switched rover <-> server streams to rtsptcp, and moved mediamtx to be a server owned and configured child process!

pi/roverd/config.go

@@ -3,9 +3,11 @@ package roverd
 import (
 	"errors"
 	"fmt"
+	"net"
 	"net/url"
 	"os"
 	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -77,10 +79,10 @@ type HornConfig struct {
 }
 
 type MediaConfig struct {
-	// PublishPort is shared by the derived video, microphone, and forwarded-audio
-	// SRT URLs. Keeping it at this level prevents each nested block from needing
+	// RTSPPort is shared by the derived video, microphone, and forwarded-audio
+	// RTSP URLs. Keeping it at this level prevents each nested block from needing
 	// to repeat the same server port when the common MediaMTX listener is used.
-	PublishPort    int                 `yaml:"publishPort" json:"-"`
+	RTSPPort       int                 `yaml:"rtspPort" json:"-"`
 	Manage         bool                `yaml:"manage" json:"manage"`
 	HealthURL      string              `yaml:"healthUrl" json:"healthUrl,omitempty"`
 	HealthInterval Duration            `yaml:"healthInterval" json:"-"`
@@ -93,10 +95,12 @@ type VideoMediaConfig struct {
 	// Publisher selects the installed publisher script/pipeline family. The
 	// first pass uses pi-libcamera for current rovers; laptop-v4l2 can be added
 	// without changing the server-facing media shape again.
-	Enabled     bool   `yaml:"enabled" json:"enabled"`
-	Service     string `yaml:"service" json:"service,omitempty"`
-	Publisher   string `yaml:"publisher" json:"publisher,omitempty"`
-	PublishURL  string `yaml:"publishUrl" json:"publishUrl,omitempty"`
+	Enabled   bool   `yaml:"enabled" json:"enabled"`
+	Service   string `yaml:"service" json:"service,omitempty"`
+	Publisher string `yaml:"publisher" json:"publisher,omitempty"`
+	// PublishURL is derived during validation. It remains in rover metadata for server-side
+	// consumers, but is not a second hand-written endpoint in /etc/roverd.yaml.
+	PublishURL  string `yaml:"-" json:"publishUrl,omitempty"`
 	Device      string `yaml:"device" json:"device,omitempty"`
 	InputFormat string `yaml:"inputFormat" json:"-"`
 	Width       int    `yaml:"width" json:"-"`
@@ -111,9 +115,10 @@ type AudioCaptureConfig struct {
 	// AudioCapture describes the rover microphone stream that browsers can
 	// subscribe to as "<rover>-audio". A disabled capture block still has
 	// normalized defaults so enabling it only requires flipping enabled: true.
-	Enabled    bool   `yaml:"enabled" json:"enabled"`
-	Service    string `yaml:"service" json:"service,omitempty"`
-	PublishURL string `yaml:"publishUrl" json:"publishUrl,omitempty"`
+	Enabled bool   `yaml:"enabled" json:"enabled"`
+	Service string `yaml:"service" json:"service,omitempty"`
+	// PublishURL follows the same derived-only contract as the video path.
+	PublishURL string `yaml:"-" json:"publishUrl,omitempty"`
 	Device     string `yaml:"device" json:"device,omitempty"`
 	SampleRate int    `yaml:"sampleRate" json:"-"`
 	Channels   int    `yaml:"channels" json:"-"`
@@ -125,9 +130,10 @@ type AudioPlaybackConfig struct {
 	// MediaMTX for playback on the rover speaker. The URL is a request/read URL
 	// for the rover listener, while the server converts it to publish mode when
 	// it needs to inject audio.
-	Enabled         bool   `yaml:"enabled" json:"enabled"`
-	Service         string `yaml:"service" json:"service,omitempty"`
-	ForwardURL      string `yaml:"forwardUrl" json:"forwardUrl,omitempty"`
+	Enabled bool   `yaml:"enabled" json:"enabled"`
+	Service string `yaml:"service" json:"service,omitempty"`
+	// ForwardURL is derived because the server and rover must agree on the exact -fwd path.
+	ForwardURL      string `yaml:"-" json:"forwardUrl,omitempty"`
 	Device          string `yaml:"device" json:"device,omitempty"`
 	Normalize       bool   `yaml:"normalize" json:"-"`
 	NormalizeFilter string `yaml:"normalizeFilter" json:"-"`
@@ -230,7 +236,7 @@ func LoadConfig(path string) (*Config, error) {
 			},
 		},
 		Media: MediaConfig{
-			PublishPort:    9000,
+			RTSPPort:       8554,
 			HealthInterval: Duration{Duration: 30 * time.Second},
 			Video: VideoMediaConfig{
 				Enabled:    true,
@@ -349,8 +355,8 @@ func LoadConfig(path string) (*Config, error) {
 	if cfg.BRC.GPIOChip == "" {
 		cfg.BRC.GPIOChip = "gpiochip0"
 	}
-	if cfg.Media.PublishPort <= 0 {
-		cfg.Media.PublishPort = 9000
+	if cfg.Media.RTSPPort <= 0 {
+		cfg.Media.RTSPPort = 8554
 	}
 	if err := validateMediaConfig(&cfg.Media, cfg.ServerURL, cfg.Name); err != nil {
 		return nil, fmt.Errorf("media: %w", err)
@@ -432,25 +438,25 @@ func validateMediaConfig(cfg *MediaConfig, serverURL string, roverName string) e
 		file is written. This keeps the Pi behavior stable while making laptop
 		and future publisher variants explicit configuration choices.
 	*/
-	if cfg.PublishPort <= 0 {
-		cfg.PublishPort = 9000
+	if cfg.RTSPPort <= 0 {
+		cfg.RTSPPort = 8554
 	}
 	if cfg.HealthInterval.Duration <= 0 {
 		cfg.HealthInterval = Duration{Duration: 30 * time.Second}
 	}
-	if err := validateVideoMediaConfig(&cfg.Video, serverURL, roverName, cfg.PublishPort); err != nil {
+	if err := validateVideoMediaConfig(&cfg.Video, serverURL, roverName, cfg.RTSPPort); err != nil {
 		return fmt.Errorf("video: %w", err)
 	}
-	if err := validateAudioCaptureConfig(&cfg.AudioCapture, serverURL, roverName, cfg.PublishPort); err != nil {
+	if err := validateAudioCaptureConfig(&cfg.AudioCapture, serverURL, roverName, cfg.RTSPPort); err != nil {
 		return fmt.Errorf("audioCapture: %w", err)
 	}
-	if err := validateAudioPlaybackConfig(&cfg.AudioPlayback, serverURL, roverName, cfg.PublishPort); err != nil {
+	if err := validateAudioPlaybackConfig(&cfg.AudioPlayback, serverURL, roverName, cfg.RTSPPort); err != nil {
 		return fmt.Errorf("audioPlayback: %w", err)
 	}
 	return nil
 }
 
