refactor(mediaserver): simplify API interactions

internal/domain/types.go

@@ -34,7 +34,6 @@ type Source struct {
 	Container     Container
 	Live          bool
 	LiveChangedAt time.Time
-	Listeners     int
 	Tracks        []string
 	RTMPURL       string
 	ExitReason    string

internal/mediaserver/actor.go

@@ -26,16 +26,16 @@ import (
 type StreamKey string
 
 const (
-	defaultFetchIngressStateInterval           = 5 * time.Second                           // default interval to fetch the state of the media server
-	defaultAPIPort                             = 9997                                      // default API host port for the media server
-	defaultRTMPIP                              = "127.0.0.1"                               // default RTMP host IP, bound to localhost for security
-	defaultRTMPPort                            = 1935                                      // default RTMP host port for the media server
-	defaultRTMPHost                            = "localhost"                               // default RTMP host name, used for the RTMP URL
-	defaultChanSize                            = 64                                        // default channel size for asynchronous non-error channels
-	imageNameMediaMTX                          = "ghcr.io/rfwatson/mediamtx-alpine:latest" // image name for mediamtx
-	defaultStreamKey                 StreamKey = "live"                                    // Default stream key. See [StreamKey].
-	componentName                              = "mediaserver"                             // component name, mostly used for Docker labels
-	httpClientTimeout                          = time.Second                               // timeout for outgoing HTTP client requests
+	defaultUpdateStateInterval           = 5 * time.Second                           // default interval to update the state of the media server
+	defaultAPIPort                       = 9997                                      // default API host port for the media server
+	defaultRTMPIP                        = "127.0.0.1"                               // default RTMP host IP, bound to localhost for security
+	defaultRTMPPort                      = 1935                                      // default RTMP host port for the media server
+	defaultRTMPHost                      = "localhost"                               // default RTMP host name, used for the RTMP URL
+	defaultChanSize                      = 64                                        // default channel size for asynchronous non-error channels
+	imageNameMediaMTX                    = "ghcr.io/rfwatson/mediamtx-alpine:latest" // image name for mediamtx
+	defaultStreamKey           StreamKey = "live"                                    // Default stream key. See [StreamKey].
+	componentName                        = "mediaserver"                             // component name, mostly used for Docker labels
+	httpClientTimeout                    = time.Second                               // timeout for outgoing HTTP client requests
 )
 
 // action is an action to be performed by the actor.
@@ -43,19 +43,19 @@ type action func()
 
 // Actor is responsible for managing the media server.
 type Actor struct {
-	actorC                    chan action
-	stateC                    chan domain.Source
-	chanSize                  int
-	containerClient           *container.Client
-	apiPort                   int
-	rtmpAddr                  domain.NetAddr
-	rtmpHost                  string
-	streamKey                 StreamKey
-	fetchIngressStateInterval time.Duration
-	pass                      string // password for the media server
-	tlsCert, tlsKey           []byte // TLS cert and key for the media server
-	logger                    *slog.Logger
-	apiClient                 *http.Client
+	actorC              chan action
+	stateC              chan domain.Source
+	chanSize            int
+	containerClient     *container.Client
+	apiPort             int
+	rtmpAddr            domain.NetAddr
+	rtmpHost            string
+	streamKey           StreamKey
+	updateStateInterval time.Duration
+	pass                string // password for the media server
+	tlsCert, tlsKey     []byte // TLS cert and key for the media server
+	logger              *slog.Logger
+	apiClient           *http.Client
 
 	// mutable state
 	state *domain.Source
@@ -64,14 +64,14 @@ type Actor struct {
 // NewActorParams contains the parameters for building a new media server
 // actor.
 type NewActorParams struct {
-	APIPort                   int            // defaults to 9997
-	RTMPAddr                  domain.NetAddr // defaults to 127.0.0.1:1935
-	RTMPHost                  string         // defaults to "localhost"
-	StreamKey                 StreamKey      // defaults to "live"
-	ChanSize                  int            // defaults to 64
-	FetchIngressStateInterval time.Duration  // defaults to 5 seconds
-	ContainerClient           *container.Client
-	Logger                    *slog.Logger
+	APIPort             int            // defaults to 9997
+	RTMPAddr            domain.NetAddr // defaults to 127.0.0.1:1935
+	RTMPHost            string         // defaults to "localhost"
+	StreamKey           StreamKey      // defaults to "live"
+	ChanSize            int            // defaults to 64
+	UpdateStateInterval time.Duration  // defaults to 5 seconds
+	ContainerClient     *container.Client
+	Logger              *slog.Logger
 }
 
