dockerregistry.go

package dockerregistry

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"time"

	log "github.com/Sirupsen/logrus"
	gorillahandlers "github.com/gorilla/handlers"

	"github.com/Sirupsen/logrus/formatters/logstash"
	"github.com/docker/distribution/configuration"
	"github.com/docker/distribution/context"
	"github.com/docker/distribution/health"
	"github.com/docker/distribution/reference"
	"github.com/docker/distribution/registry/auth"
	"github.com/docker/distribution/registry/handlers"
	"github.com/docker/distribution/uuid"
	"github.com/docker/distribution/version"

	_ "github.com/docker/distribution/registry/auth/htpasswd"
	_ "github.com/docker/distribution/registry/auth/token"

	_ "github.com/docker/distribution/registry/proxy"
	_ "github.com/docker/distribution/registry/storage/driver/azure"
	_ "github.com/docker/distribution/registry/storage/driver/filesystem"
	_ "github.com/docker/distribution/registry/storage/driver/gcs"
	_ "github.com/docker/distribution/registry/storage/driver/inmemory"
	_ "github.com/docker/distribution/registry/storage/driver/middleware/cloudfront"
	_ "github.com/docker/distribution/registry/storage/driver/oss"
	_ "github.com/docker/distribution/registry/storage/driver/s3"
	_ "github.com/docker/distribution/registry/storage/driver/swift"

	"github.com/openshift/origin/pkg/cmd/server/crypto"
	"github.com/openshift/origin/pkg/dockerregistry/server"
)

// Execute runs the Docker registry.
func Execute(configFile io.Reader) {
	config, err := configuration.Parse(configFile)
	if err != nil {
		log.Fatalf("Error parsing configuration file: %s", err)
	}

	ctx := context.Background()
	ctx, err = configureLogging(ctx, config)
	if err != nil {
		log.Fatalf("error configuring logger: %v", err)
	}
	log.Infof("version=%s", version.Version)
	// inject a logger into the uuid library. warns us if there is a problem
	// with uuid generation under low entropy.
	uuid.Loggerf = context.GetLogger(ctx).Warnf

	app := handlers.NewApp(ctx, config)

	// TODO add https scheme
	adminRouter := app.NewRoute().PathPrefix("/admin/").Subrouter()

	pruneAccessRecords := func(*http.Request) []auth.Access {
		return []auth.Access{
			{
				Resource: auth.Resource{
					Type: "admin",
				},
				Action: "prune",
			},
		}
	}

	app.RegisterRoute(
		// DELETE /admin/blobs/<digest>
		adminRouter.Path("/blobs/{digest:"+reference.DigestRegexp.String()+"}").Methods("DELETE"),
		// handler
		server.BlobDispatcher,
		// repo name not required in url
		handlers.NameNotRequired,
		// custom access records
		pruneAccessRecords,
	)

	app.RegisterHealthChecks()
	handler := alive("/", app)
	// TODO: temporarily keep for backwards compatibility; remove in the future
	handler = alive("/healthz", handler)
	handler = health.Handler(handler)
	handler = panicHandler(handler)
	handler = gorillahandlers.CombinedLoggingHandler(os.Stdout, handler)

	if config.HTTP.TLS.Certificate == "" {
		context.GetLogger(app).Infof("listening on %v", config.HTTP.Addr)
		if err := http.ListenAndServe(config.HTTP.Addr, handler); err != nil {
			context.GetLogger(app).Fatalln(err)
		}
	} else {
		tlsConf := crypto.SecureTLSConfig(&tls.Config{ClientAuth: tls.NoClientCert})

		if len(config.HTTP.TLS.ClientCAs) != 0 {
			pool := x509.NewCertPool()

			for _, ca := range config.HTTP.TLS.ClientCAs {
				caPem, err := ioutil.ReadFile(ca)
				if err != nil {
					context.GetLogger(app).Fatalln(err)
				}

				if ok := pool.AppendCertsFromPEM(caPem); !ok {
					context.GetLogger(app).Fatalln(fmt.Errorf("Could not add CA to pool"))
				}
			}

			for _, subj := range pool.Subjects() {
				context.GetLogger(app).Debugf("CA Subject: %s", string(subj))
			}

			tlsConf.ClientAuth = tls.RequireAndVerifyClientCert
			tlsConf.ClientCAs = pool
		}

		context.GetLogger(app).Infof("listening on %v, tls", config.HTTP.Addr)
		server := &http.Server{
			Addr:      config.HTTP.Addr,
			Handler:   handler,
			TLSConfig: tlsConf,
		}

		if err := server.ListenAndServeTLS(config.HTTP.TLS.Certificate, config.HTTP.TLS.Key); err != nil {
			context.GetLogger(app).Fatalln(err)
		}
	}
}

// configureLogging prepares the context with a logger using the
// configuration.
func configureLogging(ctx context.Context, config *configuration.Configuration) (context.Context, error) {
	if config.Log.Level == "" && config.Log.Formatter == "" {
		// If no config for logging is set, fallback to deprecated "Loglevel".
		log.SetLevel(logLevel(config.Loglevel))
		ctx = context.WithLogger(ctx, context.GetLogger(ctx))
		return ctx, nil
	}

	log.SetLevel(logLevel(config.Log.Level))

	formatter := config.Log.Formatter
	if formatter == "" {
		formatter = "text" // default formatter
	}

	switch formatter {
	case "json":
		log.SetFormatter(&log.JSONFormatter{
			TimestampFormat: time.RFC3339Nano,
		})
	case "text":
		log.SetFormatter(&log.TextFormatter{
			TimestampFormat: time.RFC3339Nano,
		})
	case "logstash":
		log.SetFormatter(&logstash.LogstashFormatter{
			TimestampFormat: time.RFC3339Nano,
		})
	default:
		// just let the library use default on empty string.
		if config.Log.Formatter != "" {
			return ctx, fmt.Errorf("unsupported logging formatter: %q", config.Log.Formatter)
		}
	}

	if config.Log.Formatter != "" {
		log.Debugf("using %q logging formatter", config.Log.Formatter)
	}

	if len(config.Log.Fields) > 0 {
		// build up the static fields, if present.
		var fields []interface{}
		for k := range config.Log.Fields {
			fields = append(fields, k)
		}

		ctx = context.WithValues(ctx, config.Log.Fields)
		ctx = context.WithLogger(ctx, context.GetLogger(ctx, fields...))
	}

	return ctx, nil
}

func logLevel(level configuration.Loglevel) log.Level {
	l, err := log.ParseLevel(string(level))
	if err != nil {
		l = log.InfoLevel
		log.Warnf("error parsing level %q: %v, using %q	", level, err, l)
	}

	return l
}

// alive simply wraps the handler with a route that always returns an http 200
// response when the path is matched. If the path is not matched, the request
// is passed to the provided handler. There is no guarantee of anything but
// that the server is up. Wrap with other handlers (such as health.Handler)
// for greater affect.
func alive(path string, handler http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == path {
			w.Header().Set("Cache-Control", "no-cache")
			w.WriteHeader(http.StatusOK)
			return
		}

		handler.ServeHTTP(w, r)
	})
}

// panicHandler add a HTTP handler to web app. The handler recover the happening
// panic. logrus.Panic transmits panic message to pre-config log hooks, which is
// defined in config.yml.
func panicHandler(handler http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if err := recover(); err != nil {
				log.Panic(fmt.Sprintf("%v", err))
			}
		}()
		handler.ServeHTTP(w, r)
	})
}