distribution/registry/registry.go
Manish Tomar 40efb602d6
Add support to gracefully shutdown the server
This is done by draining the connections for configured time after registry receives a SIGTERM signal.
This adds a `draintimeout` setting under `HTTP`. Registry doesn't drain
if draintimeout is not provided.

Signed-off-by: Manish Tomar <manish.tomar@docker.com>
2018-08-20 10:01:26 -07:00

395 lines
11 KiB
Go

package registry
import (
"context"
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
"net/http"
"os"
"os/signal"
"syscall"
"time"
"rsc.io/letsencrypt"
logstash "github.com/bshuster-repo/logrus-logstash-hook"
"github.com/bugsnag/bugsnag-go"
"github.com/docker/distribution/configuration"
dcontext "github.com/docker/distribution/context"
"github.com/docker/distribution/health"
"github.com/docker/distribution/registry/handlers"
"github.com/docker/distribution/registry/listener"
"github.com/docker/distribution/uuid"
"github.com/docker/distribution/version"
"github.com/docker/go-metrics"
gorhandlers "github.com/gorilla/handlers"
log "github.com/sirupsen/logrus"
"github.com/spf13/cobra"
"github.com/yvasiyarov/gorelic"
)
// this channel gets notified when process receives signal. It is global to ease unit testing
var quit = make(chan os.Signal, 1)
// ServeCmd is a cobra command for running the registry.
var ServeCmd = &cobra.Command{
Use: "serve <config>",
Short: "`serve` stores and distributes Docker images",
Long: "`serve` stores and distributes Docker images.",
Run: func(cmd *cobra.Command, args []string) {
// setup context
ctx := dcontext.WithVersion(dcontext.Background(), version.Version)
config, err := resolveConfiguration(args)
if err != nil {
fmt.Fprintf(os.Stderr, "configuration error: %v\n", err)
cmd.Usage()
os.Exit(1)
}
if config.HTTP.Debug.Addr != "" {
go func(addr string) {
log.Infof("debug server listening %v", addr)
if err := http.ListenAndServe(addr, nil); err != nil {
log.Fatalf("error listening on debug interface: %v", err)
}
}(config.HTTP.Debug.Addr)
}
registry, err := NewRegistry(ctx, config)
if err != nil {
log.Fatalln(err)
}
if config.HTTP.Debug.Prometheus.Enabled {
path := config.HTTP.Debug.Prometheus.Path
if path == "" {
path = "/metrics"
}
log.Info("providing prometheus metrics on ", path)
http.Handle(path, metrics.Handler())
}
if err = registry.ListenAndServe(); err != nil {
log.Fatalln(err)
}
},
}
// A Registry represents a complete instance of the registry.
// TODO(aaronl): It might make sense for Registry to become an interface.
type Registry struct {
config *configuration.Configuration
app *handlers.App
server *http.Server
}
// NewRegistry creates a new registry from a context and configuration struct.
func NewRegistry(ctx context.Context, config *configuration.Configuration) (*Registry, error) {
var err error
ctx, err = configureLogging(ctx, config)
if err != nil {
return nil, fmt.Errorf("error configuring logger: %v", err)
}
// inject a logger into the uuid library. warns us if there is a problem
// with uuid generation under low entropy.
uuid.Loggerf = dcontext.GetLogger(ctx).Warnf
app := handlers.NewApp(ctx, config)
// TODO(aaronl): The global scope of the health checks means NewRegistry
// can only be called once per process.
app.RegisterHealthChecks()
handler := configureReporting(app)
handler = alive("/", handler)
handler = health.Handler(handler)
handler = panicHandler(handler)
if !config.Log.AccessLog.Disabled {
handler = gorhandlers.CombinedLoggingHandler(os.Stdout, handler)
}
server := &http.Server{
Handler: handler,
}
return &Registry{
app: app,
config: config,
server: server,
}, nil
}
// ListenAndServe runs the registry's HTTP server.
func (registry *Registry) ListenAndServe() error {
config := registry.config
ln, err := listener.NewListener(config.HTTP.Net, config.HTTP.Addr)
if err != nil {
return err
}
if config.HTTP.TLS.Certificate != "" || config.HTTP.TLS.LetsEncrypt.CacheFile != "" {
tlsConf := &tls.Config{
ClientAuth: tls.NoClientCert,
NextProtos: nextProtos(config),
MinVersion: tls.VersionTLS10,
PreferServerCipherSuites: true,
CipherSuites: []uint16{
tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
},
}
if config.HTTP.TLS.LetsEncrypt.CacheFile != "" {