 // NewActor creates a new media server actor.
@@ -93,21 +93,21 @@ func NewActor(ctx context.Context, params NewActorParams) (_ *Actor, err error)
 
 	chanSize := cmp.Or(params.ChanSize, defaultChanSize)
 	return &Actor{
-		apiPort:                   cmp.Or(params.APIPort, defaultAPIPort),
-		rtmpAddr:                  rtmpAddr,
-		rtmpHost:                  cmp.Or(params.RTMPHost, defaultRTMPHost),
-		streamKey:                 cmp.Or(params.StreamKey, defaultStreamKey),
-		fetchIngressStateInterval: cmp.Or(params.FetchIngressStateInterval, defaultFetchIngressStateInterval),
-		tlsCert:                   tlsCert,
-		tlsKey:                    tlsKey,
-		pass:                      generatePassword(),
-		actorC:                    make(chan action, chanSize),
-		state:                     new(domain.Source),
-		stateC:                    make(chan domain.Source, chanSize),
-		chanSize:                  chanSize,
-		containerClient:           params.ContainerClient,
-		logger:                    params.Logger,
-		apiClient:                 apiClient,
+		apiPort:             cmp.Or(params.APIPort, defaultAPIPort),
+		rtmpAddr:            rtmpAddr,
+		rtmpHost:            cmp.Or(params.RTMPHost, defaultRTMPHost),
+		streamKey:           cmp.Or(params.StreamKey, defaultStreamKey),
+		updateStateInterval: cmp.Or(params.UpdateStateInterval, defaultUpdateStateInterval),
+		tlsCert:             tlsCert,
+		tlsKey:              tlsKey,
+		pass:                generatePassword(),
+		actorC:              make(chan action, chanSize),
+		state:               new(domain.Source),
+		stateC:              make(chan domain.Source, chanSize),
+		chanSize:            chanSize,
+		containerClient:     params.ContainerClient,
+		logger:              params.Logger,
+		apiClient:           apiClient,
 	}, nil
 }
 
@@ -255,16 +255,8 @@ func (s *Actor) Close() error {
 // actorLoop is the main loop of the media server actor. It exits when the
 // actor is closed, or the parent context is cancelled.
 func (s *Actor) actorLoop(ctx context.Context, containerStateC <-chan domain.Container, errC <-chan error) {
-	fetchStateT := time.NewTicker(s.fetchIngressStateInterval)
-	defer fetchStateT.Stop()
-
-	// fetchTracksT is used to signal that tracks should be fetched from the
-	// media server, after the stream goes on-air. A short delay is needed due to
-	// workaround a race condition in the media server.
-	var fetchTracksT *time.Timer
-	resetFetchTracksT := func(d time.Duration) { fetchTracksT = time.NewTimer(d) }
-	resetFetchTracksT(time.Second)
-	fetchTracksT.Stop()
+	updateStateT := time.NewTicker(s.updateStateInterval)
+	defer updateStateT.Stop()
 
 	sendState := func() { s.stateC <- *s.state }
 
@@ -274,7 +266,7 @@ func (s *Actor) actorLoop(ctx context.Context, containerStateC <-chan domain.Con
 			s.state.Container = containerState
 
 			if s.state.Container.Status == domain.ContainerStatusExited {
-				fetchStateT.Stop()
+				updateStateT.Stop()
 				s.handleContainerExit(nil)
 			}
 
@@ -293,43 +285,21 @@ func (s *Actor) actorLoop(ctx context.Context, containerStateC <-chan domain.Con
 				s.logger.Error("Error from container client", "err", err, "id", shortID(s.state.Container.ID))
 			}
 
-			fetchStateT.Stop()
+			updateStateT.Stop()
 			s.handleContainerExit(err)
 
 			sendState()
-		case <-fetchStateT.C:
-			ingressState, err := fetchIngressState(s.rtmpConnsURL(), s.streamKey, s.apiClient)
+		case <-updateStateT.C:
+			path, err := fetchPath(s.pathURL(string(s.streamKey)), s.apiClient)
 			if err != nil {
-				s.logger.Error("Error fetching server state", "err", err)
+				s.logger.Error("Error fetching path", "err", err)
 				continue
 			}
 
