Add gems remote type for RubyGems (#142)

Ruby builds fetch gems from rubygems.org directly because artifactapi has no RubyGems remote type.

- add `gems` package type proxying `https://rubygems.org`-style sources
- treat `versions`, `names`, `info/*` and `*specs.4.8.gz` as mutable, `gems/*.gem` and `quick/Marshal.4.8/*.gemspec.rz` as immutable
- serve `api/v1/*.json` as `application/json`
- add a gem/bundler usage snippet to the UI and a gems e2e caching case

Requires unkin/artifactapi#148 (HEAD route; RubyGems probes `HEAD /versions`).

Reviewed-on: #142
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

README.md

@@ -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` |
+| `gems` | compact index (`versions`, `info/*`, `names`), `*specs.4.8.gz` | `gems/*.gem`, `quick/Marshal.4.8/*.gemspec.rz` |
 | `nuget` | `index.json` (service index), registration and flat container indexes | `.nupkg`, `.nuspec` |
 | `github_rpm` | `repodata/*` (synthesized) | `.rpm` (redirected) |
 

e2e-docker/README.md

@@ -23,7 +23,7 @@ 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, nuget) proxied through the
+  helm, pypi, npm, rpm, alpine, puppet, terraform, goproxy, cargo, gems, 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/`

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"},
+		{"gems", "gems/mygem-1.0.0.gem", "gems/mygem-1.0.0.gem"},
 		{"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/fixtures/gems/mygem-1.0.0.gem

@@ -0,0 +1 @@
+mygem-1.0.0 e2e fixture

internal/provider/gems/gems.go

@@ -0,0 +1,62 @@
+// Package gems proxies a RubyGems source: mutable compact index (versions,
+// info/*, names) and legacy specs indexes, plus immutable .gem and
+// quick/Marshal.4.8 gemspec downloads.
+package gems
+
+import (
+	"context"
+	"net/http"
+	"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{})
+}
+
+type Provider struct{}
+
+func (p *Provider) Type() models.PackageType { return models.PackageGems }
+
+func (p *Provider) Classify(path string) provider.Mutability {
+	if isGem(path) || isQuickSpec(path) {
+		return provider.Immutable
+	}
+	return provider.Mutable
+}
+
+func (p *Provider) ContentType(path string) string {
+	path = strings.TrimLeft(path, "/")
+	if path == "versions" || path == "names" || strings.HasPrefix(path, "info/") {
+		return "text/plain; charset=utf-8"
+	}
+	if strings.HasPrefix(path, "api/v1/") && strings.HasSuffix(path, ".json") {
+		return "application/json"
+	}
+	return "application/octet-stream"
+}
+
+func (p *Provider) UpstreamURL(remote models.Remote, path string) string {
+	return strings.TrimRight(remote.BaseURL, "/") + "/" + strings.TrimLeft(path, "/")
+}
+
+func (p *Provider) RewriteResponse(_ []byte, _ models.Remote, _ string) ([]byte, error) {
+	return nil, nil
+}
+
+func (p *Provider) AuthHeaders(_ context.Context, remote models.Remote) (http.Header, error) {
+	return auth.BasicHeaders(remote), nil
+}
+
+func isGem(path string) bool {
+	path = strings.TrimLeft(path, "/")
+	return strings.HasPrefix(path, "gems/") && strings.HasSuffix(path, ".gem")
+}
+
+func isQuickSpec(path string) bool {
+	path = strings.TrimLeft(path, "/")
+	return strings.HasPrefix(path, "quick/Marshal.4.8/") && strings.HasSuffix(path, ".gemspec.rz")
+}

