Evict remote objects from every cache layer

DELETE /objects only removed the artifacts row, so mutable indexes (S3
index object + Redis TTL/ETag keys) kept being served. Clear all layers
and treat a trailing * as a prefix.

internal/proxy/evict_test.go

@@ -0,0 +1,89 @@
+package proxy
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/rpm"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+// changingUpstream serves every path with the current revision, as a mirror
+// does after a sync replaces its repodata.
+func changingUpstream(t *testing.T) (*httptest.Server, *atomic.Value) {
+	t.Helper()
+	var rev atomic.Value
+	rev.Store("rev1")
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		v := rev.Load().(string)
+		w.Header().Set("ETag", `"`+v+`"`)
+		_, _ = w.Write([]byte(v + ":" + r.URL.Path))
+	}))
+	t.Cleanup(srv.Close)
+	return srv, &rev
+}
+
+func fetchBody(t *testing.T, r models.Remote, path string) string {
+	t.Helper()
+	res, err := testEngine.Fetch(context.Background(), r, path, prov(t, models.PackageRPM))
+	if err != nil {
+		t.Fatalf("fetch %s: %v", path, err)
+	}
+	return readAll(t, res)
+}
+
+func rpmRemote(t *testing.T, name, baseURL string) models.Remote {
+	return seed(t, models.Remote{Name: name, PackageType: models.PackageRPM, RepoType: models.RepoTypeRemote, BaseURL: baseURL, MutableTTL: 7200, CheckMutable: true})
+}
+
+func TestEvictMutableIndexRefetches(t *testing.T) {
+	requireStack(t)
+	srv, rev := changingUpstream(t)
+	r := rpmRemote(t, "evict-idx", srv.URL)
+	const path = "8/Everything/x86_64/repodata/repomd.xml"
+
+	if got := fetchBody(t, r, path); got != "rev1:/"+path {
+		t.Fatalf("initial fetch = %q", got)
+	}
+	rev.Store("rev2")
+	if got := fetchBody(t, r, path); got != "rev1:/"+path {
+		t.Fatalf("within TTL = %q, want cached rev1", got)
+	}
+	if err := testEngine.Evict(context.Background(), r.Name, path); err != nil {
+		t.Fatalf("evict: %v", err)
+	}
+	if got := fetchBody(t, r, path); got != "rev2:/"+path {
+		t.Fatalf("after evict = %q, want rev2", got)
+	}
+}
+
+func TestEvictWildcardClearsPrefixOnly(t *testing.T) {
+	requireStack(t)
+	srv, rev := changingUpstream(t)
+	r := rpmRemote(t, "evict-wild", srv.URL)
+	const (
+		repomd = "8/Everything/x86_64/repodata/repomd.xml"
+		rpm    = "8/Everything/x86_64/Packages/a/a-1.0-1.el8.x86_64.rpm"
+		other  = "9/Everything/x86_64/repodata/repomd.xml"
+	)
+	for _, p := range []string{repomd, rpm, other} {
+		fetchBody(t, r, p)
+	}
+	rev.Store("rev2")
+
+	if err := testEngine.Evict(context.Background(), r.Name, "8/Everything/x86_64/*"); err != nil {
+		t.Fatalf("evict: %v", err)
+	}
+	if got := fetchBody(t, r, repomd); got != "rev2:/"+repomd {
+		t.Errorf("index under prefix = %q, want rev2", got)
+	}
+	if got := fetchBody(t, r, rpm); got != "rev2:/"+rpm {
+		t.Errorf("artifact under prefix = %q, want rev2", got)
+	}
+	if got := fetchBody(t, r, other); got != "rev1:/"+other {
+		t.Errorf("path outside prefix = %q, want cached rev1", got)
+	}
+}