, ok bool) {
+	m := releaseRe.FindStringSubmatch(strings.ToLower(s))
+	if m == nil {
+		return "", "", false
+	}
+	return m[1] + "-" + m[2], m[3], true
+}
+
+func normalizeSlug(s string) string {
+	return strings.ToLower(strings.ReplaceAll(s, "/", "-"))
+}
+
+// ValidateUpload stores tarballs under v3/files/ so Forge file_uri downloads
+// resolve straight to the stored file.
+func (p *Provider) ValidateUpload(filePath string) (storagePath, contentType string, err error) {
+	filename := strings.ToLower(path.Base(path.Clean("/" + filePath)))
+	if _, _, ok := parseRelease(strings.TrimSuffix(filename, ".tar.gz")); !ok || !strings.HasSuffix(filename, ".tar.gz") {
+		return "", "", fmt.Errorf("file must be named <owner>-<module>-<version>.tar.gz")
+	}
+	return filesPrefix + filename, "application/gzip", nil
+}
+
+func (p *Provider) UploadResponse(storagePath, contentHash string, sizeBytes int64) map[string]any {
+	return map[string]any{
+		"filename":     path.Base(storagePath),
+		"content_hash": contentHash,
+		"size_bytes":   sizeBytes,
+	}
+}
+
+func (p *Provider) AfterUpload(ctx context.Context, repoName, storagePath, contentHash string, blobs provider.BlobReader, db provider.MetadataStore) {
+	reader, size, err := blobs.Download(ctx, storage.BlobKey(strings.TrimPrefix(contentHash, "sha256:")))
+	if err != nil {
+		slog.Error("puppet metadata: download failed", "repo", repoName, "path", storagePath, "error", err)
+		return
+	}
+	defer func() { _ = reader.Close() }()
+	if size > maxModuleTarball {
+		slog.Error("puppet metadata: tarball too large", "repo", repoName, "path", storagePath, "size", size)
+		return
+	}
+
+	hash := md5.New()
+	src := io.TeeReader(io.LimitReader(reader, maxModuleTarball), hash)
+	meta, err := parseModule(src)
+	if err != nil {
+		slog.Error("puppet metadata: parse failed", "repo", repoName, "path", storagePath, "error", err)
+		return
+	}
+	if _, err := io.Copy(io.Discard, src); err != nil {
+		slog.Error("puppet metadata: read failed", "repo", repoName, "path", storagePath, "error", err)
+		return
+	}
+	slug, version, _ := parseRelease(strings.TrimSuffix(path.Base(storagePath), ".tar.gz"))
+	if meta.Slug != slug || meta.Version != version {
+		slog.Error("puppet metadata: metadata.json does not match filename", "repo", repoName, "path", storagePath, "name", meta.Slug, "version", meta.Version)
+		return
+	}
+	meta.RepoName = repoName
+	meta.FilePath = storagePath
+	meta.ContentHash = contentHash
+	meta.Size = size
+	meta.MD5 = hex.EncodeToString(hash.Sum(nil))
+
+	store, ok := db.(provider.PuppetMetadataStore)
+	if !ok {
+		slog.Error("puppet metadata: store does not support puppet metadata", "repo", repoName)
+		return
+	}
+	if err := store.InsertPuppetMetadata(ctx, meta); err != nil {
+		slog.Error("puppet metadata: insert failed", "repo", repoName, "path", storagePath, "error", err)
+		return
+	}
+	slog.Info("puppet metadata: parsed", "repo", repoName, "module", meta.Slug, "version", meta.Version)
+}
+
+func (p *Provider) AfterDelete(ctx context.Context, repoName, storagePath string, db provider.MetadataDeleter) error {
+	deleter, ok := db.(provider.PuppetMetadataDeleter)
+	if !ok {
+		return nil
+	}
+	return deleter.DeletePuppetMetadata(ctx, repoName, storagePath)
+}
+
+const maxMetadataJSON = 1 << 20
+
+var (
+	maxModuleTarball int64 = 100 << 20
+	maxModuleScan    int64 = 200 << 20
+)
+
+// parseModule reads the top-level <dir>/metadata.json from a module tarball,
+// scanning at most maxModuleScan decompressed bytes.
+func parseModule(r io.Reader) (*provider.PuppetMetadata, error) {
+	zr, err := gzip.NewReader(r)
+	if err != nil {
+		return nil, err
+	}
+	scan := &io.LimitedReader{R: zr, N: maxModuleScan}
+	tr := tar.NewReader(scan)
+	for {
+		hdr, err := tr.Next()
+		if scan.N <= 0 {
