Adds echo source

cmd/echo/echo.go

@@ -0,0 +1,29 @@
+package echo
+
+import (
+	"bytes"
+	"github.com/AlexxIT/go2rtc/cmd/app"
+	"github.com/AlexxIT/go2rtc/cmd/streams"
+	"github.com/AlexxIT/go2rtc/pkg/shell"
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"os/exec"
+)
+
+func Init() {
+	log := app.GetLogger("echo")
+
+	streams.HandleFunc("echo", func(url string) (streamer.Producer, error) {
+		args := shell.QuoteSplit(url[5:])
+
+		b, err := exec.Command(args[0], args[1:]...).Output()
+		if err != nil {
+			return nil, err
+		}
+
+		b = bytes.TrimSpace(b)
+
+		log.Debug().Str("url", url).Msgf("[echo] %s", b)
+
+		return streams.GetProducer(string(b))
+	})
+}