add runOnUnDemand hook (#2645)

README.md

@@ -1311,20 +1311,28 @@ paths:
 `runOnDemand` allows to run a command when a path is requested by a reader. This can be used to publish a stream on demand:
 
 ```yml
-paths:
+pathDefaults:
-  mypath:
+  # Command to run when this path is requested by a reader
-    # Command to run when this path is requested by a reader
+  # and no one is publishing to this path yet.
-    # and no one is publishing to this path yet.
+  # This is terminated with SIGINT when there are no readers anymore.
-    # This is terminated with SIGINT when the program closes.
+  # The following environment variables are available:
-    # The following environment variables are available:
+  # * MTX_PATH: path name
-    # * MTX_PATH: path name
+  # * MTX_QUERY: query parameters (passed by first reader)
-    # * MTX_QUERY: query parameters (passed by first reader)
+  # * RTSP_PORT: RTSP server port
-    # * RTSP_PORT: RTSP server port
+  # * G1, G2, ...: regular expression groups, if path name is
-    # * G1, G2, ...: regular expression groups, if path name is
+  #   a regular expression.
-    #   a regular expression.
+  runOnDemand: ffmpeg -i my_file.mp4 -c copy -f rtsp rtsp://localhost:8554/mypath
-    runOnDemand: ffmpeg -i my_file.mp4 -c copy -f rtsp rtsp://localhost:8554/mypath
+  # Restart the command if it exits.
-    # Restart the command if it exits.
+  runOnDemandRestart: no
-    runOnDemandRestart: no
+```
+
+`runOnUnDemand` allows to run a command when there are no readers anymore:
+
+```yml
+pathDefaults:
+  # Command to run when there are no readers anymore.
+  # Environment variables are the same of runOnDemand.
+  runOnUnDemand:
 ```
 
 `runOnReady` allows to run a command when a stream is ready to be read:

apidocs/openapi.yaml

@@ -344,6 +344,8 @@ components:
           type: string
         runOnDemandCloseAfter:
           type: string
+        runOnUnDemand:
+          type: string
         runOnReady:
           type: string
         runOnReadyRestart:

internal/conf/path.go

@@ -135,6 +135,7 @@ type Path struct {
 	RunOnDemandRestart         bool           `json:"runOnDemandRestart"`
 	RunOnDemandStartTimeout    StringDuration `json:"runOnDemandStartTimeout"`
 	RunOnDemandCloseAfter      StringDuration `json:"runOnDemandCloseAfter"`
+	RunOnUnDemand              string         `json:"runOnUnDemand"`
 	RunOnReady                 string         `json:"runOnReady"`
 	RunOnReadyRestart          bool           `json:"runOnReadyRestart"`
 	RunOnNotReady              string         `json:"runOnNotReady"`
@@ -489,8 +490,8 @@ func (pconf *Path) check(conf *Conf, name string) error {
 		return fmt.Errorf("a path with a regular expression (or path 'all')" +
 			" does not support option 'runOnInit'; use another path")
 	}
-	if pconf.RunOnDemand != "" && pconf.Source != "publisher" {
+	if (pconf.RunOnDemand != "" || pconf.RunOnUnDemand != "") && pconf.Source != "publisher" {
-		return fmt.Errorf("'runOnDemand' can be used only when source is 'publisher'")
+		return fmt.Errorf("'runOnDemand' and 'runOnUnDemand' can be used only when source is 'publisher'")
 	}
 
 	return nil

internal/core/conn.go

@@ -1,8 +1,6 @@
 package core
 
 import (
-	"net"
-
 	"github.com/bluenviron/mediamtx/internal/defs"
 	"github.com/bluenviron/mediamtx/internal/externalcmd"
 	"github.com/bluenviron/mediamtx/internal/logger"
@@ -16,7 +14,7 @@ type conn struct {
 	externalCmdPool     *externalcmd.Pool
 	logger              logger.Writer
 