-			var shouldSendState bool
-			if ingressState.ready != s.state.Live {
-				s.state.Live = ingressState.ready
+			if path.Ready != s.state.Live {
+				s.state.Live = path.Ready
 				s.state.LiveChangedAt = time.Now()
-				resetFetchTracksT(time.Second)
-				shouldSendState = true
-			}
-			if ingressState.listeners != s.state.Listeners {
-				s.state.Listeners = ingressState.listeners
-				shouldSendState = true
-			}
-			if shouldSendState {
-				sendState()
-			}
-		case <-fetchTracksT.C:
-			if !s.state.Live {
-				continue
-			}
-
-			if tracks, err := fetchTracks(s.pathsURL(), s.streamKey, s.apiClient); err != nil {
-				s.logger.Error("Error fetching tracks", "err", err)
-				resetFetchTracksT(3 * time.Second)
-			} else if len(tracks) == 0 {
-				resetFetchTracksT(time.Second)
-			} else {
-				s.state.Tracks = tracks
+				s.state.Tracks = path.Tracks
 				sendState()
 			}
 		case action, ok := <-s.actorC:
@@ -369,15 +339,9 @@ func (s *Actor) RTMPInternalURL() string {
 	return fmt.Sprintf("rtmp://mediaserver:1935/%s?user=api&pass=%s", s.streamKey, s.pass)
 }
 
-// rtmpConnsURL returns the URL for fetching RTMP connections, accessible from
-// the host.
-func (s *Actor) rtmpConnsURL() string {
-	return fmt.Sprintf("https://api:%s@localhost:%d/v3/rtmpconns/list", s.pass, s.apiPort)
-}
-
-// pathsURL returns the URL for fetching paths, accessible from the host.
-func (s *Actor) pathsURL() string {
-	return fmt.Sprintf("https://api:%s@localhost:%d/v3/paths/list", s.pass, s.apiPort)
+// pathURL returns the URL for fetching a path, accessible from the host.
+func (s *Actor) pathURL(path string) string {
+	return fmt.Sprintf("https://api:%s@localhost:%d/v3/paths/get/%s", s.pass, s.apiPort, path)
 }
 
 // healthCheckURL returns the URL for the health check, accessible from the

internal/mediaserver/api.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"time"
 )
 
 type httpClient interface {
@@ -44,109 +43,37 @@ func buildAPIClient(certPEM []byte) (*http.Client, error) {
 
 const userAgent = "octoplex-client"
 
-type apiResponse[T any] struct {
-	Items []T `json:"items"`
-}
-
-type rtmpConnsResponse struct {
-	ID            string    `json:"id"`
-	CreatedAt     time.Time `json:"created"`
-	State         string    `json:"state"`
-	Path          string    `json:"path"`
-	BytesReceived int64     `json:"bytesReceived"`
-	BytesSent     int64     `json:"bytesSent"`
-	RemoteAddr    string    `json:"remoteAddr"`
-}
-
-type ingressStreamState struct {
-	ready     bool
-	listeners int
-}
-
-// TODO: handle pagination
-func fetchIngressState(apiURL string, streamKey StreamKey, httpClient httpClient) (state ingressStreamState, _ error) {
-	req, err := http.NewRequest(http.MethodGet, apiURL, nil)
-	if err != nil {
-		return state, fmt.Errorf("new request: %w", err)
-	}
-	req.Header.Set("User-Agent", userAgent)
-
-	httpResp, err := httpClient.Do(req)
-	if err != nil {
-		return state, fmt.Errorf("do request: %w", err)
-	}
-
-	if httpResp.StatusCode != http.StatusOK {
-		return state, fmt.Errorf("unexpected status code: %d", httpResp.StatusCode)
-	}
-
-	respBody, err := io.ReadAll(httpResp.Body)
-	if err != nil {
-		return state, fmt.Errorf("read body: %w", err)
-	}
-
-	var resp apiResponse[rtmpConnsResponse]
-	if err = json.Unmarshal(respBody, &resp); err != nil {
-		return state, fmt.Errorf("unmarshal: %w", err)
-	}
-
-	for _, conn := range resp.Items {
-		if conn.Path != string(streamKey) {
-			continue
-		}
-
-		switch conn.State {
-		case "publish":
-			// mediamtx may report a stream as being in publish state via the API,
-			// but still refuse to serve them due to being unpublished. This seems to
-			// be a bug, this is a hacky workaround.
-			state.ready = conn.BytesReceived > 20_000
-		case "read":
-			state.listeners++
-		}
-	}
-
-	return state, nil
-}
-
-type path struct {
+type apiPath struct {
 	Name   string   `json:"name"`
+	Ready  bool     `json:"ready"`
 	Tracks []string `json:"tracks"`
 }
 
