From 4d91e791c014d8b85601a241d57d60f37537064c Mon Sep 17 00:00:00 2001 From: Stephen J Day Date: Thu, 9 Apr 2015 18:45:39 -0700 Subject: [PATCH] Disassociate instance id from application This moves the instance id out of the app so that it is associated with an instantiation of the runtime. The instance id is stored on the background context. This allows allow contexts using the main background context to include an instance id for log messages. It also simplifies the application slightly. Signed-off-by: Stephen J Day --- cmd/registry/main.go | 23 +++++++++++------------ context/context.go | 27 +++++++++++++++++++++++++-- registry/handlers/app.go | 28 ++++++---------------------- 3 files changed, 42 insertions(+), 36 deletions(-) diff --git a/cmd/registry/main.go b/cmd/registry/main.go index dc2a53267..7ad59ec69 100644 --- a/cmd/registry/main.go +++ b/cmd/registry/main.go @@ -15,7 +15,7 @@ import ( "github.com/Sirupsen/logrus/formatters/logstash" "github.com/bugsnag/bugsnag-go" "github.com/docker/distribution/configuration" - ctxu "github.com/docker/distribution/context" + "github.com/docker/distribution/context" _ "github.com/docker/distribution/health" _ "github.com/docker/distribution/registry/auth/silly" _ "github.com/docker/distribution/registry/auth/token" @@ -28,7 +28,6 @@ import ( "github.com/docker/distribution/version" gorhandlers "github.com/gorilla/handlers" "github.com/yvasiyarov/gorelic" - "golang.org/x/net/context" ) var showVersion bool @@ -67,9 +66,9 @@ func main() { } if config.HTTP.TLS.Certificate == "" { - ctxu.GetLogger(app).Infof("listening on %v", config.HTTP.Addr) + context.GetLogger(app).Infof("listening on %v", config.HTTP.Addr) if err := http.ListenAndServe(config.HTTP.Addr, handler); err != nil { - ctxu.GetLogger(app).Fatalln(err) + context.GetLogger(app).Fatalln(err) } } else { tlsConf := &tls.Config{ @@ -82,23 +81,23 @@ func main() { for _, ca := range config.HTTP.TLS.ClientCAs { caPem, err := ioutil.ReadFile(ca) if err != nil { - ctxu.GetLogger(app).Fatalln(err) + context.GetLogger(app).Fatalln(err) } if ok := pool.AppendCertsFromPEM(caPem); !ok { - ctxu.GetLogger(app).Fatalln(fmt.Errorf("Could not add CA to pool")) + context.GetLogger(app).Fatalln(fmt.Errorf("Could not add CA to pool")) } } for _, subj := range pool.Subjects() { - ctxu.GetLogger(app).Debugf("CA Subject: %s", string(subj)) + context.GetLogger(app).Debugf("CA Subject: %s", string(subj)) } tlsConf.ClientAuth = tls.RequireAndVerifyClientCert tlsConf.ClientCAs = pool } - ctxu.GetLogger(app).Infof("listening on %v, tls", config.HTTP.Addr) + context.GetLogger(app).Infof("listening on %v, tls", config.HTTP.Addr) server := &http.Server{ Addr: config.HTTP.Addr, Handler: handler, @@ -106,7 +105,7 @@ func main() { } if err := server.ListenAndServeTLS(config.HTTP.TLS.Certificate, config.HTTP.TLS.Key); err != nil { - ctxu.GetLogger(app).Fatalln(err) + context.GetLogger(app).Fatalln(err) } } } @@ -190,7 +189,7 @@ func configureLogging(ctx context.Context, config *configuration.Configuration) if config.Log.Level == "" && config.Log.Formatter == "" { // If no config for logging is set, fallback to deprecated "Loglevel". log.SetLevel(logLevel(config.Loglevel)) - ctx = ctxu.WithLogger(ctx, ctxu.GetLogger(ctx, "version")) + ctx = context.WithLogger(ctx, context.GetLogger(ctx, "version")) return ctx, nil } @@ -224,8 +223,8 @@ func configureLogging(ctx context.Context, config *configuration.Configuration) fields = append(fields, k) } - ctx = ctxu.WithValues(ctx, config.Log.Fields) - ctx = ctxu.WithLogger(ctx, ctxu.GetLogger(ctx, fields...)) + ctx = context.WithValues(ctx, config.Log.Fields) + ctx = context.WithLogger(ctx, context.GetLogger(ctx, fields...)) } return ctx, nil diff --git a/context/context.go b/context/context.go index 296d9ac38..45a35ad17 100644 --- a/context/context.go +++ b/context/context.go @@ -1,6 +1,7 @@ package context import ( + "code.google.com/p/go-uuid/uuid" "golang.org/x/net/context" ) @@ -9,9 +10,31 @@ type Context interface { context.Context } -// Background returns a non-nil, empty Context. +// instanceContext is a context that provides only an instance id. It is +// provided as the main background context. +type instanceContext struct { + Context + id string // id of context, logged as "instance.id" +} + +func (ic *instanceContext) Value(key interface{}) interface{} { + if key == "instance.id" { + return ic.id + } + + return ic.Context.Value(key) +} + +var background = &instanceContext{ + Context: context.Background(), + id: uuid.New(), +} + +// Background returns a non-nil, empty Context. The background context +// provides a single key, "instance.id" that is globally unique to the +// process. func Background() Context { - return context.Background() + return background } // WithValue returns a copy of parent in which the value associated with key is diff --git a/registry/handlers/app.go b/registry/handlers/app.go index fac93382f..059af260f 100644 --- a/registry/handlers/app.go +++ b/registry/handlers/app.go @@ -8,7 +8,6 @@ import ( "os" "time" - "code.google.com/p/go-uuid/uuid" "github.com/docker/distribution" "github.com/docker/distribution/configuration" ctxu "github.com/docker/distribution/context" @@ -32,11 +31,8 @@ import ( // fields should be protected. type App struct { context.Context - Config configuration.Configuration - // InstanceID is a unique id assigned to the application on each creation. - // Provides information in the logs and context to identify restarts. - InstanceID string + Config configuration.Configuration router *mux.Router // main application router, configured with dispatchers driver storagedriver.StorageDriver // driver maintains the app global storage driver instance. @@ -52,29 +48,17 @@ type App struct { redis *redis.Pool } -// Value intercepts calls context.Context.Value, returning the current app id, -// if requested. -func (app *App) Value(key interface{}) interface{} { - switch key { - case "app.id": - return app.InstanceID - } - - return app.Context.Value(key) -} - // NewApp takes a configuration and returns a configured app, ready to serve // requests. The app only implements ServeHTTP and can be wrapped in other // handlers accordingly. func NewApp(ctx context.Context, configuration configuration.Configuration) *App { app := &App{ - Config: configuration, - Context: ctx, - InstanceID: uuid.New(), - router: v2.RouterWithPrefix(configuration.HTTP.Prefix), + Config: configuration, + Context: ctx, + router: v2.RouterWithPrefix(configuration.HTTP.Prefix), } - app.Context = ctxu.WithLogger(app.Context, ctxu.GetLogger(app, "app.id")) + app.Context = ctxu.WithLogger(app.Context, ctxu.GetLogger(app, "instance.id")) // Register the handler dispatchers. app.register(v2.RouteNameBase, func(ctx *Context, r *http.Request) http.Handler { @@ -200,7 +184,7 @@ func (app *App) configureEvents(configuration *configuration.Configuration) { app.events.source = notifications.SourceRecord{ Addr: hostname, - InstanceID: app.InstanceID, + InstanceID: ctxu.GetStringValue(app, "instance.id"), } }