-	onConnectCmd *externalcmd.Cmd
+	onDisconnectHook func()
 }
 
 func newConn(
@@ -38,48 +36,9 @@ func newConn(
 }
 
 func (c *conn) open(desc defs.APIPathSourceOrReader) {
-	if c.runOnConnect != "" {
+	c.onDisconnectHook = onConnectHook(c, desc)
-		c.logger.Log(logger.Info, "runOnConnect command started")
-
-		_, port, _ := net.SplitHostPort(c.rtspAddress)
-		env := externalcmd.Environment{
-			"RTSP_PORT":     port,
-			"MTX_CONN_TYPE": desc.Type,
-			"MTX_CONN_ID":   desc.ID,
-		}
-
-		c.onConnectCmd = externalcmd.NewCmd(
-			c.externalCmdPool,
-			c.runOnConnect,
-			c.runOnConnectRestart,
-			env,
-			func(err error) {
-				c.logger.Log(logger.Info, "runOnConnect command exited: %v", err)
-			})
-	}
 }
 
-func (c *conn) close(desc defs.APIPathSourceOrReader) {
+func (c *conn) close() {
-	if c.onConnectCmd != nil {
+	c.onDisconnectHook()
-		c.onConnectCmd.Close()
-		c.logger.Log(logger.Info, "runOnConnect command stopped")
-	}
-
-	if c.runOnDisconnect != "" {
-		c.logger.Log(logger.Info, "runOnDisconnect command launched")
-
-		_, port, _ := net.SplitHostPort(c.rtspAddress)
-		env := externalcmd.Environment{
-			"RTSP_PORT":     port,
-			"MTX_CONN_TYPE": desc.Type,
-			"MTX_CONN_ID":   desc.ID,
-		}
-
-		externalcmd.NewCmd(
-			c.externalCmdPool,
-			c.runOnDisconnect,
-			false,
-			env,
-			nil)
-	}
 }

