Implement system info API endpoint (#136)

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/pion/stun v0.6.1
 	github.com/pion/webrtc/v3 v3.2.37
 	github.com/prometheus/client_golang v1.15.0
+	github.com/prometheus/procfs v0.9.0
 	github.com/stretchr/testify v1.9.0
 	github.com/vmihailenco/msgpack/v5 v5.4.1
 	golang.org/x/crypto v0.22.0
@@ -60,7 +61,6 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_model v0.3.0 // indirect
 	github.com/prometheus/common v0.42.0 // indirect
-	github.com/prometheus/procfs v0.9.0 // indirect
 	github.com/rogpeppe/go-internal v1.10.0 // indirect
 	github.com/sirupsen/logrus v1.9.3 // indirect
 	github.com/tinylib/msgp v1.1.9 // indirect

service/client.go

@@ -232,6 +232,17 @@ func (c *Client) Send(msg ClientMessage) error {
 	return c.wsClient.Send(ws.BinaryMessage, data)
 }
 
+func (c *Client) Connected() bool {
+	c.mut.RLock()
+	defer c.mut.RUnlock()
+
+	if c.closed || c.wsClient == nil {
+		return false
+	}
+
+	return c.wsClient.GetConnState() == ws.WSConnOpen
+}
+
 func (c *Client) ReceiveCh() <-chan ClientMessage {
 	return c.receiveCh
 }
@@ -369,3 +380,31 @@ func (c *Client) GetVersionInfo() (VersionInfo, error) {
 
 	return info, nil
 }
+
+func (c *Client) GetSystemInfo() (SystemInfo, error) {
+	if c.httpClient == nil {
+		return SystemInfo{}, fmt.Errorf("http client is not initialized")
+	}
+
+	req, err := http.NewRequest("GET", c.cfg.httpURL+"/system", nil)
+	if err != nil {
+		return SystemInfo{}, fmt.Errorf("failed to build request: %w", err)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return SystemInfo{}, fmt.Errorf("http request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var info SystemInfo
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return SystemInfo{}, fmt.Errorf("decoding http response failed: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return SystemInfo{}, fmt.Errorf("request failed with status %s", resp.Status)
+	}
+
+	return info, nil
+}

service/client_test.go

@@ -756,3 +756,23 @@ func TestReconnectClientHerd(t *testing.T) {
 	// We wait for all clients to reconnect successfully.
 	reconnectWg.Wait()
 }
+
+func TestClientGetSystemInfo(t *testing.T) {
+	th := SetupTestHelper(t, nil)
+	defer th.Teardown()
+
+	c, err := NewClient(ClientConfig{
+		URL:     th.apiURL,
+		AuthKey: th.srvc.cfg.API.Security.AdminSecretKey,
+	})
+	require.NoError(t, err)
+	require.NotNil(t, c)
+	defer c.Close()
+
+	t.Run("success", func(t *testing.T) {
+		info, err := c.GetSystemInfo()
+		require.NoError(t, err)
+		require.NotEmpty(t, info)
+		require.NotEmpty(t, info)
+	})
+}

service/service.go

@@ -19,8 +19,10 @@ import (
 	"github.com/mattermost/rtcd/service/store"
 	"github.com/mattermost/rtcd/service/ws"
 
-	godeltaprof "github.com/grafana/pyroscope-go/godeltaprof/http/pprof"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
+
+	godeltaprof "github.com/grafana/pyroscope-go/godeltaprof/http/pprof"
+	"github.com/prometheus/procfs"
 )
 
 type Service struct {
@@ -31,6 +33,7 @@ type Service struct {
 	store        store.Store
 	auth         *auth.Service
 	metrics      *perf.Metrics
+	proc         procfs.FS
 	log          *mlog.Logger
 	sessionCache *auth.SessionCache
 	// connMap maps user sessions to the websocket connection they originated
@@ -60,6 +63,12 @@ func New(cfg Config) (*Service, error) {
 
 	s.log.Info("rtcd: starting up", getVersionInfo().logFields()...)
 