-// TODO: handle pagination
-func fetchTracks(apiURL string, streamKey StreamKey, httpClient httpClient) ([]string, error) {
+func fetchPath(apiURL string, httpClient httpClient) (apiPath, error) {
 	req, err := http.NewRequest(http.MethodGet, apiURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("new request: %w", err)
+		return apiPath{}, fmt.Errorf("new request: %w", err)
 	}
 	req.Header.Set("User-Agent", userAgent)
 
 	httpResp, err := httpClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("do request: %w", err)
+		return apiPath{}, fmt.Errorf("do request: %w", err)
 	}
 
 	if httpResp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("unexpected status code: %d", httpResp.StatusCode)
+		return apiPath{}, fmt.Errorf("unexpected status code: %d", httpResp.StatusCode)
 	}
 
 	respBody, err := io.ReadAll(httpResp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("read body: %w", err)
+		return apiPath{}, fmt.Errorf("read body: %w", err)
 	}
 
-	var resp apiResponse[path]
-	if err = json.Unmarshal(respBody, &resp); err != nil {
-		return nil, fmt.Errorf("unmarshal: %w", err)
+	var path apiPath
+	if err = json.Unmarshal(respBody, &path); err != nil {
+		return apiPath{}, fmt.Errorf("unmarshal: %w", err)
 	}
 
-	var tracks []string
-	for _, path := range resp.Items {
-		if path.Name == string(streamKey) {
-			tracks = path.Tracks
-		}
-	}
-
-	return tracks, nil
+	return path, nil
 }

internal/mediaserver/api_test.go

@@ -12,14 +12,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestFetchIngressState(t *testing.T) {
-	const url = "http://localhost:8989/v3/rtmpconns/list"
+func TestFetchPath(t *testing.T) {
+	const url = "http://localhost:8989/v3/paths/get/live"
 
 	testCases := []struct {
 		name         string
 		httpResponse *http.Response
 		httpError    error
-		wantState    ingressStreamState
+		wantPath     apiPath
 		wantErr      error
 	}{
 		{
@@ -36,36 +36,20 @@ func TestFetchIngressState(t *testing.T) {
 			wantErr: errors.New("unmarshal: invalid character 'i' looking for beginning of value"),
 		},
 		{
-			name: "successful response, no streams",
+			name: "successful response, not ready",
 			httpResponse: &http.Response{
 				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":0,"pageCount":0,"items":[]}`))),
+				Body:       io.NopCloser(bytes.NewReader([]byte(`{"name":"live","confName":"live","source":null,"ready":false,"readyTime":null,"tracks":[],"bytesReceived":0,"bytesSent":0,"readers":[]}`))),
 			},
-			wantState: ingressStreamState{ready: false, listeners: 0},
-		},
-		{
-			name: "successful response, not yet ready",
-			httpResponse: &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":1,"pageCount":1,"items":[{"id":"d2953cf8-9cd6-4c30-816f-807b80b6a71f","created":"2025-02-15T08:19:00.616220354Z","remoteAddr":"172.17.0.1:32972","state":"publish","path":"live","query":"","bytesReceived":15462,"bytesSent":3467}]}`))),
-			},
-			wantState: ingressStreamState{ready: false, listeners: 0},
+			wantPath: apiPath{Name: "live", Ready: false, Tracks: []string{}},
 		},
 		{
 			name: "successful response, ready",
 			httpResponse: &http.Response{
 				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":1,"pageCount":1,"items":[{"id":"d2953cf8-9cd6-4c30-816f-807b80b6a71f","created":"2025-02-15T08:19:00.616220354Z","remoteAddr":"172.17.0.1:32972","state":"publish","path":"live","query":"","bytesReceived":27832,"bytesSent":3467}]}`))),
+				Body:       io.NopCloser(bytes.NewReader([]byte(`{"name":"live","confName":"live","source":{"type":"rtmpConn","id":"fd2d79a8-bab9-4141-a1b5-55bd1a8649df"},"ready":true,"readyTime":"2025-04-18T07:44:53.683627506Z","tracks":["H264"],"bytesReceived":254677,"bytesSent":0,"readers":[]}`))),
 			},
-			wantState: ingressStreamState{ready: true, listeners: 0},
-		},
-		{
-			name: "successful response, ready, with listeners",
-			httpResponse: &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":2,"pageCount":1,"items":[{"id":"12668315-0572-41f1-8384-fe7047cc73be","created":"2025-02-15T08:23:43.836589664Z","remoteAddr":"172.17.0.1:40026","state":"publish","path":"live","query":"","bytesReceived":7180753,"bytesSent":3467},{"id":"079370fd-43bb-4798-b079-860cc3159e4e","created":"2025-02-15T08:24:32.396794364Z","remoteAddr":"192.168.48.3:44736","state":"read","path":"live","query":"","bytesReceived":333435,"bytesSent":24243}]}`))),
-			},
-			wantState: ingressStreamState{ready: true, listeners: 1},
+			wantPath: apiPath{Name: "live", Ready: true, Tracks: []string{"H264"}},
 		},
 	}
 
