2025-04-20 11:27:17 +02:00

492 lines
15 KiB
Go

package mediaserver
import (
"bytes"
"cmp"
"context"
"crypto/rand"
"fmt"
"log/slog"
"net/http"
"os"
"time"
typescontainer "github.com/docker/docker/api/types/container"
"github.com/docker/go-connections/nat"
"gopkg.in/yaml.v3"
"git.netflux.io/rob/octoplex/internal/container"
"git.netflux.io/rob/octoplex/internal/domain"
)
// StreamKey is the stream key for the media server, which forms the RTMP path
// component and can be used as a basic form of authentication.
//
// It defaults to "live", in which case the full RTMP URL would be:
// `rtmp://localhost:1935/live`.
type StreamKey string
const (
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
defaultRTMPSPort = 1936 // default RTMPS host port for the media server
defaultHost = "localhost" // default mediaserver host name
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
configPath = "/mediamtx.yml" // path to the media server config file
tlsInternalCertPath = "/etc/tls-internal.crt" // path to the internal TLS cert
tlsInternalKeyPath = "/etc/tls-internal.key" // path to the internal TLS key
tlsCertPath = "/etc/tls.crt" // path to the custom TLS cert
tlsKeyPath = "/etc/tls.key" // path to the custom TLS key
)
// action is an action to be performed by the actor.
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
rtmpAddr domain.NetAddr
rtmpsAddr domain.NetAddr
apiPort int
host string
streamKey StreamKey
updateStateInterval time.Duration
pass string // password for the media server
keyPairInternal domain.KeyPair // TLS key pair for the media server
keyPairCustom domain.KeyPair // TLS key pair for the media server
logger *slog.Logger
apiClient *http.Client
// mutable state
state *domain.Source
}
// NewActorParams contains the parameters for building a new media server
// actor.
type NewActorParams struct {
RTMPAddr OptionalNetAddr // defaults to disabled, or 127.0.0.1:1935
RTMPSAddr OptionalNetAddr // defaults to disabled, or 127.0.0.1:1936
APIPort int // defaults to 9997
Host string // defaults to "localhost"
TLSCertPath string // defaults to empty
TLSKeyPath string // defaults to empty
StreamKey StreamKey // defaults to "live"
ChanSize int // defaults to 64
UpdateStateInterval time.Duration // defaults to 5 seconds
ContainerClient *container.Client
Logger *slog.Logger
}
// OptionalNetAddr is a wrapper around domain.NetAddr that indicates whether it
// is enabled or not.
type OptionalNetAddr struct {
domain.NetAddr
Enabled bool
}
// NewActor creates a new media server actor.
//
// Callers must consume the state channel exposed via [C].
func NewActor(ctx context.Context, params NewActorParams) (_ *Actor, err error) {
keyPairInternal, err := generateTLSCert()
if err != nil {
return nil, fmt.Errorf("generate TLS cert: %w", err)
}
var keyPairCustom domain.KeyPair
if params.TLSCertPath != "" {
keyPairCustom.Cert, err = os.ReadFile(params.TLSCertPath)
if err != nil {
return nil, fmt.Errorf("read TLS cert: %w", err)
}
keyPairCustom.Key, err = os.ReadFile(params.TLSKeyPath)
if err != nil {
return nil, fmt.Errorf("read TLS key: %w", err)
}
}
// TODO: custom cert for API?