+			return nil, errors.New("module tarball exceeds decompressed scan limit before metadata.json")
+		}
+		if err == io.EOF {
+			return nil, errors.New("no metadata.json in module tarball")
+		}
+		if err != nil {
+			return nil, err
+		}
+		dir, file := path.Split(strings.TrimPrefix(path.Clean(hdr.Name), "./"))
+		if hdr.Typeflag != tar.TypeReg || file != "metadata.json" || strings.Count(dir, "/") != 1 {
+			continue
+		}
+		body, err := io.ReadAll(io.LimitReader(tr, maxMetadataJSON))
+		if err != nil {
+			return nil, err
+		}
+		var md struct {
+			Name    string `json:"name"`
+			Version string `json:"version"`
+		}
+		if err := json.Unmarshal(body, &md); err != nil {
+			return nil, fmt.Errorf("parse metadata.json: %w", err)
+		}
+		if md.Name == "" || md.Version == "" {
+			return nil, errors.New("metadata.json missing name or version")
+		}
+		return &provider.PuppetMetadata{Slug: normalizeSlug(md.Name), Version: md.Version, MetadataJSON: string(body)}, nil
+	}
+}
+
+func (p *Provider) ServeLocalIndex(w http.ResponseWriter, r *http.Request, files provider.FileStore, repoName, reqPath string) bool {
+	clean := strings.TrimPrefix(path.Clean("/"+reqPath), "/")
+	var list func(slug string) ([]provider.PuppetMetadata, error)
+	if reader, ok := files.(provider.PuppetMetadataReader); ok {
+		list = func(slug string) ([]provider.PuppetMetadata, error) {
+			metas, err := reader.ListPuppetMetadataEntries(r.Context(), repoName, slug)
+			sortReleases(metas)
+			return metas, err
+		}
+	} else {
+		list = func(string) ([]provider.PuppetMetadata, error) {
+			return nil, errors.New("puppet metadata not available")
+		}
+	}
+
+	switch {
+	case clean == "v3/releases":
+		serveReleaseList(w, r, list)
+	case strings.HasPrefix(clean, "v3/releases/"):
+		slug, version, ok := parseRelease(strings.TrimPrefix(clean, "v3/releases/"))
+		if !ok {
+			notFound(w)
+			return true
+		}
+		metas, err := list(slug)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return true
+		}
+		for _, m := range metas {
+			if m.Version == version {
+				writeJSON(w, releaseObject(m))
+				return true
+			}
+		}
+		notFound(w)
+	case strings.HasPrefix(clean, "v3/modules/"):
+		slug := normalizeSlug(strings.TrimPrefix(clean, "v3/modules/"))
+		metas, err := list(slug)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return true
+		}
+		if len(metas) == 0 {
+			notFound(w)
+			return true
+		}
+		writeJSON(w, moduleObject(metas))
+	default:
+		return false
+	}
+	return true
+}
+
+func (p *Provider) GenerateLocalIndex(ctx context.Context, files provider.FileStore, repoName, path string) ([]byte, error) {
+	return nil, fmt.Errorf("puppet local index generation for virtual repos not supported")
+}
+
+func serveReleaseList(w http.ResponseWriter, r *http.Request, list func(string) ([]provider.PuppetMetadata, error)) {
+	q := r.URL.Query()
+	slug := normalizeSlug(q.Get("module"))
+	limit, err := strconv.Atoi(q.Get("limit"))
+	if err != nil || limit <= 0 {
+		limit = 20
+	}
+	limit = min(limit, 100)
+	offset, err := strconv.Atoi(q.Get("offset"))
+	if err != nil || offset < 0 {
+		offset = 0
+	}
+
+	metas, err := list(slug)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	offset = min(offset, len(metas))
+	results := []map[string]any{}
+	for _, m := range metas[offset : offset+min(limit, len(metas)-offset)] {
+		results = append(results, releaseObject(m))
+	}
+
+	page := func(off int) any {
+		if off < 0 || off >= len(metas) && off != 0 {
+			return nil
+		}
+		v := url.Values{"limit": {strconv.Itoa(limit)}, "offset": {strconv.Itoa(off)}}
+		if slug != "" {
+			v.Set("module", slug)
+		}
+		return "/v3/releases?" + v.Encode()
+	}
+	var previous any
+	if offset > 0 {
+		previous = page(max(offset-limit, 0))
+	}
+	writeJSON(w, map[string]any{
+		"pagination": map[string]any{