@@ -79,74 +63,12 @@ func TestFetchIngressState(t *testing.T) {
 				})).
 				Return(tc.httpResponse, tc.httpError)
 
-			state, err := fetchIngressState(url, StreamKey("live"), &httpClient)
+			path, err := fetchPath(url, &httpClient)
 			if tc.wantErr != nil {
 				require.EqualError(t, err, tc.wantErr.Error())
 			} else {
 				require.NoError(t, err)
-				require.Equal(t, tc.wantState, state)
-			}
-		})
-	}
-}
-
-func TestFetchTracks(t *testing.T) {
-	const url = "http://localhost:8989/v3/paths/list"
-
-	testCases := []struct {
-		name         string
-		httpResponse *http.Response
-		httpError    error
-		wantTracks   []string
-		wantErr      error
-	}{
-		{
-			name:         "non-200 status",
-			httpResponse: &http.Response{StatusCode: http.StatusNotFound},
-			wantErr:      errors.New("unexpected status code: 404"),
-		},
-		{
-			name: "unparseable response",
-			httpResponse: &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte("invalid json"))),
-			},
-			wantErr: errors.New("unmarshal: invalid character 'i' looking for beginning of value"),
-		},
-		{
-			name: "successful response, no tracks",
-			httpResponse: &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":1,"pageCount":1,"items":[{"name":"live","confName":"all_others","source":{"type":"rtmpConn","id":"287340b2-04c2-4fcc-ab9c-089f4ff15aeb"},"ready":true,"readyTime":"2025-02-22T17:26:05.527206818Z","tracks":[],"bytesReceived":94430983,"bytesSent":0,"readers":[]}]}`))),
-			},
-			wantTracks: []string{},
-		},
-		{
-			name: "successful response, tracks",
-			httpResponse: &http.Response{
-				StatusCode: http.StatusOK,
-				Body:       io.NopCloser(bytes.NewReader([]byte(`{"itemCount":1,"pageCount":1,"items":[{"name":"live","confName":"all_others","source":{"type":"rtmpConn","id":"287340b2-04c2-4fcc-ab9c-089f4ff15aeb"},"ready":true,"readyTime":"2025-02-22T17:26:05.527206818Z","tracks":["H264","MPEG-4 Audio"],"bytesReceived":94430983,"bytesSent":0,"readers":[]}]}`))),
-			},
-			wantTracks: []string{"H264", "MPEG-4 Audio"},
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			var httpClient mocks.HTTPClient
-			httpClient.
-				EXPECT().
-				Do(mock.MatchedBy(func(req *http.Request) bool {
-					return req.URL.String() == url && req.Method == http.MethodGet
-				})).
-				Return(tc.httpResponse, tc.httpError)
-
-			tracks, err := fetchTracks(url, StreamKey("live"), &httpClient)
-			if tc.wantErr != nil {
-				require.EqualError(t, err, tc.wantErr.Error())
-			} else {
-				require.NoError(t, err)
-				require.Equal(t, tc.wantTracks, tracks)
+				require.Equal(t, tc.wantPath, path)
 			}
 		})
 	}