apiClient, err := buildAPIClient(keyPairInternal.Cert)
if err != nil {
return nil, fmt.Errorf("build API client: %w", err)
}
chanSize := cmp.Or(params.ChanSize, defaultChanSize)
return &Actor{
rtmpAddr: toRTMPAddr(params.RTMPAddr, defaultRTMPPort),
rtmpsAddr: toRTMPAddr(params.RTMPSAddr, defaultRTMPSPort),
apiPort: cmp.Or(params.APIPort, defaultAPIPort),
host: cmp.Or(params.Host, defaultHost),
streamKey: cmp.Or(params.StreamKey, defaultStreamKey),
updateStateInterval: cmp.Or(params.UpdateStateInterval, defaultUpdateStateInterval),
keyPairInternal: keyPairInternal,
keyPairCustom: keyPairCustom,
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
}
func (a *Actor) Start(ctx context.Context) error {
var portSpecs []string
portSpecs = append(portSpecs, fmt.Sprintf("127.0.0.1:%d:9997", a.apiPort))
if !a.rtmpAddr.IsZero() {
portSpecs = append(portSpecs, fmt.Sprintf("%s:%d:%d", a.rtmpAddr.IP, a.rtmpAddr.Port, 1935))
}
if !a.rtmpsAddr.IsZero() {
portSpecs = append(portSpecs, fmt.Sprintf("%s:%d:%d", a.rtmpsAddr.IP, a.rtmpsAddr.Port, 1936))
}
exposedPorts, portBindings, err := nat.ParsePortSpecs(portSpecs)
if err != nil {
return fmt.Errorf("parse port specs: %w", err)
}
cfg, err := a.buildServerConfig()
if err != nil {
return fmt.Errorf("build server config: %w", err)
}
copyFiles := []container.CopyFileConfig{
{
Path: configPath,
Payload: bytes.NewReader(cfg),
Mode: 0600,
},
{
Path: tlsInternalCertPath,
Payload: bytes.NewReader(a.keyPairInternal.Cert),
Mode: 0600,
},
{
Path: tlsInternalKeyPath,
Payload: bytes.NewReader(a.keyPairInternal.Key),
Mode: 0600,
},
{
Path: "/etc/healthcheckopts.txt",
Payload: bytes.NewReader([]byte(fmt.Sprintf("--user api:%s", a.pass))),
Mode: 0600,
},
}
if !a.keyPairCustom.IsZero() {
copyFiles = append(
copyFiles,
container.CopyFileConfig{
Path: tlsCertPath,
Payload: bytes.NewReader(a.keyPairCustom.Cert),
Mode: 0600,
},
container.CopyFileConfig{
Path: tlsKeyPath,
Payload: bytes.NewReader(a.keyPairCustom.Key),
Mode: 0600,
},
)
}
args := []any{"host", a.host}
if a.rtmpAddr.IsZero() {
args = append(args, "rtmp.enabled", false)
} else {
args = append(args, "rtmp.enabled", true, "rtmp.bind_addr", a.rtmpAddr.IP, "rtmp.bind_port", a.rtmpAddr.Port)
}
if a.rtmpsAddr.IsZero() {
args = append(args, "rtmps.enabled", false)
} else {
args = append(args, "rtmps.enabled", true, "rtmps.bind_addr", a.rtmpsAddr.IP, "rtmps.bind_port", a.rtmpsAddr.Port)
}
a.logger.Info("Starting media server", args...)
containerStateC, errC := a.containerClient.RunContainer(
ctx,
container.RunContainerParams{
Name: componentName,
ChanSize: a.chanSize,
ContainerConfig: &typescontainer.Config{
Image: imageNameMediaMTX,
Hostname: "mediaserver",
Labels: map[string]string{container.LabelComponent: componentName},
Healthcheck: &typescontainer.HealthConfig{
Test: []string{
"CMD",
"curl",
"--fail",
"--silent",
"--cacert", "/etc/tls-internal.crt",
"--config", "/etc/healthcheckopts.txt",
a.healthCheckURL(),
},
Interval: time.Second * 10,
StartPeriod: time.Second * 2,
StartInterval: time.Second * 2,
Retries: 2,
},
ExposedPorts: exposedPorts,
},
HostConfig: &typescontainer.HostConfig{
NetworkMode: "default",
PortBindings: portBindings,
},
NetworkCountConfig: container.NetworkCountConfig{Rx: "eth0", Tx: "eth1"},
Logs: container.LogConfig{Stdout: true},
CopyFiles: copyFiles,
},
)
go a.actorLoop(ctx, containerStateC, errC)
return nil
}
func (a *Actor) buildServerConfig() ([]byte, error) {
// NOTE: Regardless of the user configuration (which mostly affects exposed
// ports and UI rendering) plain RTMP must be enabled at the container level,
// for internal connections.
var encryptionString string
if a.rtmpsAddr.IsZero() {
encryptionString = "no"
} else {
encryptionString = "optional"
}
var certPath, keyPath string
if a.keyPairCustom.IsZero() {
certPath = tlsInternalCertPath
keyPath = tlsInternalKeyPath
} else {
certPath = tlsCertPath
keyPath = tlsKeyPath
}
return yaml.Marshal(
Config{
LogLevel: "debug",
LogDestinations: []string{"stdout"},
AuthMethod: "internal",
AuthInternalUsers: []User{
{
User: "any",
IPs: []string{}, // any IP
Permissions: []UserPermission{
{Action: "publish"},
},
},
{
User: "api",
Pass: a.pass,
IPs: []string{}, // any IP
Permissions: []UserPermission{
{Action: "read"},
},
},
{
User: "api",
Pass: a.pass,
IPs: []string{}, // any IP
Permissions: []UserPermission{{Action: "api"}},
},
},
RTMP: true,
RTMPEncryption: encryptionString,
RTMPAddress: ":1935",
RTMPSAddress: ":1936",
RTMPServerCert: certPath,
RTMPServerKey: keyPath,
API: true,
APIEncryption: true,
APIServerCert: tlsInternalCertPath,
APIServerKey: tlsInternalKeyPath,
Paths: map[string]Path{
string(a.streamKey): {Source: "publisher"},
},
},
)
}
// C returns a channel that will receive the current state of the media server.
func (s *Actor) C() <-chan domain.Source {
return s.stateC
}
// State returns the current state of the media server.