+			"limit":    limit,
+			"offset":   offset,
+			"first":    page(0),
+			"previous": previous,
+			"current":  page(offset),
+			"next":     page(offset + limit),
+			"total":    len(metas),
+		},
+		"results": results,
+	})
+}
+
+func owner(slug string) map[string]any {
+	name, _, _ := strings.Cut(slug, "-")
+	return map[string]any{"uri": "/v3/users/" + name, "slug": name, "username": name}
+}
+
+func moduleRef(slug string) map[string]any {
+	_, name, _ := strings.Cut(slug, "-")
+	return map[string]any{"uri": "/v3/modules/" + slug, "slug": slug, "name": name, "deprecated_at": nil, "owner": owner(slug)}
+}
+
+const forgeTime = "2006-01-02 15:04:05 -0700"
+
+func releaseObject(m provider.PuppetMetadata) map[string]any {
+	slug := m.Slug + "-" + m.Version
+	return map[string]any{
+		"uri":         "/v3/releases/" + slug,
+		"slug":        slug,
+		"module":      moduleRef(m.Slug),
+		"version":     m.Version,
+		"metadata":    json.RawMessage(m.MetadataJSON),
+		"tags":        []string{},
+		"supported":   false,
+		"pdk":         false,
+		"file_uri":    "/" + m.FilePath,
+		"file_size":   m.Size,
+		"file_md5":    m.MD5,
+		"file_sha256": strings.TrimPrefix(m.ContentHash, "sha256:"),
+		"downloads":   0,
+		"readme":      nil,
+		"changelog":   nil,
+		"license":     nil,
+		"created_at":  m.CreatedAt.Format(forgeTime),
+		"updated_at":  m.CreatedAt.Format(forgeTime),
+		"deleted_at":  nil,
+	}
+}
+
+// moduleObject expects metas sorted newest version first.
+func moduleObject(metas []provider.PuppetMetadata) map[string]any {
+	obj := moduleRef(metas[0].Slug)
+	releases := make([]map[string]any, 0, len(metas))
+	for _, m := range metas {
+		slug := m.Slug + "-" + m.Version
+		releases = append(releases, map[string]any{
+			"uri": "/v3/releases/" + slug, "slug": slug, "version": m.Version,
+			"file_uri": "/" + m.FilePath, "file_size": m.Size, "supported": false,
+			"created_at": m.CreatedAt.Format(forgeTime), "deleted_at": nil,
+		})
+	}
+	obj["current_release"] = releaseObject(metas[0])
+	obj["releases"] = releases
+	obj["downloads"] = 0
+	obj["created_at"] = metas[len(metas)-1].CreatedAt.Format(forgeTime)
+	obj["updated_at"] = metas[0].CreatedAt.Format(forgeTime)
+	return obj
+}
+
+func writeJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	enc := json.NewEncoder(w)
+	enc.SetEscapeHTML(false)
+	_ = enc.Encode(v)
+}
+
+func notFound(w http.ResponseWriter) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusNotFound)
+	_, _ = io.WriteString(w, `{"message":"404 Not Found","errors":["The requested resource could not be found"]}`)
+}
+
+// sortReleases orders by module slug, then newest semver first.
+func sortReleases(metas []provider.PuppetMetadata) {
+	slices.SortStableFunc(metas, func(a, b provider.PuppetMetadata) int {
+		if c := strings.Compare(a.Slug, b.Slug); c != 0 {
+			return c
+		}
+		return compareSemver(b.Version, a.Version)
+	})
+}
+
+func compareSemver(a, b string) int {
+	a, _, _ = strings.Cut(a, "+")
+	b, _, _ = strings.Cut(b, "+")
+	aCore, aPre, aHasPre := strings.Cut(a, "-")
+	bCore, bPre, bHasPre := strings.Cut(b, "-")
+	if c := compareIdents(strings.Split(aCore, "."), strings.Split(bCore, ".")); c != 0 {
+		return c
+	}
+	switch {
+	case aHasPre && !bHasPre:
+		return -1
+	case !aHasPre && bHasPre:
+		return 1
+	}
+	return compareIdents(strings.Split(aPre, "."), strings.Split(bPre, "."))
+}
+
+func compareIdents(a, b []string) int {
+	for i := 0; i < len(a) && i < len(b); i++ {
+		an, aErr := strconv.Atoi(a[i])
+		bn, bErr := strconv.Atoi(b[i])
+		var c int
+		switch {
+		case aErr == nil && bErr == nil:
+			c = an - bn
+		case aErr == nil:
+			c = -1
+		case bErr == nil:
+			c = 1
+		default:
+			c = strings.Compare(a[i], b[i])
+		}
+		if c != 0 {
+			return c
+		}
+	}
+	return len(a) - len(b)
+}

