diff --git a/api/handlers.go b/api/handlers.go index e7468eefa4..f0258c71d8 100644 --- a/api/handlers.go +++ b/api/handlers.go @@ -27,7 +27,7 @@ func getInfo(c *context, w http.ResponseWriter, r *http.Request) { info := dockerclient.Info{ Containers: int64(len(c.cluster.Containers())), Images: int64(len(c.cluster.Images())), - DriverStatus: c.cluster.Info(), + DriverStatus: c.statusHandler.Status(), NEventsListener: int64(c.eventsHandler.Size()), Debug: c.debug, MemoryLimit: true, diff --git a/api/proxy.go b/api/proxy.go index 3ff86f4ac5..46e0e9e177 100644 --- a/api/proxy.go +++ b/api/proxy.go @@ -2,18 +2,24 @@ package api import ( "crypto/tls" + "fmt" "net/http" + "strings" ) +var localRoutes = []string{"/info", "/_ping"} + // ReverseProxy is a Docker reverse proxy. type ReverseProxy struct { + api http.Handler tlsConfig *tls.Config dest string } // NewReverseProxy creates a new reverse proxy. -func NewReverseProxy(tlsConfig *tls.Config) *ReverseProxy { +func NewReverseProxy(api http.Handler, tlsConfig *tls.Config) *ReverseProxy { return &ReverseProxy{ + api: api, tlsConfig: tlsConfig, } } @@ -26,12 +32,21 @@ func (p *ReverseProxy) SetDestination(dest string) { // ServeHTTP is the http.Handler. func (p *ReverseProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) { + // Check whether we should handle this request locally. + for _, route := range localRoutes { + if strings.HasSuffix(r.URL.Path, route) { + p.api.ServeHTTP(w, r) + return + } + } + + // Otherwise, forward. if p.dest == "" { httpError(w, "No cluster leader", http.StatusInternalServerError) return } if err := hijack(p.tlsConfig, p.dest, w, r); err != nil { - httpError(w, err.Error(), http.StatusInternalServerError) + httpError(w, fmt.Sprintf("Unable to reach cluster leader: %v", err), http.StatusInternalServerError) } } diff --git a/api/router.go b/api/router.go index ece90870e3..4380bd9871 100644 --- a/api/router.go +++ b/api/router.go @@ -13,6 +13,7 @@ import ( type context struct { cluster cluster.Cluster eventsHandler *eventsHandler + statusHandler StatusHandler debug bool tlsConfig *tls.Config } @@ -83,7 +84,7 @@ func writeCorsHeaders(w http.ResponseWriter, r *http.Request) { } // NewRouter creates a new API router. -func NewRouter(cluster cluster.Cluster, tlsConfig *tls.Config, enableCors bool) *mux.Router { +func NewRouter(cluster cluster.Cluster, tlsConfig *tls.Config, status StatusHandler, enableCors bool) *mux.Router { // Register the API events handler in the cluster. eventsHandler := newEventsHandler() cluster.RegisterEventHandler(eventsHandler) @@ -91,6 +92,7 @@ func NewRouter(cluster cluster.Cluster, tlsConfig *tls.Config, enableCors bool) context := &context{ cluster: cluster, eventsHandler: eventsHandler, + statusHandler: status, tlsConfig: tlsConfig, } diff --git a/api/status.go b/api/status.go new file mode 100644 index 0000000000..962e5c9ada --- /dev/null +++ b/api/status.go @@ -0,0 +1,7 @@ +package api + +// StatusHandler allows the API to display extra information on docker info. +type StatusHandler interface { + // Info provides key/values to be added to docker info. + Status() [][]string +} diff --git a/cli/flags.go b/cli/flags.go index 70b7be61ff..bec32bfe1d 100644 --- a/cli/flags.go +++ b/cli/flags.go @@ -119,7 +119,7 @@ var ( } flLeaderElection = cli.BoolFlag{ - Name: "leader-election", - Usage: "Enable cluster leader election between Swarm managers", + Name: "replication", + Usage: "Enable Swarm manager replication", } ) diff --git a/cli/manage.go b/cli/manage.go index 657710e925..b963459aa0 100644 --- a/cli/manage.go +++ b/cli/manage.go @@ -5,7 +5,6 @@ import ( "crypto/x509" "fmt" "io/ioutil" - "net/http" "path" "time" @@ -41,6 +40,30 @@ func (h *logHandler) Handle(e *cluster.Event) error { return nil } +type statusHandler struct { + cluster cluster.Cluster + candidate *leadership.Candidate + follower *leadership.Follower +} + +func (h *statusHandler) Status() [][]string { + var status [][]string + + if h.candidate != nil && !h.candidate.IsLeader() { + status = [][]string{ + {"\bRole", "replica"}, + {"\bPrimary", h.follower.Leader()}, + } + } else { + status = [][]string{ + {"\bRole", "primary"}, + } + } + + status = append(status, h.cluster.Info()...) + return status +} + // Load the TLS certificates/keys and, if verify is true, the CA. func loadTLSConfig(ca, cert, key string, verify bool) (*tls.Config, error) { c, err := tls.LoadX509KeyPair(cert, key) @@ -91,7 +114,7 @@ func createDiscovery(uri string, c *cli.Context) discovery.Discovery { return discovery } -func setupLeaderElection(server *api.Server, apiHandler http.Handler, discovery discovery.Discovery, addr string, tlsConfig *tls.Config) { +func setupReplication(c *cli.Context, cluster cluster.Cluster, server *api.Server, discovery discovery.Discovery, addr string, tlsConfig *tls.Config) { kvDiscovery, ok := discovery.(*kvdiscovery.Discovery) if !ok { log.Fatal("Leader election is only supported with consul, etcd and zookeeper discovery.") @@ -101,7 +124,8 @@ func setupLeaderElection(server *api.Server, apiHandler http.Handler, discovery candidate := leadership.NewCandidate(client, leaderElectionPath, addr) follower := leadership.NewFollower(client, leaderElectionPath) - proxy := api.NewReverseProxy(tlsConfig) + router := api.NewRouter(cluster, tlsConfig, &statusHandler{cluster, candidate, follower}, c.Bool("cors")) + proxy := api.NewReverseProxy(router, tlsConfig) go func() { candidate.RunForElection() @@ -109,7 +133,7 @@ func setupLeaderElection(server *api.Server, apiHandler http.Handler, discovery for isElected := range electedCh { if isElected { log.Info("Cluster leadership acquired") - server.SetHandler(apiHandler) + server.SetHandler(router) } else { log.Info("Cluster leadership lost") server.SetHandler(proxy) @@ -129,6 +153,8 @@ func setupLeaderElection(server *api.Server, apiHandler http.Handler, discovery } } }() + + server.SetHandler(router) } func manage(c *cli.Context) { @@ -208,9 +234,7 @@ func manage(c *cli.Context) { } server := api.NewServer(hosts, tlsConfig) - router := api.NewRouter(cl, tlsConfig, c.Bool("cors")) - - if c.Bool("leader-election") { + if c.Bool("replication") { addr := c.String("advertise") if addr == "" { log.Fatal("--advertise address must be provided when using --leader-election") @@ -219,9 +243,9 @@ func manage(c *cli.Context) { log.Fatal("--advertise should be of the form ip:port or hostname:port") } - setupLeaderElection(server, router, discovery, addr, tlsConfig) + setupReplication(c, cl, server, discovery, addr, tlsConfig) } else { - server.SetHandler(router) + server.SetHandler(api.NewRouter(cl, tlsConfig, &statusHandler{cl, nil, nil}, c.Bool("cors"))) } log.Fatal(server.ListenAndServe())