internal/core/hooks.go

@@ -0,0 +1,208 @@
+package core
+
+import (
+	"net"
+
+	"github.com/bluenviron/mediamtx/internal/conf"
+	"github.com/bluenviron/mediamtx/internal/defs"
+	"github.com/bluenviron/mediamtx/internal/externalcmd"
+	"github.com/bluenviron/mediamtx/internal/logger"
+)
+
+func onInitHook(path *path) func() {
+	var onInitCmd *externalcmd.Cmd
+
+	if path.conf.RunOnInit != "" {
+		path.Log(logger.Info, "runOnInit command started")
+		onInitCmd = externalcmd.NewCmd(
+			path.externalCmdPool,
+			path.conf.RunOnInit,
+			path.conf.RunOnInitRestart,
+			path.externalCmdEnv(),
+			func(err error) {
+				path.Log(logger.Info, "runOnInit command exited: %v", err)
+			})
+	}
+
+	return func() {
+		if onInitCmd != nil {
+			onInitCmd.Close()
+			path.Log(logger.Info, "runOnInit command stopped")
+		}
+	}
+}
+
+func onConnectHook(c *conn, desc defs.APIPathSourceOrReader) func() {
+	var env externalcmd.Environment
+	var onConnectCmd *externalcmd.Cmd
+
+	if c.runOnConnect != "" || c.runOnDisconnect != "" {
+		_, port, _ := net.SplitHostPort(c.rtspAddress)
+		env = externalcmd.Environment{
+			"RTSP_PORT":     port,
+			"MTX_CONN_TYPE": desc.Type,
+			"MTX_CONN_ID":   desc.ID,
+		}
+	}
+
+	if c.runOnConnect != "" {
+		c.logger.Log(logger.Info, "runOnConnect command started")
+
+		onConnectCmd = externalcmd.NewCmd(
+			c.externalCmdPool,
+			c.runOnConnect,
+			c.runOnConnectRestart,
+			env,
+			func(err error) {
+				c.logger.Log(logger.Info, "runOnConnect command exited: %v", err)
+			})
+	}
+
+	return func() {
+		if onConnectCmd != nil {
+			onConnectCmd.Close()
+			c.logger.Log(logger.Info, "runOnConnect command stopped")
+		}
+
+		if c.runOnDisconnect != "" {
+			c.logger.Log(logger.Info, "runOnDisconnect command launched")
+			externalcmd.NewCmd(
+				c.externalCmdPool,
+				c.runOnDisconnect,
+				false,
+				env,
+				nil)
+		}
+	}
+}
+
+func onDemandHook(path *path, query string) func(string) {
+	var env externalcmd.Environment
+	var onDemandCmd *externalcmd.Cmd
+
+	if path.conf.RunOnDemand != "" || path.conf.RunOnUnDemand != "" {
+		env = path.externalCmdEnv()
+		env["MTX_QUERY"] = query
+	}
+
+	if path.conf.RunOnDemand != "" {
+		path.Log(logger.Info, "runOnDemand command started")
+
+		onDemandCmd = externalcmd.NewCmd(
+			path.externalCmdPool,
+			path.conf.RunOnDemand,
+			path.conf.RunOnDemandRestart,
+			env,
+			func(err error) {
+				path.Log(logger.Info, "runOnDemand command exited: %v", err)
+			})
+	}
+
+	return func(reason string) {
+		if onDemandCmd != nil {
+			onDemandCmd.Close()
+			path.Log(logger.Info, "runOnDemand command stopped: %v", reason)
+		}
+
+		if path.conf.RunOnUnDemand != "" {
+			path.Log(logger.Info, "runOnUnDemand command launched")
+			externalcmd.NewCmd(
+				path.externalCmdPool,
+				path.conf.RunOnUnDemand,
+				false,
+				env,
+				nil)
+		}
+	}
+}
+
+func onReadyHook(path *path) func() {
+	var env externalcmd.Environment
+	var onReadyCmd *externalcmd.Cmd
+
+	if path.conf.RunOnReady != "" || path.conf.RunOnNotReady != "" {
+		env = path.externalCmdEnv()
+		desc := path.source.APISourceDescribe()
+		env["MTX_QUERY"] = path.publisherQuery
+		env["MTX_SOURCE_TYPE"] = desc.Type
+		env["MTX_SOURCE_ID"] = desc.ID
+	}
+
+	if path.conf.RunOnReady != "" {
+		path.Log(logger.Info, "runOnReady command started")
+		onReadyCmd = externalcmd.NewCmd(
+			path.externalCmdPool,
+			path.conf.RunOnReady,
+			path.conf.RunOnReadyRestart,
+			env,
+			func(err error) {
+				path.Log(logger.Info, "runOnReady command exited: %v", err)
+			})
+	}
+
+	return func() {
+		if onReadyCmd != nil {
+			onReadyCmd.Close()
+			path.Log(logger.Info, "runOnReady command stopped")
+		}
+
+		if path.conf.RunOnNotReady != "" {
+			path.Log(logger.Info, "runOnNotReady command launched")
+			externalcmd.NewCmd(
+				path.externalCmdPool,
+				path.conf.RunOnNotReady,
+				false,
+				env,
+				nil)
+		}
+	}
+}
+
+func onReadHook(
+	externalCmdPool *externalcmd.Pool,
+	pathConf *conf.Path,
+	path *path,
+	reader defs.APIPathSourceOrReader,
+	query string,
+	l logger.Writer,
+) func() {
+	var env externalcmd.Environment
+	var onReadCmd *externalcmd.Cmd
+
+	if pathConf.RunOnRead != "" || pathConf.RunOnUnread != "" {
+		env = path.externalCmdEnv()
+		desc := reader
+		env["MTX_QUERY"] = query
+		env["MTX_READER_TYPE"] = desc.Type
+		env["MTX_READER_ID"] = desc.ID
+	}
+
+	if pathConf.RunOnRead != "" {
+		l.Log(logger.Info, "runOnRead command started")
+		onReadCmd = externalcmd.NewCmd(
+			externalCmdPool,
+			pathConf.RunOnRead,
+			pathConf.RunOnReadRestart,
+			env,
+			func(err error) {
+				l.Log(logger.Info, "runOnRead command exited: %v", err)
+			})
+	}
+
+	return func() {
+		if onReadCmd != nil {
+			onReadCmd.Close()
+			l.Log(logger.Info, "runOnRead command stopped")
+		}
+
+		if pathConf.RunOnUnread != "" {
+			l.Log(logger.Info, "runOnUnread command launched")
+			externalcmd.NewCmd(
+				externalCmdPool,
+				pathConf.RunOnUnread,
+				false,
+				env,
+				nil)
+		}
+	}
+}

