Files
artifactapi/internal/server/server.go
T
unkinben 109ba2ce27
ci/woodpecker/tag/docker Pipeline was successful
feat: server-level GitHub machine credential for authenticated requests (#109)
## Why

Anonymous GitHub is capped at 60 requests/hour and cannot read private repositories. A machine credential usable by a free (non-enterprise) account is needed to lift the request budget to ~5000/hr and to read private-repo release assets.

Builds on the background syncer (#108, now merged to `master`); this diff is the auth changes only.

## How

- Add `internal/githubauth`: a process-wide GitHub credential delivered via env/secret, applied by default to every outbound GitHub request (releases scan, ranged asset-header GETs, and the generic-github byte proxy for private assets).
- Support two modes:
  - **PAT** — `GITHUB_TOKEN` sent as `Authorization: Bearer <token>`.
  - **GitHub App** — `GITHUB_APP_ID` + `GITHUB_APP_INSTALLATION_ID` + private key (`GITHUB_APP_PRIVATE_KEY` inline PEM or `GITHUB_APP_PRIVATE_KEY_PATH`). Mint a short-lived RS256 JWT with stdlib `crypto/rsa` (no new dependency), exchange it at `POST /app/installations/{id}/access_tokens` for a ~1h installation token, cache it, and single-flight a refresh a few minutes before expiry.
- Inject at the two GitHub call paths: the rpm github provider header builder (releases + ranged fetches) and the generic provider `AuthHeaders` (byte proxy, github.com hosts only; the pre-signed `objects.githubusercontent.com` redirect deliberately gets no Authorization).
- Honor precedence: a remote's own `username`/`password` overrides the server credential; no credential configured stays anonymous (current behavior).
- Fail closed at startup on partial App configuration (e.g. App id without a private key); a token-and-App conflict is also rejected.
- Never persist the credential to the DB, return it from an API, or log it (token-exchange failures never echo the response body).
- Read config via the existing `getenv` convention; document PAT vs App setup, the free-account fine-grained PAT scopes (Contents:read + Metadata:read), precedence, and the rate-limit implication.

## Rate limit

Authenticated requests share the syncer's single global limiter — no second limiter is added. A token raises the effective GitHub ceiling (~5000/hr vs ~60/hr), so the limiter defaults stay safe.

## Tests

`internal/githubauth` and `internal/provider/{rpm,generic}`:
- PAT attaches the correct `Authorization` header to releases + asset-header requests.
- App mints a valid RS256 JWT (verified against the app public key), exchanges it at a mocked endpoint, reuses the cached token without re-exchanging, refreshes near expiry, and single-flights concurrent callers.
- Per-remote credential overrides the server credential (rpm + generic).
- No credential → no `Authorization` header, requests still succeed anonymously.
- ETag/304 flow still works with auth attached.
- The credential does not appear in a remote's serialized JSON.
- Config validation: no-config is anonymous; partial App config and token/App conflict both error.

Verified fail-before/pass-after for the injection tests. `gofmt -l`, `go build ./...`, `go vet ./...`, `go test ./...` all clean (26 packages).

Reviewed-on: #109
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>
2026-08-10 21:42:39 +10:00

