Merge pull request #310 from rqlite/add_mux

HTTP service now supports registered statuses

CHANGELOG.md

@@ -4,6 +4,7 @@
 - [PR #309](https://github.com/rqlite/rqlite/pull/309): Tweak start-up logo.
 - [PR #308](https://github.com/rqlite/rqlite/pull/308): Move to clearer command-line options.
 - [PR #307](https://github.com/rqlite/rqlite/pull/307): Support node-to-node encryption. Fixes [issue #93](https://github.com/rqlite/rqlite/issues/93).
+- [PR #310](https://github.com/rqlite/rqlite/pull/310): HTTP service supports registration of Status providers; Mux is first client.
 
 ## 3.14.0 (May 4th 2017)
 - [PR #304](https://github.com/rqlite/rqlite/pull/304): Switch to Go 1.8.1.

cmd/rqlited/main.go

@@ -304,6 +304,12 @@ func main() {
 		log.Fatalf("failed to start HTTP server: %s", err.Error())
 	}
 
+	// Register cross-component statuses.
+	if err := s.RegisterStatus("mux", mux); err != nil {
+		log.Fatalf("failed to register mux status: %s", err.Error())
+	}
+
+	// Block until signalled.
 	terminate := make(chan os.Signal, 1)
 	signal.Notify(terminate, os.Interrupt)
 	<-terminate

http/service.go

@@ -16,6 +16,7 @@ import (
 	"os"
 	"runtime"
 	"strings"
+	"sync"
 	"time"
 
 	sql "github.com/rqlite/rqlite/db"
@@ -64,6 +65,11 @@ type CredentialStore interface {
 	HasPerm(username string, perm string) bool
 }
 
+// Statuser is the interface status providers must implement.
+type Statuser interface {
+	Stats() (interface{}, error)
+}
+
 // Response represents a response from the HTTP service.
 type Response struct {
 	Results interface{} `json:"results,omitempty"`
@@ -134,6 +140,9 @@ type Service struct {
 	start      time.Time // Start up time.
 	lastBackup time.Time // Time of last successful backup.
 
+	statusMu sync.RWMutex
+	statuses map[string]Statuser
+
 	CertFile string // Path to SSL certificate.
 	KeyFile  string // Path to SSL private key.
 
@@ -154,6 +163,7 @@ func New(addr string, store Store, credentials CredentialStore) *Service {
 		addr:            addr,
 		store:           store,
 		start:           time.Now(),
+		statuses:        make(map[string]Statuser),
 		credentialStore: credentials,
 		logger:          log.New(os.Stderr, "[http] ", log.LstdFlags),
 	}
@@ -243,6 +253,19 @@ func (s *Service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// RegisterStatus allows other modules to register status for serving over HTTP.
+func (s *Service) RegisterStatus(key string, stat Statuser) error {
+	s.statusMu.Lock()
+	defer s.statusMu.Unlock()
+
+	if _, ok := s.statuses[key]; ok {
+		return fmt.Errorf("status already registered with key %s", key)
+	}
+	s.statuses[key] = stat
+
+	return nil
+}
+
 // handleJoin handles cluster-join requests from other nodes.
 func (s *Service) handleJoin(w http.ResponseWriter, r *http.Request) {
 	if !s.CheckRequestPerm(r, PermJoin) {
@@ -470,6 +493,20 @@ func (s *Service) handleStatus(w http.ResponseWriter, r *http.Request) {
 		status["build"] = s.BuildInfo
 	}
 
+	// Add any registered statusers.
+	func() {
+		s.statusMu.RLock()
+		defer s.statusMu.RUnlock()
+		for k, v := range s.statuses {
+			stat, err := v.Stats()
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+			status[k] = stat
+		}
+	}()
+
 	pretty, _ := isPretty(r)
 	var b []byte
 	if pretty {

http/service_test.go

@@ -332,6 +332,20 @@ func Test_401Routes_BasicAuthBadPerm(t *testing.T) {
 	}
 }
 
+func Test_RegisterStatus(t *testing.T) {
+	var stats *mockStatuser
+	m := &MockStore{}
+	s := New("127.0.0.1:0", m, nil)
+
+	if err := s.RegisterStatus("foo", stats); err != nil {
+		t.Fatalf("failed to register statuser: %s", err.Error())
+	}
+
+	if err := s.RegisterStatus("foo", stats); err == nil {
+		t.Fatal("successfully re-registered statuser")
+	}
+}
+
 type MockStore struct {
 	executeFn func(queries []string, tx bool) ([]*sql.Result, error)
 	queryFn   func(queries []string, tx, leader, verify bool) ([]*sql.Rows, error)
@@ -387,3 +401,10 @@ func (m *mockCredentialStore) Check(username, password string) bool {
 func (m *mockCredentialStore) HasPerm(username, perm string) bool {
 	return m.HasPermOK
 }
+
+type mockStatuser struct {
+}
+
+func (m *mockStatuser) Stats() (interface{}, error) {
+	return nil, nil
+}

tcp/mux.go

@@ -8,6 +8,7 @@ import (
 	"log"
 	"net"
 	"os"
+	"strconv"
 	"sync"
 	"time"
 )
@@ -104,7 +105,7 @@ func NewMux(ln net.Listener, adv net.Addr) (*Mux, error) {
 		addr:    addr,
 		m:       make(map[byte]*listener),
 		Timeout: DefaultTimeout,
-		Logger:  log.New(os.Stderr, "[tcp] ", log.LstdFlags),
+		Logger:  log.New(os.Stderr, "[mux] ", log.LstdFlags),
 	}, nil
 }
 
@@ -156,6 +157,23 @@ func (mux *Mux) Serve() error {
 	}
 }
 
+// Stats returns status of the mux.
+func (mux *Mux) Stats() (interface{}, error) {
+	s := map[string]string{
+		"addr":      mux.addr.String(),
+		"timeout":   mux.Timeout.String(),
+		"encrypted": strconv.FormatBool(mux.remoteEncrypted),
+	}
+
+	if mux.remoteEncrypted {
+		s["certificate"] = mux.nodeX509Cert
+		s["key"] = mux.nodeX509Key
+		s["skip_verify"] = strconv.FormatBool(mux.InsecureSkipVerify)
+	}
+
+	return s, nil
+}
+
 func (mux *Mux) handleConn(conn net.Conn) {
 	defer mux.wg.Done()
 	// Set a read deadline so connections with no data don't timeout.