//
// Blocks if the actor is not started yet.
func (s *Actor) State() domain.Source {
resultChan := make(chan domain.Source)
s.actorC <- func() {
resultChan <- *s.state
}
return <-resultChan
}
// Close closes the media server actor.
func (s *Actor) Close() error {
if err := s.containerClient.RemoveContainers(
context.Background(),
s.containerClient.ContainersWithLabels(map[string]string{container.LabelComponent: componentName}),
); err != nil {
return fmt.Errorf("remove containers: %w", err)
}
return nil
}
// 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) {
updateStateT := time.NewTicker(s.updateStateInterval)
defer updateStateT.Stop()
sendState := func() { s.stateC <- *s.state }
for {
select {
case containerState := <-containerStateC:
s.state.Container = containerState
if s.state.Container.Status == domain.ContainerStatusExited {
updateStateT.Stop()
s.handleContainerExit(nil)
}
sendState()
continue
case err, ok := <-errC:
if !ok {
// The loop continues until the actor is closed.
// Avoid receiving duplicate close signals.
errC = nil
continue
}
if err != nil {
s.logger.Error("Error from container client", "err", err, "id", shortID(s.state.Container.ID))
}
updateStateT.Stop()
s.handleContainerExit(err)
sendState()
case <-updateStateT.C:
path, err := fetchPath(s.pathURL(string(s.streamKey)), s.apiClient)
if err != nil {
s.logger.Error("Error fetching path", "err", err)
continue
}
if path.Ready != s.state.Live {
s.state.Live = path.Ready
s.state.LiveChangedAt = time.Now()
s.state.Tracks = path.Tracks
sendState()
}
case action, ok := <-s.actorC:
if !ok {
continue
}
action()
case <-ctx.Done():
return
}
}
}
// TODO: refactor to use container.Err?
func (s *Actor) handleContainerExit(err error) {
if s.state.Container.ExitCode != nil {
s.state.ExitReason = fmt.Sprintf("Server process exited with code %d.", *s.state.Container.ExitCode)
} else {
s.state.ExitReason = "Server process exited unexpectedly."
}
if err != nil {
s.state.ExitReason += "\n\n" + err.Error()
}
s.state.Live = false
}
// RTMPURL returns the RTMP URL for the media server, accessible from the host.
func (s *Actor) RTMPURL() string {
if s.rtmpAddr.IsZero() {
return ""
}
return fmt.Sprintf("rtmp://%s:%d/%s", s.host, s.rtmpAddr.Port, s.streamKey)
}
// RTMPSURL returns the RTMPS URL for the media server, accessible from the host.
func (s *Actor) RTMPSURL() string {
if s.rtmpsAddr.IsZero() {
return ""
}
return fmt.Sprintf("rtmps://%s:%d/%s", s.host, s.rtmpsAddr.Port, s.streamKey)
}
// RTMPInternalURL returns the RTMP URL for the media server, accessible from
// the app network.
func (s *Actor) RTMPInternalURL() string {
// Container port, not host port:
return fmt.Sprintf("rtmp://mediaserver:1935/%s?user=api&pass=%s", s.streamKey, s.pass)
}
// 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
// container. It is logged to Docker's events log so must not include
// credentials.
func (s *Actor) healthCheckURL() string {
return fmt.Sprintf("https://localhost:%d/v3/paths/list", s.apiPort)
}
// shortID returns the first 12 characters of the given container ID.
func shortID(id string) string {
if len(id) < 12 {
return id
}
return id[:12]
}
// generatePassword securely generates a random password suitable for
// authenticating media server endpoints.
func generatePassword() string {
const lenBytes = 32
p := make([]byte, lenBytes)
_, _ = rand.Read(p)
return fmt.Sprintf("%x", []byte(p))
}
// toRTMPAddr builds a domain.NetAddr from an OptionalNetAddr, with default
// values set to RTMP default bind config if needed. If the OptionalNetAddr is
// not enabled, a zero value is returned.
func toRTMPAddr(a OptionalNetAddr, defaultPort int) domain.NetAddr {
if !a.Enabled {
return domain.NetAddr{}
}
return domain.NetAddr{
IP: cmp.Or(a.IP, defaultRTMPIP),
Port: cmp.Or(a.Port, defaultPort),
}
}