-func validateVideoMediaConfig(cfg *VideoMediaConfig, serverURL string, roverName string, publishPort int) error {
+func validateVideoMediaConfig(cfg *VideoMediaConfig, serverURL string, roverName string, rtspPort int) error {
 	if cfg.Service == "" {
 		cfg.Service = "video-publisher.service"
 	}
@@ -476,17 +482,19 @@ func validateVideoMediaConfig(cfg *VideoMediaConfig, serverURL string, roverName
 	if cfg.SensorMode == "" && cfg.Publisher == "pi-libcamera" {
 		cfg.SensorMode = "1296:972"
 	}
-	if cfg.PublishURL == "" {
-		derived, err := derivePublishURL(serverURL, roverName, publishPort)
-		if err != nil {
-			return fmt.Errorf("derive publishUrl: %w", err)
-		}
-		cfg.PublishURL = derived
+	/*
+		Always derive this endpoint. Older rover configs can contain an explicit SRT publishUrl;
+		honoring it after a binary update would silently leave that rover on the old transport.
+	*/
+	derived, err := derivePublishURL(serverURL, roverName, rtspPort)
+	if err != nil {
+		return fmt.Errorf("derive publishUrl: %w", err)
 	}
+	cfg.PublishURL = derived
 	return nil
 }
 
-func validateAudioCaptureConfig(cfg *AudioCaptureConfig, serverURL string, roverName string, publishPort int) error {
+func validateAudioCaptureConfig(cfg *AudioCaptureConfig, serverURL string, roverName string, rtspPort int) error {
 	if cfg.Service == "" {
 		cfg.Service = "audio-only-publisher.service"
 	}
@@ -502,17 +510,15 @@ func validateAudioCaptureConfig(cfg *AudioCaptureConfig, serverURL string, rover
 	if cfg.Bitrate <= 0 {
 		cfg.Bitrate = 510000
 	}
-	if cfg.PublishURL == "" {
-		derived, err := derivePublishURL(serverURL, roverName+"-audio", publishPort)
-		if err != nil {
-			return fmt.Errorf("derive publishUrl: %w", err)
-		}
-		cfg.PublishURL = derived
+	derived, err := derivePublishURL(serverURL, roverName+"-audio", rtspPort)
+	if err != nil {
+		return fmt.Errorf("derive publishUrl: %w", err)
 	}
+	cfg.PublishURL = derived
 	return nil
 }
 