internal/core/path.go

@@ -304,18 +304,7 @@ func (pa *path) run() {
 		}
 	}
 
-	var onInitCmd *externalcmd.Cmd
+	onUnInitHook := onInitHook(pa)
-	if pa.conf.RunOnInit != "" {
-		pa.Log(logger.Info, "runOnInit command started")
-		onInitCmd = externalcmd.NewCmd(
-			pa.externalCmdPool,
-			pa.conf.RunOnInit,
-			pa.conf.RunOnInitRestart,
-			pa.externalCmdEnv(),
-			func(err error) {
-				pa.Log(logger.Info, "runOnInit command exited: %v", err)
-			})
-	}
 
 	err := pa.runInner()
 
@@ -329,10 +318,7 @@ func (pa *path) run() {
 	pa.onDemandPublisherReadyTimer.Stop()
 	pa.onDemandPublisherCloseTimer.Stop()
 
-	if onInitCmd != nil {
+	onUnInitHook()
-		onInitCmd.Close()
-		pa.Log(logger.Info, "runOnInit command stopped")
-	}
 
 	for _, req := range pa.describeRequestsOnHold {
 		req.res <- pathDescribeRes{err: fmt.Errorf("terminated")}
@@ -802,7 +788,7 @@ func (pa *path) onDemandStaticSourceStop(reason string) {
 }
 
 func (pa *path) onDemandPublisherStart(query string) {
-	pa.onUnDemandHook = publisherOnDemandHook(pa, query)
+	pa.onUnDemandHook = onDemandHook(pa, query)
 
 	pa.onDemandPublisherReadyTimer.Stop()
 	pa.onDemandPublisherReadyTimer = time.NewTimer(time.Duration(pa.conf.RunOnDemandStartTimeout))
@@ -847,7 +833,7 @@ func (pa *path) setReady(desc *description.Session, allocateEncoder bool) error
 
 	pa.readyTime = time.Now()
 
-	pa.onNotReadyHook = sourceOnReadyHook(pa)
+	pa.onNotReadyHook = onReadyHook(pa)
 
 	pa.parent.pathReady(pa)
 

internal/core/path_test.go

@@ -84,6 +84,7 @@ func main() {
 
 func TestPathRunOnDemand(t *testing.T) {
 	onDemandFile := filepath.Join(os.TempDir(), "ondemand")
+	onUnDemandFile := filepath.Join(os.TempDir(), "ondisconnect")
 
 	srcFile := filepath.Join(os.TempDir(), "ondemand.go")
 	err := os.WriteFile(srcFile,
@@ -103,6 +104,7 @@ func TestPathRunOnDemand(t *testing.T) {
 	for _, ca := range []string{"describe", "setup", "describe and setup"} {
 		t.Run(ca, func(t *testing.T) {
 			defer os.Remove(onDemandFile)
+			defer os.Remove(onUnDemandFile)
 
 			p1, ok := newInstance(fmt.Sprintf("rtmp: no\n"+
 				"hls: no\n"+
@@ -110,7 +112,8 @@ func TestPathRunOnDemand(t *testing.T) {
 				"paths:\n"+
 				"  '~^(on)demand$':\n"+
 				"    runOnDemand: %s\n"+
-				"    runOnDemandCloseAfter: 1s\n", execFile))
+				"    runOnDemandCloseAfter: 1s\n"+
+				"    runOnUnDemand: touch %s\n", execFile, onUnDemandFile))
 			require.Equal(t, true, ok)
 			defer p1.Close()
 
@@ -185,6 +188,9 @@ func TestPathRunOnDemand(t *testing.T) {
 				}
 				time.Sleep(100 * time.Millisecond)
 			}
+
+			_, err := os.Stat(onUnDemandFile)
+			require.NoError(t, err)
 		})
 	}
 }