internal/provider/puppet/local_test.go

@@ -0,0 +1,301 @@
+package puppet
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+)
+
+func moduleTarball(t *testing.T, dir, metadata string) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	zw := gzip.NewWriter(&buf)
+	tw := tar.NewWriter(zw)
+	for name, body := range map[string]string{dir + "/metadata.json": metadata, dir + "/manifests/init.pp": "class hello {}\n"} {
+		if err := tw.WriteHeader(&tar.Header{Name: name, Mode: 0o644, Size: int64(len(body))}); err != nil {
+			t.Fatal(err)
+		}
+		_, _ = tw.Write([]byte(body))
+	}
+	_ = tw.Close()
+	_ = zw.Close()
+	return buf.Bytes()
+}
+
+const helloMetadata = `{"name":"unkin-hello","version":"0.1.0","dependencies":[{"name":"puppetlabs/stdlib","version_requirement":">= 4.0.0"}]}`
+
+type fakeBlobs struct{ data []byte }
+
+func (f fakeBlobs) Download(context.Context, string) (io.ReadCloser, int64, error) {
+	return io.NopCloser(bytes.NewReader(f.data)), int64(len(f.data)), nil
+}
+
+type fakeStore struct{ inserted *provider.PuppetMetadata }
+
+func (f *fakeStore) InsertRPMMetadata(context.Context, *provider.RPMMetadata) error { return nil }
+func (f *fakeStore) InsertDebMetadata(context.Context, *provider.DebMetadata) error { return nil }
+func (f *fakeStore) InsertPuppetMetadata(_ context.Context, m *provider.PuppetMetadata) error {
+	f.inserted = m
+	return nil
+}
+
+type fakeReader struct{ metas []provider.PuppetMetadata }
+
+func (f fakeReader) ListPuppetMetadataEntries(_ context.Context, _, slug string) ([]provider.PuppetMetadata, error) {
+	var out []provider.PuppetMetadata
+	for _, m := range f.metas {
+		if slug == "" || m.Slug == slug {
+			out = append(out, m)
+		}
+	}
+	return out, nil
+}
+func (fakeReader) ListFilesByPrefix(context.Context, string, string) ([]provider.FileEntry, error) {
+	return nil, nil
+}
+func (fakeReader) ListPackages(context.Context, string) ([]string, error) { return nil, nil }
+
+func TestValidateUpload(t *testing.T) {
+	p := &Provider{}
+	sp, ct, err := p.ValidateUpload("some/dir/Unkin-hello-0.1.0.tar.gz")
+	if err != nil || sp != "v3/files/unkin-hello-0.1.0.tar.gz" || ct != "application/gzip" {
+		t.Errorf("sp=%q ct=%q err=%v", sp, ct, err)
+	}
+	for _, bad := range []string{"hello-0.1.0.tar.gz", "unkin-hello-0.1.tar.gz", "unkin-hello-0.1.0.zip", "unkin-Hello_x-0.1.0.tgz"} {
+		if _, _, err := p.ValidateUpload(bad); err == nil {
+			t.Errorf("%q accepted", bad)
+		}
+	}
+}
+
+func TestAfterUploadRecordsMetadata(t *testing.T) {
+	raw := moduleTarball(t, "unkin-hello-0.1.0", helloMetadata)
+	store := &fakeStore{}
+	(&Provider{}).AfterUpload(context.Background(), "forge", "v3/files/unkin-hello-0.1.0.tar.gz", "sha256:abc", fakeBlobs{raw}, store)
+	m := store.inserted
+	if m == nil {
+		t.Fatal("nothing inserted")
+	}
+	sum := md5.Sum(raw)
+	if m.Slug != "unkin-hello" || m.Version != "0.1.0" || m.MD5 != hex.EncodeToString(sum[:]) || m.Size != int64(len(raw)) || m.MetadataJSON != helloMetadata {
+		t.Errorf("got %+v", m)
+	}
+}
+
+func TestAfterUploadRejectsMismatchedFilename(t *testing.T) {
+	raw := moduleTarball(t, "unkin-hello-0.2.0", `{"name":"unkin-hello","version":"0.2.0"}`)
+	store := &fakeStore{}
+	(&Provider{}).AfterUpload(context.Background(), "forge", "v3/files/unkin-hello-0.1.0.tar.gz", "sha256:abc", fakeBlobs{raw}, store)
+	if store.inserted != nil {
+		t.Error("mismatched version indexed")
+	}
+}
+
+func TestParseModuleRequiresTopLevelMetadata(t *testing.T) {
+	if _, err := parseModule(bytes.NewReader(moduleTarball(t, "a/b", helloMetadata))); err == nil {
+		t.Error("nested metadata.json accepted")
+	}
+	if _, err := parseModule(bytes.NewReader(moduleTarball(t, "x", `{"name":"unkin-hello"}`))); err == nil {
+		t.Error("missing version accepted")