265 lines
8.2 KiB
Go

package server
import (
"context"
"errors"
"fmt"
"log/slog"
"net"
"net/http"
"time"
"github.com/go-chi/chi/v5"
"github.com/go-chi/chi/v5/middleware"
tfregistry "git.unkin.net/unkin/artifactapi/internal/api/terraform"
v1 "git.unkin.net/unkin/artifactapi/internal/api/v1"
v2 "git.unkin.net/unkin/artifactapi/internal/api/v2"
"git.unkin.net/unkin/artifactapi/internal/cache"
"git.unkin.net/unkin/artifactapi/internal/config"
"git.unkin.net/unkin/artifactapi/internal/database"
"git.unkin.net/unkin/artifactapi/internal/gc"
"git.unkin.net/unkin/artifactapi/internal/githubauth"
_ "git.unkin.net/unkin/artifactapi/internal/provider/alpine"
_ "git.unkin.net/unkin/artifactapi/internal/provider/docker"
_ "git.unkin.net/unkin/artifactapi/internal/provider/generic"
_ "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/puppet"
_ "git.unkin.net/unkin/artifactapi/internal/provider/pypi"
"git.unkin.net/unkin/artifactapi/internal/provider/rpm"
_ "git.unkin.net/unkin/artifactapi/internal/provider/terraform"
"git.unkin.net/unkin/artifactapi/internal/proxy"
"git.unkin.net/unkin/artifactapi/internal/storage"
"git.unkin.net/unkin/artifactapi/internal/tfsign"
"git.unkin.net/unkin/artifactapi/internal/virtual"
)
type Server struct {
cfg *config.Config
version string
router chi.Router
db *database.DB
cache *cache.Redis
store *storage.S3
engine *proxy.Engine
virtEngine *virtual.Engine
localHandler *v2.LocalHandler
tfRegistry *tfregistry.Handler
gc *gc.Collector
syncer *rpm.Syncer
}
func New(cfg *config.Config, version string) (*Server, error) {
db, err := database.New(cfg.DatabaseDSN())
if err != nil {
return nil, fmt.Errorf("database: %w", err)
}
redis, err := cache.NewRedis(cfg.RedisURL)
if err != nil {
return nil, fmt.Errorf("redis: %w", err)
}
s3, err := storage.NewS3(cfg.S3Endpoint, cfg.S3AccessKey, cfg.S3SecretKey, cfg.S3Bucket, cfg.S3Secure, cfg.S3Region)
if err != nil {
return nil, fmt.Errorf("s3: %w", err)
}
// Install the process-wide GitHub credential before any provider makes an
// outbound call. A misconfiguration (e.g. App id without a private key) fails
// closed here rather than silently falling back to anonymous. No credential
// configured is fine — requests stay anonymous.
ghCred, err := githubauth.New(githubauth.Options{
Token: cfg.GitHubToken,
AppID: cfg.GitHubAppID,
InstallationID: cfg.GitHubAppInstallationID,
PrivateKeyPEM: cfg.GitHubAppPrivateKey,
PrivateKeyPath: cfg.GitHubAppPrivateKeyPath,
})
if err != nil {
return nil, fmt.Errorf("github auth: %w", err)
}
githubauth.SetServer(ghCred)
if ghCred != nil {
slog.Info("github machine credential configured")
}
engine := proxy.NewEngine(db, redis, s3)
localHandler := v2.NewLocalHandler(db, s3)
virtEngine := virtual.NewEngine(db, engine)
collector := gc.New(db, s3, 1*time.Hour)
syncer := rpm.NewSyncer(db, rpm.SyncConfig{
RatePerSec: cfg.GitHubSyncRatePerSec,
Burst: cfg.GitHubSyncBurst,
Workers: cfg.GitHubSyncWorkers,
PollInterval: time.Duration(cfg.GitHubSyncPollInterval) * time.Second,
})
// The terraform registry signs with a GPG key. A configured file wins (BYO
// key); otherwise artifactapi generates one on first start and persists it in
// the database so every replica shares it. A failure here must not take the
// server down — the registry just stays disabled.
var signer *tfsign.Signer
if cfg.TFSigningKeyPath != "" {
signer, err = tfsign.Load(cfg.TFSigningKeyPath, cfg.TFSigningKeyPassphrase)
} else {
signer, err = tfsign.LoadOrCreate(context.Background(), db, "terraform-provider")
}
if err != nil {
slog.Warn("terraform provider registry disabled", "error", err)
signer = nil
}
tfRegistry := tfregistry.NewHandler(db, signer, cfg.TFProviderProtocols)
if tfRegistry.Enabled() {
slog.Info("terraform provider registry enabled", "key_id", signer.KeyID())
