Add slate request handler

This change adds a request handler for /slate. This endpoint can
now be used to upload a new slate file.

cmd/vidforward/main.go

@@ -34,6 +34,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"os"
 	"strconv"
 	"sync"
 	"time"
@@ -217,6 +218,46 @@ func (m *broadcastManager) control(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// slate handles slate API requests to upload a new slate video.
+func (m *broadcastManager) slate(w http.ResponseWriter, r *http.Request) {
+	done := m.dogNotifier.handlerInvoked("slate")
+	defer done()
+
+	if r.Method != http.MethodPost {
+		http.Error(w, "invalid request method", http.StatusMethodNotAllowed)
+		return
+	}
+
+	file, _, err := r.FormFile("slate-file")
+	if err != nil {
+		m.errorLogWrite(m.log, w, "could not get slate file from form", "error", err)
+		return
+	}
+	defer file.Close()
+
+	// This will overwrite the slate file if it already exists.
+	dst, err := os.OpenFile(slateFileName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
+	if err != nil {
+		m.errorLogWrite(m.log, w, "could not open slate file", "error", err)
+		return
+	}
+	defer dst.Close()
+
+	n, err := io.Copy(dst, file)
+	if err != nil {
+		m.errorLogWrite(m.log, w, "could not copy slate file", "error", err)
+		return
+	}
+
+	// Return response to client as JSON.
+	jsn, err := json.Marshal(map[string]interface{}{"size": n})
+	if err != nil {
+		m.errorLogWrite(m.log, w, "could not get json for response", "error", err)
+		return
+	}
+	fmt.Fprint(w, string(jsn))
+}
+
 // processRequest unmarshals the broadcast data object from the request into
 // a Broadcast value, and then performs the provided action with that value.
 func (m *broadcastManager) processRequest(w http.ResponseWriter, r *http.Request, action func(Broadcast) error) {
@@ -374,6 +415,7 @@ func main() {
 
 	http.HandleFunc("/recv", m.recv)
 	http.HandleFunc("/control", m.control)
+	http.HandleFunc("/slate", m.slate)
 
 	go m.dogNotifier.notify()
 

cmd/vidforward/slate.go

@@ -36,6 +36,10 @@ import (
 	"bitbucket.org/ausocean/utils/logging"
 )
 
+// @note this is temporary; slate names will be created based on device mac so that we can
+// have a slate per device (or maybe multiple slates per device).
+const slateFileName = "/home/saxon/go/src/bitbucket.org/ausocean/av/cmd/vidforward/slate.h264"
+
 func writeSlateAndCheckErrors(dst io.Writer, signalCh chan struct{}, log logging.Logger) error {
 	// Also create an errCh that will be used to communicate errors from the
 	// writeSlate routine.
@@ -72,10 +76,6 @@ func writeSlateAndCheckErrors(dst io.Writer, signalCh chan struct{}, log logging
 func writeSlate(dst io.Writer, errCh chan error, exitSignal chan struct{}, log logging.Logger) {
 	log.Info("writing slate")
 	const (
-		// This is temporary and will eventually be part of a broadcast configuration
-		// where the remote vidforward API user can provide the slate image.
-		slateFileName = "/home/saxon/go/src/bitbucket.org/ausocean/av/cmd/vidforward/slate.h264"
-
 		// Assume 25fps until this becomes configurable.
 		slateFrameRate = 25