+	}
+}
+
+func tarballOf(t *testing.T, entries ...*tar.Header) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	zw := gzip.NewWriter(&buf)
+	tw := tar.NewWriter(zw)
+	for _, h := range entries {
+		if err := tw.WriteHeader(h); err != nil {
+			t.Fatal(err)
+		}
+		if h.Typeflag == tar.TypeReg {
+			body := helloMetadata
+			if !strings.HasSuffix(h.Name, "metadata.json") {
+				body = strings.Repeat("x", int(h.Size))
+			}
+			_, _ = tw.Write([]byte(body))
+		}
+	}
+	_ = tw.Close()
+	_ = zw.Close()
+	return buf.Bytes()
+}
+
+func TestParseModuleSkipsNonRegularMetadata(t *testing.T) {
+	raw := tarballOf(t,
+		&tar.Header{Name: "unkin-hello-0.1.0/metadata.json", Typeflag: tar.TypeSymlink, Linkname: "/etc/passwd"},
+		&tar.Header{Name: "unkin-hello-0.1.0/metadata.json/", Typeflag: tar.TypeDir, Mode: 0o755},
+		&tar.Header{Name: "unkin-hello-0.1.0/metadata.json", Typeflag: tar.TypeReg, Mode: 0o644, Size: int64(len(helloMetadata))},
+	)
+	meta, err := parseModule(bytes.NewReader(raw))
+	if err != nil || meta.Slug != "unkin-hello" || meta.Version != "0.1.0" {
+		t.Fatalf("got %v, %v", meta, err)
+	}
+}
+
+func TestParseModuleCapsDecompressedScan(t *testing.T) {
+	defer func(n int64) { maxModuleScan = n }(maxModuleScan)
+	maxModuleScan = 64 << 10
+	raw := tarballOf(t,
+		&tar.Header{Name: "unkin-hello-0.1.0/big", Typeflag: tar.TypeReg, Mode: 0o644, Size: 1 << 20},
+		&tar.Header{Name: "unkin-hello-0.1.0/metadata.json", Typeflag: tar.TypeReg, Mode: 0o644, Size: int64(len(helloMetadata))},
+	)
+	if _, err := parseModule(bytes.NewReader(raw)); err == nil || !strings.Contains(err.Error(), "scan limit") {
+		t.Fatalf("expected scan limit error, got %v", err)
+	}
+	maxModuleScan = 2 << 20
+	if _, err := parseModule(bytes.NewReader(raw)); err != nil {
+		t.Fatalf("under cap: %v", err)
+	}
+}
+
+func TestAfterUploadCapsTarballSize(t *testing.T) {
+	defer func(n int64) { maxModuleTarball = n }(maxModuleTarball)
+	raw := moduleTarball(t, "unkin-hello-0.1.0", helloMetadata)
+	maxModuleTarball = int64(len(raw)) - 1
+	store := &fakeStore{}
+	(&Provider{}).AfterUpload(context.Background(), "forge", "v3/files/unkin-hello-0.1.0.tar.gz", "sha256:abc", fakeBlobs{raw}, store)
+	if store.inserted != nil {
+		t.Error("oversized tarball indexed")
+	}
+	maxModuleTarball = int64(len(raw))
+	(&Provider{}).AfterUpload(context.Background(), "forge", "v3/files/unkin-hello-0.1.0.tar.gz", "sha256:abc", fakeBlobs{raw}, store)
+	if store.inserted == nil {
+		t.Error("tarball at cap not indexed")
+	}
+}
+
+func TestReleaseListClampsPagination(t *testing.T) {
+	files := releases("0.1.0", "0.2.0", "0.3.0")
+	for _, q := range []string{"offset=9223372036854775807", "offset=9223372036854775807&limit=9223372036854775807", "offset=-5&limit=-5", "limit=9223372036854775807"} {
+		code, body := get(t, files, "v3/releases?module=unkin-hello&"+q)
+		if code != http.StatusOK {
+			t.Fatalf("%s: code %d", q, code)
+		}
+		pg := body["pagination"].(map[string]any)
+		if l := pg["limit"].(float64); l < 1 || l > 100 {
+			t.Errorf("%s: limit %v", q, l)
+		}
+		if o := pg["offset"].(float64); o < 0 || o > 3 {
+			t.Errorf("%s: offset %v", q, o)
+		}
+	}
+	_, body := get(t, files, "v3/releases?module=unkin-hello&offset=9223372036854775807")
+	if len(body["results"].([]any)) != 0 || body["pagination"].(map[string]any)["next"] != nil {
+		t.Errorf("past-end page: %v", body)
+	}
+}
+
+func get(t *testing.T, files provider.FileStore, target string) (int, map[string]any) {
+	t.Helper()
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/x/"+target, nil)
+	path, _, _ := strings.Cut(target, "?")
+	if !(&Provider{}).ServeLocalIndex(rec, req, files, "forge", path) {
+		return 0, nil
+	}
+	var body map[string]any