-func validateAudioPlaybackConfig(cfg *AudioPlaybackConfig, serverURL string, roverName string, publishPort int) error {
+func validateAudioPlaybackConfig(cfg *AudioPlaybackConfig, serverURL string, roverName string, rtspPort int) error {
 	if cfg.Service == "" {
 		cfg.Service = "audio-forward-listener.service"
 	}
@@ -522,13 +528,11 @@ func validateAudioPlaybackConfig(cfg *AudioPlaybackConfig, serverURL string, rov
 	if cfg.NormalizeFilter == "" {
 		cfg.NormalizeFilter = "dynaudnorm=f=75:g=15:m=10:p=0.9,alimiter=limit=0.85:level=disabled"
 	}
-	if cfg.ForwardURL == "" {
-		derived, err := deriveReadURL(serverURL, roverName+"-fwd", publishPort)
-		if err != nil {
-			return fmt.Errorf("derive forwardUrl: %w", err)
-		}
-		cfg.ForwardURL = derived
+	derived, err := deriveReadURL(serverURL, roverName+"-fwd", rtspPort)
+	if err != nil {
+		return fmt.Errorf("derive forwardUrl: %w", err)
 	}
+	cfg.ForwardURL = derived
 	return nil
 }
 
@@ -577,20 +581,17 @@ func validateAutoSideBrushConfig(cfg *AutoSideBrushConfig) {
 }
 
 func derivePublishURL(serverURL, streamName string, port int) (string, error) {
-	return deriveSRTURL(serverURL, streamName, port, "publish")
+	return deriveRTSPURL(serverURL, streamName, port)
 }
 
 func deriveReadURL(serverURL, streamName string, port int) (string, error) {
-	return deriveSRTURL(serverURL, streamName, port, "request")
+	return deriveRTSPURL(serverURL, streamName, port)
 }
 
-func deriveSRTURL(serverURL, streamName string, port int, mode string) (string, error) {
+func deriveRTSPURL(serverURL, streamName string, port int) (string, error) {
 	if streamName == "" {
 		return "", errors.New("missing stream name for publishUrl")
 	}
-	if mode == "" {
-		mode = "publish"
-	}
 	parsed, err := url.Parse(serverURL)
 	if err != nil {
 		return "", err
@@ -600,10 +601,16 @@ func deriveSRTURL(serverURL, streamName string, port int, mode string) (string,
 		return "", errors.New("serverUrl missing host")
 	}
 	if port <= 0 {
-		port = 9000
+		port = 8554
 	}
+	/*
+		JoinHostPort handles both ordinary hostnames and bracketed IPv6 addresses. The rover name
+		is a MediaMTX path, so it is escaped independently instead of interpolated into the host.
+		RTSP distinguishes publishing from reading through protocol methods, which is why both
+		directions intentionally use the same URL shape.
+	*/
 	escaped := url.PathEscape(streamName)
-	return fmt.Sprintf("srt://%s:%d?streamid=#!::r=%s,m=%s&latency=10&mode=caller&transtype=live&pkt_size=1316", host, port, escaped, mode), nil
+	return fmt.Sprintf("rtsp://%s/%s", net.JoinHostPort(host, strconv.Itoa(port)), escaped), nil
 }
 
 var hexColorRe = regexp.MustCompile(`^#[0-9A-Fa-f]{6}$`)