+	proc, err := procfs.NewDefaultFS()
+	if err != nil {
+		s.log.Error("failed to create proc file-system", mlog.Err(err))
+	}
+	s.proc = proc
+
 	s.store, err = store.New(cfg.Store.DataSource)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create store: %w", err)
@@ -102,6 +111,7 @@ func New(cfg Config) (*Service, error) {
 	s.apiServer.RegisterHandleFunc("/register", s.registerClient)
 	s.apiServer.RegisterHandleFunc("/unregister", s.unregisterClient)
 	s.apiServer.RegisterHandler("/ws", s.wsServer)
+	s.apiServer.RegisterHandleFunc("/system", s.getSystemInfo)
 
 	if val := os.Getenv("PERF_PROFILES"); val == "true" {
 		runtime.SetMutexProfileFraction(5)

service/system.go

@@ -0,0 +1,37 @@
+// Copyright (c) 2022-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package service
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
+
+	"github.com/prometheus/procfs"
+)
+
+type SystemInfo struct {
+	Load procfs.LoadAvg `json:"load"`
+}
+
+func (s *Service) getSystemInfo(w http.ResponseWriter, req *http.Request) {
+	if req.Method != http.MethodGet {
+		http.NotFound(w, req)
+		return
+	}
+
+	var info SystemInfo
+	avg, err := s.proc.LoadAvg()
+	if err == nil {
+		info.Load = *avg
+	} else {
+		s.log.Error("failed to get load average", mlog.Err(err))
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(&info); err != nil {
+		s.log.Error("failed to encode data", mlog.Err(err))
+	}
+}

service/system_test.go

@@ -0,0 +1,34 @@
+// Copyright (c) 2022-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package service
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetSystem(t *testing.T) {
+	th := SetupTestHelper(t, nil)
+	defer th.Teardown()
+
+	t.Run("invalid method", func(t *testing.T) {
+		resp, err := http.Post(th.apiURL+"/system", "", nil)
+		require.NoError(t, err)
+		require.Equal(t, http.StatusNotFound, resp.StatusCode)
+	})
+
+	t.Run("valid response", func(t *testing.T) {
+		resp, err := http.Get(th.apiURL + "/system")
+		require.NoError(t, err)
+		require.Equal(t, http.StatusOK, resp.StatusCode)
+		defer resp.Body.Close()
+		var info SystemInfo
+		err = json.NewDecoder(resp.Body).Decode(&info)
+		require.NoError(t, err)
+		require.NotEmpty(t, info.Load)
+	})
+}

service/ws/client.go

@@ -17,9 +17,9 @@ import (
 )
 
 const (
-	wsConnClosed int32 = iota
-	wsConnOpen
-	wsConnClosing
+	WSConnClosed int32 = iota
+	WSConnOpen
+	WSConnClosing
 )
 
 type Client struct {
@@ -86,7 +86,7 @@ func NewClient(cfg ClientConfig, opts ...ClientOption) (*Client, error) {
 	c.wg.Add(2)
 	go c.connReader()
 	go c.connWriter()
-	c.setConnState(wsConnOpen)
+	c.setConnState(WSConnOpen)
 
 	return c, nil
 }
@@ -98,7 +98,7 @@ func (c *Client) connReader() {
 		close(c.conn.closeCh)
 		c.wg.Wait()
 		close(c.errorCh)
-		c.setConnState(wsConnClosed)
+		c.setConnState(WSConnClosed)
 	}()
 
 	c.conn.ws.SetReadLimit(connMaxReadBytes)
@@ -164,7 +164,7 @@ func (c *Client) connWriter() {
 }
 
 func (c *Client) sendError(err error) {
-	if c.getConnState() != wsConnOpen {
+	if c.GetConnState() != WSConnOpen {
 		return
 	}
 	select {
@@ -176,7 +176,7 @@ func (c *Client) sendError(err error) {
 
 // SendMsg sends a WebSocket message with the specified type and data.
 func (c *Client) Send(mt MessageType, data []byte) error {
-	if c.getConnState() != wsConnOpen {
+	if c.GetConnState() != WSConnOpen {
 		return fmt.Errorf("failed to send message: connection is closed")
 	}
 
@@ -206,7 +206,7 @@ func (c *Client) ErrorCh() <-chan error {
 
 // Close closes the underlying WebSocket connection.
 func (c *Client) Close() error {
-	c.setConnState(wsConnClosing)
+	c.setConnState(WSConnClosing)
 	if err := c.flush(); err != nil {
 		return err
 	}
@@ -219,7 +219,7 @@ func (c *Client) setConnState(st int32) {
 	atomic.StoreInt32(&c.connState, st)
 }
 
-func (c *Client) getConnState() int32 {
+func (c *Client) GetConnState() int32 {
 	return atomic.LoadInt32(&c.connState)
 }