test: add comprehensive dockerised end-to-end suite

Add a black-box e2e suite (build tag dockere2e) that runs against the
built container image via docker-compose, plus a static nginx mock
upstream for hermetic caching tests.

Coverage:
- repository add/change/delete for remote, local and virtual repos
- caching (miss -> hit + byte integrity) for all 10 remote package types
- local uploads: generic, pypi (with generated simple index), rpm (with
  automatic repodata generation from a real package)
- virtual merges: pypi simple index and helm index.yaml

Driven by scripts/docker-e2e.sh (make docker-e2e): builds the image,
brings the stack up, waits for health, runs the suite, and tears down.
The artifactapi host port is parameterised (ARTIFACTAPI_PORT, default
8000; the e2e run uses 8001). Fixtures are force-tracked over the global
gitignore.

e2e-docker/local_test.go

@@ -0,0 +1,93 @@
+//go:build dockere2e
+
+package e2edocker
+
+import (
+	"bytes"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+)
+
+func uploadFile(t *testing.T, repo, filePath string, body []byte, contentType string) {
+	t.Helper()
+	url := api("/api/v2/remotes/" + repo + "/files/" + filePath)
+	resp, respBody := doRequest(t, http.MethodPut, url, body, contentType)
+	if resp.StatusCode != http.StatusCreated {
+		t.Fatalf("upload %s: status %d: %s", filePath, resp.StatusCode, respBody)
+	}
+}
+
+// TestLocalGenericUpload uploads a generic file and downloads it back.
+func TestLocalGenericUpload(t *testing.T) {
+	createRepo(t, `{"name":"local-generic","package_type":"generic","repo_type":"local"}`)
+	defer deleteRepo(t, "local-generic")
+
+	content := []byte("artifactapi local generic upload payload")
+	uploadFile(t, "local-generic", "data/hello.bin", content, "application/octet-stream")
+
+	resp, body := doRequest(t, http.MethodGet, api("/api/v1/local/local-generic/data/hello.bin"), nil, "")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("download: status %d: %s", resp.StatusCode, body)
+	}
+	if !bytes.Equal(body, content) {
+		t.Fatalf("downloaded content mismatch")
+	}
+}
+
+// TestLocalPyPIUpload uploads a wheel and validates the generated simple index.
+func TestLocalPyPIUpload(t *testing.T) {
+	createRepo(t, `{"name":"local-pypi","package_type":"pypi","repo_type":"local"}`)
+	defer deleteRepo(t, "local-pypi")
+
+	wheel := fixtureBytes(t, "packages/foo-1.0-py3-none-any.whl")
+	uploadFile(t, "local-pypi", "foo-1.0-py3-none-any.whl", wheel, "application/zip")
+
+	// Root index lists the package.
+	resp, body := doRequest(t, http.MethodGet, api("/api/v1/local/local-pypi/simple/"), nil, "")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("simple index: status %d: %s", resp.StatusCode, body)
+	}
+	if !strings.Contains(string(body), "foo") {
+		t.Fatalf("simple index missing package 'foo': %s", body)
+	}
+
+	// Per-package index lists the wheel file.
+	resp, body = doRequest(t, http.MethodGet, api("/api/v1/local/local-pypi/simple/foo/"), nil, "")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("package index: status %d: %s", resp.StatusCode, body)
+	}
+	if !strings.Contains(string(body), "foo-1.0-py3-none-any.whl") {
+		t.Fatalf("package index missing wheel: %s", body)
+	}
+
+	// The wheel downloads back byte-identical.
+	resp, body = doRequest(t, http.MethodGet, api("/api/v1/local/local-pypi/foo/foo-1.0-py3-none-any.whl"), nil, "")
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("download wheel: status %d: %s", resp.StatusCode, body)
+	}
+	if !bytes.Equal(body, wheel) {
+		t.Fatalf("wheel content mismatch")
+	}
+}
+
+// TestLocalRPMRepodata uploads a real RPM and validates that repodata is
+// generated automatically (the special rpm-local feature).
+func TestLocalRPMRepodata(t *testing.T) {
+	createRepo(t, `{"name":"local-rpm","package_type":"rpm","repo_type":"local"}`)
+	defer deleteRepo(t, "local-rpm")
+
+	rpm := fixtureBytes(t, "rpmrepo/Packages/e2e-testpkg-1.0-1.noarch.rpm")
+	uploadFile(t, "local-rpm", "e2e-testpkg-1.0-1.noarch.rpm", rpm, "application/x-rpm")
+
+	// repodata is generated asynchronously after upload; poll for it.
+	resp, body := getEventually(t, api("/api/v1/local/local-rpm/repodata/repomd.xml"), 15*time.Second)
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("repomd.xml: status %d: %s", resp.StatusCode, body)
+	}
+	s := string(body)
+	if !strings.Contains(s, "<repomd") || !strings.Contains(s, "primary") {
+		t.Fatalf("repomd.xml not a valid repodata document: %s", s)
+	}
+}