internal/core/publisher.go

@@ -1,39 +1,7 @@
 package core
 
-import (
-	"github.com/bluenviron/mediamtx/internal/externalcmd"
-	"github.com/bluenviron/mediamtx/internal/logger"
-)
-
 // publisher is an entity that can publish a stream.
 type publisher interface {
 	source
 	close()
 }
-
-func publisherOnDemandHook(path *path, query string) func(string) {
-	var onDemandCmd *externalcmd.Cmd
-
-	if path.conf.RunOnDemand != "" {
-		env := path.externalCmdEnv()
-		env["MTX_QUERY"] = query
-
-		path.Log(logger.Info, "runOnDemand command started")
-
-		onDemandCmd = externalcmd.NewCmd(
-			path.externalCmdPool,
-			path.conf.RunOnDemand,
-			path.conf.RunOnDemandRestart,
-			env,
-			func(err error) {
-				path.Log(logger.Info, "runOnDemand command exited: %v", err)
-			})
-	}
-
-	return func(reason string) {
-		if onDemandCmd != nil {
-			onDemandCmd.Close()
-			path.Log(logger.Info, "runOnDemand command stopped: %v", reason)
-		}
-	}
-}

internal/core/reader.go

@@ -2,10 +2,7 @@ package core
 
 import (
 	"github.com/bluenviron/mediamtx/internal/asyncwriter"
-	"github.com/bluenviron/mediamtx/internal/conf"
 	"github.com/bluenviron/mediamtx/internal/defs"
-	"github.com/bluenviron/mediamtx/internal/externalcmd"
-	"github.com/bluenviron/mediamtx/internal/logger"
 	"github.com/bluenviron/mediamtx/internal/stream"
 )
 
@@ -18,52 +15,3 @@ type reader interface {
 func readerMediaInfo(r *asyncwriter.Writer, stream *stream.Stream) string {
 	return mediaInfo(stream.MediasForReader(r))
 }
-
-func readerOnReadHook(
-	externalCmdPool *externalcmd.Pool,
-	pathConf *conf.Path,
-	path *path,
-	reader defs.APIPathSourceOrReader,
-	query string,
-	l logger.Writer,
-) func() {
-	var env externalcmd.Environment
-	var onReadCmd *externalcmd.Cmd
-
-	if pathConf.RunOnRead != "" || pathConf.RunOnUnread != "" {
-		env = path.externalCmdEnv()
-		desc := reader
-		env["MTX_QUERY"] = query
-		env["MTX_READER_TYPE"] = desc.Type
-		env["MTX_READER_ID"] = desc.ID
-	}
-
-	if pathConf.RunOnRead != "" {
-		l.Log(logger.Info, "runOnRead command started")
-		onReadCmd = externalcmd.NewCmd(
-			externalCmdPool,
-			pathConf.RunOnRead,
-			pathConf.RunOnReadRestart,
-			env,
-			func(err error) {
-				l.Log(logger.Info, "runOnRead command exited: %v", err)
-			})
-	}
-
-	return func() {
-		if onReadCmd != nil {
-			onReadCmd.Close()
-			l.Log(logger.Info, "runOnRead command stopped")
-		}
-
-		if pathConf.RunOnUnread != "" {
-			l.Log(logger.Info, "runOnUnread command launched")
-			externalcmd.NewCmd(
-				externalCmdPool,
-				pathConf.RunOnUnread,
-				false,
-				env,
-				nil)
-		}
-	}
-}

internal/core/rtmp_conn.go

@@ -151,7 +151,7 @@ func (c *rtmpConn) run() { //nolint:dupl
 
 	desc := c.apiReaderDescribe()
 	c.conn.open(desc)
-	defer c.conn.close(desc)
+	defer c.conn.close()
 
 	err := c.runInner()
 
@@ -256,7 +256,7 @@ func (c *rtmpConn) runRead(conn *rtmp.Conn, u *url.URL) error {
 
 	pathConf := res.path.safeConf()
 
-	onUnreadHook := readerOnReadHook(
+	onUnreadHook := onReadHook(
 		c.externalCmdPool,
 		pathConf,
 		res.path,

internal/core/rtsp_conn.go

@@ -114,15 +114,7 @@ func (c *rtspConn) ip() net.IP {
 func (c *rtspConn) onClose(err error) {
 	c.Log(logger.Info, "closed: %v", err)
 
-	c.conn.close(defs.APIPathSourceOrReader{
+	c.conn.close()
-		Type: func() string {
-			if c.isTLS {
-				return "rtspsConn"
-			}
-			return "rtspConn"
-		}(),
-		ID: c.uuid.String(),
-	})
 }
 
 // onRequest is called by rtspServer.