if config.HTTP.TLS.Certificate != "" {
return fmt.Errorf("cannot specify both certificate and Let's Encrypt")
}
var m letsencrypt.Manager
if err := m.CacheFile(config.HTTP.TLS.LetsEncrypt.CacheFile); err != nil {
return err
}
if !m.Registered() {
if err := m.Register(config.HTTP.TLS.LetsEncrypt.Email, nil); err != nil {
return err
}
}
if len(config.HTTP.TLS.LetsEncrypt.Hosts) > 0 {
m.SetHosts(config.HTTP.TLS.LetsEncrypt.Hosts)
}
tlsConf.GetCertificate = m.GetCertificate
} else {
tlsConf.Certificates = make([]tls.Certificate, 1)
tlsConf.Certificates[0], err = tls.LoadX509KeyPair(config.HTTP.TLS.Certificate, config.HTTP.TLS.Key)
if err != nil {
return err
}
}
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 {
return err
}
if ok := pool.AppendCertsFromPEM(caPem); !ok {
return fmt.Errorf("Could not add CA to pool")
}
}
for _, subj := range pool.Subjects() {
dcontext.GetLogger(registry.app).Debugf("CA Subject: %s", string(subj))
}
tlsConf.ClientAuth = tls.RequireAndVerifyClientCert
tlsConf.ClientCAs = pool
}
ln = tls.NewListener(ln, tlsConf)
dcontext.GetLogger(registry.app).Infof("listening on %v, tls", ln.Addr())
} else {
dcontext.GetLogger(registry.app).Infof("listening on %v", ln.Addr())
}
if config.HTTP.DrainTimeout == 0 {
return registry.server.Serve(ln)
}
// setup channel to get notified on SIGTERM signal
signal.Notify(quit, syscall.SIGTERM)
serveErr := make(chan error)
// Start serving in goroutine and listen for stop signal in main thread
go func() {
serveErr <- registry.server.Serve(ln)
}()
select {
case err := <-serveErr:
return err
case <-quit:
dcontext.GetLogger(registry.app).Info("stopping server gracefully. Draining connections for ", config.HTTP.DrainTimeout)
// shutdown the server with a grace period of configured timeout
c, cancel := context.WithTimeout(context.Background(), config.HTTP.DrainTimeout)
defer cancel()
return registry.server.Shutdown(c)
}
}
func configureReporting(app *handlers.App) http.Handler {
var handler http.Handler = app
if app.Config.Reporting.Bugsnag.APIKey != "" {
bugsnagConfig := bugsnag.Configuration{
APIKey: app.Config.Reporting.Bugsnag.APIKey,
// TODO(brianbland): provide the registry version here
// AppVersion: "2.0",
}
if app.Config.Reporting.Bugsnag.ReleaseStage != "" {
bugsnagConfig.ReleaseStage = app.Config.Reporting.Bugsnag.ReleaseStage
}
if app.Config.Reporting.Bugsnag.Endpoint != "" {
bugsnagConfig.Endpoint = app.Config.Reporting.Bugsnag.Endpoint
}
bugsnag.Configure(bugsnagConfig)
handler = bugsnag.Handler(handler)
}
if app.Config.Reporting.NewRelic.LicenseKey != "" {
agent := gorelic.NewAgent()
agent.NewrelicLicense = app.Config.Reporting.NewRelic.LicenseKey
if app.Config.Reporting.NewRelic.Name != "" {
agent.NewrelicName = app.Config.Reporting.NewRelic.Name
}
agent.CollectHTTPStat = true
agent.Verbose = app.Config.Reporting.NewRelic.Verbose
agent.Run()
handler = agent.WrapHTTPHandler(handler)
}
return handler
}
// 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 = dcontext.WithLogger(ctx, dcontext.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 = dcontext.WithValues(ctx, config.Log.Fields)
ctx = dcontext.WithLogger(ctx, dcontext.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
}
// panicHandler add an 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)
})
}
// 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)
})
}
func resolveConfiguration(args []string) (*configuration.Configuration, error) {
var configurationPath string
if len(args) > 0 {
configurationPath = args[0]
} else if os.Getenv("REGISTRY_CONFIGURATION_PATH") != "" {
configurationPath = os.Getenv("REGISTRY_CONFIGURATION_PATH")
}
if configurationPath == "" {
return nil, fmt.Errorf("configuration path unspecified")
}
fp, err := os.Open(configurationPath)
if err != nil {
return nil, err
}
defer fp.Close()
config, err := configuration.Parse(fp)
if err != nil {
return nil, fmt.Errorf("error parsing %s: %v", configurationPath, err)
}
return config, nil
}
func nextProtos(config *configuration.Configuration) []string {
switch config.HTTP.HTTP2.Disabled {
case true:
return []string{"http/1.1"}
default:
return []string{"h2", "http/1.1"}
}
}