+	_ = json.Unmarshal(rec.Body.Bytes(), &body)
+	return rec.Code, body
+}
+
+func releases(versions ...string) fakeReader {
+	var f fakeReader
+	for i, v := range versions {
+		f.metas = append(f.metas, provider.PuppetMetadata{
+			FilePath: "v3/files/unkin-hello-" + v + ".tar.gz", ContentHash: "sha256:feed", Slug: "unkin-hello",
+			Version: v, MetadataJSON: `{"name":"unkin-hello","version":"` + v + `"}`, MD5: "m" + v,
+			CreatedAt: time.Unix(int64(i), 0),
+		})
+	}
+	f.metas = append(f.metas, provider.PuppetMetadata{Slug: "other-mod", Version: "9.9.9", MetadataJSON: `{}`})
+	return f
+}
+
+func TestReleaseListPaginatesNewestFirst(t *testing.T) {
+	files := releases("0.1.0", "0.10.0", "0.2.0", "1.0.0-rc.1", "1.0.0")
+	code, body := get(t, files, "v3/releases?module=unkin/hello&limit=2")
+	if code != http.StatusOK {
+		t.Fatalf("code %d", code)
+	}
+	results := body["results"].([]any)
+	pg := body["pagination"].(map[string]any)
+	if len(results) != 2 || results[0].(map[string]any)["version"] != "1.0.0" || results[1].(map[string]any)["version"] != "1.0.0-rc.1" {
+		t.Fatalf("page 1: %v", results)
+	}
+	if pg["total"] != float64(5) || pg["next"] != "/v3/releases?limit=2&module=unkin-hello&offset=2" || pg["previous"] != nil {
+		t.Errorf("pagination: %v", pg)
+	}
+
+	_, body = get(t, files, "v3/releases?module=unkin-hello&limit=2&offset=4")
+	results = body["results"].([]any)
+	pg = body["pagination"].(map[string]any)
+	if len(results) != 1 || results[0].(map[string]any)["version"] != "0.1.0" || pg["next"] != nil || pg["previous"] != "/v3/releases?limit=2&module=unkin-hello&offset=2" {
+		t.Errorf("last page: %v %v", results, pg)
+	}
+
+	_, body = get(t, files, "v3/releases?module=nobody-none")
+	if len(body["results"].([]any)) != 0 {
+		t.Error("unknown module returned results")
+	}
+}
+
+func TestReleaseObject(t *testing.T) {
+	code, body := get(t, releases("0.1.0"), "v3/releases/unkin-hello-0.1.0")
+	if code != http.StatusOK {
+		t.Fatalf("code %d", code)
+	}
+	if body["file_uri"] != "/v3/files/unkin-hello-0.1.0.tar.gz" || body["file_md5"] != "m0.1.0" || body["file_sha256"] != "feed" {
+		t.Errorf("release: %v", body)
+	}
+	if body["metadata"].(map[string]any)["name"] != "unkin-hello" || body["module"].(map[string]any)["owner"].(map[string]any)["username"] != "unkin" {
+		t.Errorf("release refs: %v", body)
+	}
+	if code, _ := get(t, releases("0.1.0"), "v3/releases/unkin-hello-0.2.0"); code != http.StatusNotFound {
+		t.Errorf("missing version: %d", code)
+	}
+}
+
+func TestModuleObject(t *testing.T) {
+	code, body := get(t, releases("0.9.0", "0.10.0"), "v3/modules/unkin-hello")
+	if code != http.StatusOK {
+		t.Fatalf("code %d", code)
+	}
+	if body["slug"] != "unkin-hello" || body["name"] != "hello" || body["current_release"].(map[string]any)["version"] != "0.10.0" || len(body["releases"].([]any)) != 2 {
+		t.Errorf("module: %v", body)
+	}
+	if code, _ := get(t, releases(), "v3/modules/unkin-missing"); code != http.StatusNotFound {
+		t.Errorf("missing module: %d", code)
+	}
+}
+
+func TestFilesFallThrough(t *testing.T) {
+	if code, _ := get(t, releases(), "v3/files/unkin-hello-0.1.0.tar.gz"); code != 0 {
+		t.Error("file downloads must fall through to the stored file")
+	}
+}
+
+func TestCompareSemver(t *testing.T) {
+	ordered := []string{"0.1.0", "0.2.0", "0.10.0", "1.0.0-alpha", "1.0.0-alpha.1", "1.0.0-beta", "1.0.0-beta.2", "1.0.0-beta.11", "1.0.0", "1.0.1+build"}
+	for i := 1; i < len(ordered); i++ {
+		if compareSemver(ordered[i-1], ordered[i]) >= 0 || compareSemver(ordered[i], ordered[i-1]) <= 0 {
+			t.Errorf("%s should sort before %s", ordered[i-1], ordered[i])
+		}
+	}
+	if compareSemver("1.0.0+a", "1.0.0+b") != 0 {
+		t.Error("build metadata must not affect precedence")
+	}
+}

internal/server/server.go

@@ -29,6 +29,7 @@ import (
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/goproxy"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/helm"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/npm"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/nuget"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/puppet"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/pypi"
 	"git.unkin.net/unkin/artifactapi/internal/provider/rpm"

migrations/0004_puppet_metadata.sql

@@ -0,0 +1,15 @@
+CREATE TABLE IF NOT EXISTS puppet_metadata (
+	id            BIGSERIAL PRIMARY KEY,
+	repo_name     TEXT NOT NULL,
+	file_path     TEXT NOT NULL,
+	content_hash  TEXT NOT NULL,
+	slug          TEXT NOT NULL,
+	version       TEXT NOT NULL,
+	metadata_json TEXT NOT NULL,
+	file_size     BIGINT NOT NULL DEFAULT 0,
+	file_md5      TEXT NOT NULL,
+	created_at    TIMESTAMPTZ DEFAULT NOW(),
+	UNIQUE(repo_name, file_path)
+);
+
+CREATE INDEX IF NOT EXISTS idx_puppet_metadata_repo_slug ON puppet_metadata(repo_name, slug);

pkg/models/package_type.go

@@ -17,6 +17,7 @@ const (
 	PackageTerraform    PackageType = "terraform"
 	PackageGoProxy      PackageType = "goproxy"
 	PackageCargo        PackageType = "cargo"
+	PackageNuGet        PackageType = "nuget"
 	PackageGitHubRPM    PackageType = "github_rpm"
 	PackageGitHubDeb    PackageType = "github_deb"
 	PackageGitHubAlpine PackageType = "github_alpine"
@@ -35,6 +36,7 @@ var validPackageTypes = map[PackageType]bool{
 	PackageTerraform:    true,
 	PackageGoProxy:      true,
 	PackageCargo:        true,
+	PackageNuGet:        true,
 	PackageGitHubRPM:    true,
 	PackageGitHubDeb:    true,
 	PackageGitHubAlpine: true,