internal/core/rtsp_session.go

@@ -292,7 +292,7 @@ func (s *rtspSession) onPlay(_ *gortsplib.ServerHandlerOnPlayCtx) (*base.Respons
 
 		pathConf := s.path.safeConf()
 
-		s.onUnreadHook = readerOnReadHook(
+		s.onUnreadHook = onReadHook(
 			s.externalCmdPool,
 			pathConf,
 			s.path,

internal/core/source.go

@@ -7,7 +7,6 @@ import (
 	"github.com/bluenviron/gortsplib/v4/pkg/description"
 
 	"github.com/bluenviron/mediamtx/internal/defs"
-	"github.com/bluenviron/mediamtx/internal/externalcmd"
 	"github.com/bluenviron/mediamtx/internal/logger"
 )
 
@@ -48,45 +47,3 @@ func mediaInfo(medias []*description.Media) string {
 		}(),
 		strings.Join(mediasDescription(medias), ", "))
 }
-
-func sourceOnReadyHook(path *path) func() {
-	var env externalcmd.Environment
-	var onReadyCmd *externalcmd.Cmd
-
-	if path.conf.RunOnReady != "" {
-		env = path.externalCmdEnv()
-		desc := path.source.APISourceDescribe()
-		env["MTX_QUERY"] = path.publisherQuery
-		env["MTX_SOURCE_TYPE"] = desc.Type
-		env["MTX_SOURCE_ID"] = desc.ID
-	}
-
-	if path.conf.RunOnReady != "" {
-		path.Log(logger.Info, "runOnReady command started")
-		onReadyCmd = externalcmd.NewCmd(
-			path.externalCmdPool,
-			path.conf.RunOnReady,
-			path.conf.RunOnReadyRestart,
-			env,
-			func(err error) {
-				path.Log(logger.Info, "runOnReady command exited: %v", err)
-			})
-	}
-
-	return func() {
-		if onReadyCmd != nil {
-			onReadyCmd.Close()
-			path.Log(logger.Info, "runOnReady command stopped")
-		}
-
-		if path.conf.RunOnNotReady != "" {
-			path.Log(logger.Info, "runOnNotReady command launched")
-			externalcmd.NewCmd(
-				path.externalCmdPool,
-				path.conf.RunOnNotReady,
-				false,
-				env,
-				nil)
-		}
-	}
-}

internal/core/srt_conn.go

@@ -156,7 +156,7 @@ func (c *srtConn) run() { //nolint:dupl
 
 	desc := c.apiReaderDescribe()
 	c.conn.open(desc)
-	defer c.conn.close(desc)
+	defer c.conn.close()
 
 	err := c.runInner()
 
@@ -363,7 +363,7 @@ func (c *srtConn) runRead(req srtNewConnReq, pathName string, user string, pass
 
 	pathConf := res.path.safeConf()
 
-	onUnreadHook := readerOnReadHook(
+	onUnreadHook := onReadHook(
 		c.externalCmdPool,
 		pathConf,
 		res.path,

internal/core/webrtc_session.go

@@ -612,7 +612,7 @@ func (s *webRTCSession) runRead() (int, error) {
 
 	pathConf := res.path.safeConf()
 
-	onUnreadHook := readerOnReadHook(
+	onUnreadHook := onReadHook(
 		s.externalCmdPool,
 		pathConf,
 		res.path,

mediamtx.yml

@@ -471,7 +471,7 @@ pathDefaults:
   # Command to run when this path is requested by a reader
   # and no one is publishing to this path yet.
   # This can be used to publish a stream on demand.
-  # This is terminated with SIGINT when the path is not requested anymore.
+  # This is terminated with SIGINT when there are no readers anymore.
   # The following environment variables are available:
   # * MTX_PATH: path name
   # * MTX_QUERY: query parameters (passed by first reader)
@@ -487,6 +487,9 @@ pathDefaults:
   # The command will be closed when there are no
   # readers connected and this amount of time has passed.
   runOnDemandCloseAfter: 10s
+  # Command to run when there are no readers anymore.
+  # Environment variables are the same of runOnDemand.
+  runOnUnDemand:
 
   # Command to run when the stream is ready to be read, whenever it is
   # published by a client or pulled from a server / camera.