internal/provider/gems/gems_test.go

@@ -0,0 +1,61 @@
+package gems
+
+import (
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestClassify(t *testing.T) {
+	p := &Provider{}
+	tests := []struct {
+		path string
+		want provider.Mutability
+	}{
+		{"gems/rack-3.1.8.gem", provider.Immutable},
+		{"/gems/nokogiri-1.16.7-x86_64-linux.gem", provider.Immutable},
+		{"quick/Marshal.4.8/rack-3.1.8.gemspec.rz", provider.Immutable},
+		{"versions", provider.Mutable},
+		{"names", provider.Mutable},
+		{"info/rack", provider.Mutable},
+		{"info/gems", provider.Mutable},
+		{"specs.4.8.gz", provider.Mutable},
+		{"latest_specs.4.8.gz", provider.Mutable},
+		{"prerelease_specs.4.8.gz", provider.Mutable},
+		{"api/v1/dependencies", provider.Mutable},
+		{"quick/Marshal.4.8/", 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 TestContentType(t *testing.T) {
+	p := &Provider{}
+	tests := map[string]string{
+		"versions":                 "text/plain; charset=utf-8",
+		"info/rack":                "text/plain; charset=utf-8",
+		"names":                    "text/plain; charset=utf-8",
+		"gems/rack-3.1.8.gem":      "application/octet-stream",
+		"specs.4.8.gz":             "application/octet-stream",
+		"api/v1/gems/rack.json":    "application/json",
+		"api/v1/dependencies.json": "application/json",
+		"api/v1/dependencies":      "application/octet-stream",
+	}
+	for path, want := range tests {
+		if got := p.ContentType(path); got != want {
+			t.Errorf("ContentType(%q) = %q, want %q", path, got, want)
+		}
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	p := &Provider{}
+	r := models.Remote{BaseURL: "https://rubygems.org/"}
+	if got := p.UpstreamURL(r, "/info/rack"); got != "https://rubygems.org/info/rack" {
+		t.Errorf("UpstreamURL = %q", got)
+	}
+}

internal/server/server.go

@@ -25,6 +25,7 @@ import (
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/cargo"
 	"git.unkin.net/unkin/artifactapi/internal/provider/deb"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/docker"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/gems"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/generic"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/goproxy"
 	_ "git.unkin.net/unkin/artifactapi/internal/provider/helm"

pkg/models/package_type.go

@@ -17,6 +17,7 @@ const (
 	PackageTerraform    PackageType = "terraform"
 	PackageGoProxy      PackageType = "goproxy"
 	PackageCargo        PackageType = "cargo"
+	PackageGems         PackageType = "gems"
 	PackageNuGet        PackageType = "nuget"
 	PackageGitHubRPM    PackageType = "github_rpm"
 	PackageGitHubDeb    PackageType = "github_deb"
@@ -36,6 +37,7 @@ var validPackageTypes = map[PackageType]bool{
 	PackageTerraform:    true,
 	PackageGoProxy:      true,
 	PackageCargo:        true,
+	PackageGems:         true,
 	PackageNuGet:        true,
 	PackageGitHubRPM:    true,
 	PackageGitHubDeb:    true,

pkg/models/package_type_test.go

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

ui/src/components/UsageInstructions.tsx

@@ -243,6 +243,16 @@ index = "sparse+${proxy}/"`,
         },
       ];
 
+    case 'gems':
+      return [
+        {
+          title: 'Use this remote as the RubyGems source',
+          language: 'bash',
+          code: `gem sources --clear-all --add ${proxy}/
+bundle config mirror.https://rubygems.org ${proxy}`,
+        },
+      ];
+
     case 'nuget':
       return [
         {

ui/src/pages/Locals.tsx

@@ -18,6 +18,7 @@ const typeColors: Record<string, 'blue' | 'green' | 'yellow' | 'red' | 'default'
   terraform: 'blue',
   goproxy: 'green',
   cargo: 'yellow',
+  gems: 'red',
   nuget: 'blue',
 };
 

ui/src/pages/Remotes.tsx

@@ -18,6 +18,7 @@ const typeColors: Record<string, 'blue' | 'green' | 'yellow' | 'red' | 'default'
   terraform: 'blue',
   goproxy: 'green',
   cargo: 'yellow',
+  gems: 'red',
   nuget: 'blue',
 };