pkg/models/package_type_test.go

@@ -19,6 +19,7 @@ func TestPackageTypeValid(t *testing.T) {
 		models.PackageTerraform,
 		models.PackageGoProxy,
 		models.PackageCargo,
+		models.PackageNuGet,
 		models.PackageGitHubRPM,
 		models.PackageGitHubDeb,
 		models.PackageGitHubAlpine,

ui/src/components/UsageInstructions.tsx

@@ -218,15 +218,38 @@ sudo apk add --allow-untrusted <package>`,
       ];
 
     case 'goproxy':
-      return [
-        {
-          title: 'Point the Go module proxy here',
-          language: 'bash',
-          code: `export GOPROXY=${proxy}
+      return isLocal
+        ? [
+            {
+              title: 'Fetch private modules from this proxy',
+              language: 'bash',
+              code: `export GOPROXY=${url}/api/v1/local/${name},https://proxy.golang.org,direct
+export GONOSUMDB=example.unkin.net
+go get example.unkin.net/hello@latest`,
+              note: 'Set GONOSUMDB (or GOPRIVATE) to your module prefix: private modules are not in sum.golang.org.',
+            },
+            {
+              title: 'Publish a module version',
+              language: 'bash',
+              code: `# build the zip with golang.org/x/mod/zip (CreateFromDir), or reuse
+# the .zip/.mod/.info from $(go env GOMODCACHE)/cache/download after go mod download
+MOD=example.unkin.net/hello VER=v0.1.0
+for ext in zip mod info; do
+  curl -fsSL --upload-file $VER.$ext \\
+    ${url}/api/v2/remotes/${name}/files/$MOD/@v/$VER.$ext
+done`,
+              note: 'Paths use the case-encoded module path (uppercase as !lower). Zips must hold every file under module@version/ and are rejected otherwise; .info is optional.',
+            },
+          ]
+        : [
+            {
+              title: 'Point the Go module proxy here',
+              language: 'bash',
+              code: `export GOPROXY=${proxy}
 go mod download`,
-          note: 'Append ,direct to fall back to VCS for modules this proxy does not cover.',
-        },
-      ];
+              note: 'Append ,direct to fall back to VCS for modules this proxy does not cover.',
+            },
+          ];
 
     case 'cargo':
       return [
@@ -243,14 +266,40 @@ index = "sparse+${proxy}/"`,
         },
       ];
 
+    case 'nuget':
+      return [
+        {
+          title: 'Use this feed instead of nuget.org',
+          language: 'xml',
+          code: `<!-- nuget.config -->
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="${name}" value="${proxy}/index.json" protocolVersion="3" />
+  </packageSources>
+</configuration>`,
+          note: 'Serve artifactapi over HTTPS: NuGet rejects the repository signatures resource over plain HTTP.',
+        },
+      ];
+
     case 'puppet':
       return [
         {
-          title: 'Install a module from the Forge proxy',
+          title: isLocal ? 'Install a module from this forge' : 'Install a module from the Forge proxy',
           language: 'bash',
           code: `puppet module install <author>-<module> \\
-  --module_repository ${proxy}`,
+  --module_repository ${isLocal ? `${url}/api/v1/local/${name}` : proxy}`,
         },
+        ...(isLocal
+          ? [
+              {
+                title: 'Publish a module (versions are immutable)',
+                language: 'bash',
+                code: `puppet module build && curl -fsSL --upload-file pkg/<author>-<module>-<version>.tar.gz \\
+  ${url}/api/v2/remotes/${name}/files/<author>-<module>-<version>.tar.gz`,
+              },
+            ]
+          : []),
       ];
 
     case 'deb':

ui/src/pages/Locals.tsx

@@ -18,6 +18,7 @@ const typeColors: Record<string, 'blue' | 'green' | 'yellow' | 'red' | 'default'
   terraform: 'blue',
   goproxy: 'green',
   cargo: 'yellow',
+  nuget: 'blue',
 };
 
 export function Locals() {

ui/src/pages/Remotes.tsx

@@ -18,6 +18,7 @@ const typeColors: Record<string, 'blue' | 'green' | 'yellow' | 'red' | 'default'
   terraform: 'blue',
   goproxy: 'green',
   cargo: 'yellow',
+  nuget: 'blue',
 };
 
 export function Remotes() {