}
s := &Server{
cfg: cfg,
version: version,
db: db,
cache: redis,
store: s3,
engine: engine,
virtEngine: virtEngine,
localHandler: localHandler,
tfRegistry: tfRegistry,
gc: collector,
syncer: syncer,
}
s.router = s.routes()
return s, nil
}
func (s *Server) routes() chi.Router {
r := chi.NewRouter()
r.Use(middleware.RequestID)
r.Use(middleware.RealIP)
r.Use(NewStructuredLogger())
r.Use(middleware.Recoverer)
r.Use(cors)
r.Get("/health", s.handleHealth)
r.Get("/", s.handleRoot)
r.Get("/version", s.handleVersion)
// Terraform provider registry: service discovery at the well-known path,
// providers.v1 protocol under /terraform/v1/providers.
r.Get("/.well-known/terraform.json", s.tfRegistry.ServiceDiscovery)
r.Mount(tfregistry.MountPath, s.tfRegistry.Routes())
proxyHandler := v1.NewProxyHandler(s.engine, s.virtEngine, s.db, s.store, s.localHandler)
r.Mount("/api/v1", proxyHandler.Routes())
r.Mount("/v2", proxyHandler.DockerV2Routes())
remotesHandler := v2.NewRemotesHandler(s.db, s.syncer)
virtualsHandler := v2.NewVirtualsHandler(s.db)
healthHandler := v2.NewHealthHandler(s.db, s.cache, s.store)
statsHandler := v2.NewStatsHandler(s.db)
eventsHandler := v2.NewEventsHandler()
probeHandler := v2.NewProbeHandler(s.engine, s.db)
r.Route("/api/v2", func(r chi.Router) {
r.Mount("/remotes", remotesHandler.Routes())
r.Mount("/virtuals", virtualsHandler.Routes())
r.Mount("/health", healthHandler.Routes())
r.Mount("/stats", statsHandler.Routes())
r.Mount("/events", eventsHandler.Routes())
r.Mount("/probe", probeHandler.Routes())
r.Route("/remotes/{name}/objects", func(r chi.Router) {
objHandler := v2.NewObjectsHandler(s.db)
r.Get("/", objHandler.Routes().ServeHTTP)
r.Delete("/*", objHandler.Routes().ServeHTTP)
})
r.Route("/locals/{name}/objects", func(r chi.Router) {
objHandler := v2.NewObjectsHandler(s.db)
r.Get("/", objHandler.LocalRoutes().ServeHTTP)
r.Delete("/*", objHandler.LocalRoutes().ServeHTTP)
})
r.Route("/remotes/{name}/files", func(r chi.Router) {
r.Put("/*", s.localHandler.Routes().ServeHTTP)
r.Get("/*", s.localHandler.Routes().ServeHTTP)
r.Delete("/*", s.localHandler.Routes().ServeHTTP)
})
})
return r
}
func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
fmt.Fprint(w, `{"status":"ok"}`)
}
// handleRoot sends browsers landing on the bare domain to the web UI, which is
// served under /ui. The service identity that used to live here is at /version.
func (s *Server) handleRoot(w http.ResponseWriter, r *http.Request) {
http.Redirect(w, r, "/ui/", http.StatusFound)
}
func (s *Server) handleVersion(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, `{"name":"artifactapi","version":"%s"}`, s.version)
}
func (s *Server) newHTTPServer() *http.Server {
return &http.Server{
Addr: s.cfg.ListenAddr,
Handler: s.router,
ReadTimeout: 30 * time.Second,
WriteTimeout: 300 * time.Second,
IdleTimeout: 120 * time.Second,
}
}
func (s *Server) Run(ctx context.Context) error {
go s.gc.Run(ctx)
go s.syncer.Run(ctx)
httpServer := s.newHTTPServer()
go func() {
<-ctx.Done()
slog.Info("shutting down server")
shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
_ = httpServer.Shutdown(shutdownCtx)
}()
slog.Info("starting server", "addr", s.cfg.ListenAddr)
if err := httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
return err
}
return nil
}
func (s *Server) RunOnListener(ctx context.Context, ln net.Listener) error {
go s.gc.Run(ctx)
go s.syncer.Run(ctx)
httpServer := s.newHTTPServer()
go func() {
<-ctx.Done()
shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
_ = httpServer.Shutdown(shutdownCtx)
}()
slog.Info("starting server", "addr", ln.Addr().String())
if err := httpServer.Serve(ln); err != nil && !errors.Is(err, http.ErrServerClosed) {
return err
}
return nil
}