pi/roverd/media_url_test.go

@@ -0,0 +1,80 @@
+package roverd
+
+// These tests pin the network-agnostic RTSP contract. A rover provides its server URL and name
+// once; all three media paths must then resolve to distinct, safely escaped MediaMTX paths.
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestMediaURLsDeriveFromServerURLAndRoverName(t *testing.T) {
+	cfg := MediaConfig{
+		Video:         VideoMediaConfig{Enabled: true},
+		AudioCapture:  AudioCaptureConfig{Enabled: true},
+		AudioPlayback: AudioPlaybackConfig{Enabled: true},
+	}
+	if err := validateMediaConfig(&cfg, "ws://control-server.local:8080/rover", "rover one"); err != nil {
+		t.Fatalf("validate media config: %v", err)
+	}
+
+	wants := map[string]string{
+		"video":   "rtsp://control-server.local:8554/rover%20one",
+		"mic":     "rtsp://control-server.local:8554/rover%20one-audio",
+		"speaker": "rtsp://control-server.local:8554/rover%20one-fwd",
+	}
+	got := map[string]string{
+		"video":   cfg.Video.PublishURL,
+		"mic":     cfg.AudioCapture.PublishURL,
+		"speaker": cfg.AudioPlayback.ForwardURL,
+	}
+	for name, want := range wants {
+		if got[name] != want {
+			t.Errorf("%s URL: got %q, want %q", name, got[name], want)
+		}
+	}
+	if cfg.RTSPPort != 8554 {
+		t.Fatalf("RTSP port: got %d, want 8554", cfg.RTSPPort)
+	}
+}
+
+func TestExplicitMediaPortAppliesToEveryRTSPPath(t *testing.T) {
+	cfg := MediaConfig{
+		RTSPPort:      10554,
+		Video:         VideoMediaConfig{Enabled: true},
+		AudioCapture:  AudioCaptureConfig{Enabled: true},
+		AudioPlayback: AudioPlaybackConfig{Enabled: true},
+	}
+	if err := validateMediaConfig(&cfg, "ws://media.example/rover", "r1"); err != nil {
+		t.Fatalf("validate media config: %v", err)
+	}
+	for name, value := range map[string]string{
+		"video": cfg.Video.PublishURL, "mic": cfg.AudioCapture.PublishURL, "speaker": cfg.AudioPlayback.ForwardURL,
+	} {
+		if !strings.Contains(value, ":10554/") {
+			t.Errorf("%s URL did not use configured port: %q", name, value)
+		}
+	}
+}
+
+func TestLegacyExplicitSRTURLsCannotKeepAnUpdatedRoverOnTheOldTransport(t *testing.T) {
+	/*
+		Deployed rover configs can still contain these former fields. Validation must replace
+		them unconditionally so updating roverd is sufficient to move the whole media path.
+	*/
+	cfg := MediaConfig{
+		Video:         VideoMediaConfig{Enabled: true, PublishURL: "srt://old/video"},
+		AudioCapture:  AudioCaptureConfig{Enabled: true, PublishURL: "srt://old/audio"},
+		AudioPlayback: AudioPlaybackConfig{Enabled: true, ForwardURL: "srt://old/forward"},
+	}
+	if err := validateMediaConfig(&cfg, "ws://new-server.local:8080/rover", "r1"); err != nil {
+		t.Fatalf("validate media config: %v", err)
+	}
+	for name, value := range map[string]string{
+		"video": cfg.Video.PublishURL, "mic": cfg.AudioCapture.PublishURL, "speaker": cfg.AudioPlayback.ForwardURL,
+	} {
+		if !strings.HasPrefix(value, "rtsp://new-server.local:8554/") {
+			t.Errorf("%s retained an old transport URL: %q", name, value)
+		}
+	}
+}

pi/roverd/roverd.debian-laptop.sample.yaml

@@ -22,7 +22,8 @@ battery:
 maxWheelSpeed: 350
 
 media:
-  publishPort: 9000
+  # Media URLs are derived from serverUrl's hostname, this port, and the rover name.
+  rtspPort: 8554
   manage: true
   healthUrl: ""
   healthInterval: 30s

pi/roverd/roverd.sample.yaml

@@ -17,7 +17,8 @@ battery:
   urgent: 1650
 maxWheelSpeed: 350
 media:
-  publishPort: 9000
+  # Media URLs are derived from serverUrl's hostname, this port, and the rover name.
+  rtspPort: 8554
   manage: true
   healthUrl: ""
   healthInterval: 30s
@@ -25,7 +26,6 @@ media:
     enabled: true
     service: video-publisher.service
     publisher: pi-libcamera
-    publishUrl: srt://192.168.0.86:9000?streamid=#!::r=roomba-alpha,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316
     width: 640
     height: 480
     fps: 30
@@ -36,7 +36,6 @@ media:
   audioCapture:
     enabled: false
     service: audio-only-publisher.service
-    publishUrl: srt://192.168.0.86:9000?streamid=#!::r=roomba-alpha-audio,m=publish&latency=10&mode=caller&transtype=live&pkt_size=1316
     device: hw:0,0
     sampleRate: 48000
     channels: 2
@@ -44,7 +43,6 @@ media:
   audioPlayback:
     enabled: true
     service: audio-forward-listener.service
-    forwardUrl: srt://192.168.0.86:9000?streamid=#!::r=roomba-alpha-fwd,m=request&latency=10&mode=caller&transtype=live&pkt_size=1316
     device: forward
     normalize: true
 cameraServo: