Introduce Error Handling

This patch introduces basic error handling. This ensures that errors are
being logged and that the display reflects the error instead of just
showing an inactive state.

assets/index.js

@@ -11,25 +11,37 @@ fetch('/config')
 	setInterval(updateTimer, 2000);
 })
 
+/**
+ * Update the view
+ */
+function updateView(active) {
+	// Update text
+	document.getElementById('text').innerText = active.text;
+
+	// Update colors
+	const body = document.getElementsByTagName('body')[0];
+	body.style.backgroundColor = active.background;
+	body.style.color = active.color;
+
+	// Update logo
+	document.getElementById('logo').src = active.image.replace(/\s/g, '');
+}
+
 /**
  * Check for capture agent status
  */
 function updateTimer() {
 	fetch('/status')
-	.then(response => response.json())
-	.then(capturing => {
+	.then(response => {
+		if (!response.ok) {
+			const active = config.unknown;
+			active.text = response.statusText;
+			updateView(active);
+			throw Error(response.statusText);
+		}
+		return response.json()
+	}).then(capturing => {
 		console.debug('capturing', capturing)
-		const active = capturing ? config.capturing : config.idle;
-
-		// Update text
-		document.getElementById('text').innerText = active.text;
-
-		// Update colors
-		const body = document.getElementsByTagName('body')[0];
-		body.style.backgroundColor = active.background;
-		body.style.color = active.color;
-
-		// Update logo
-		document.getElementById('logo').src = active.image.replace(/\s/g, '');
+		updateView(capturing ? config.capturing : config.idle);
 	})
 }

main.go

@@ -57,6 +57,7 @@ type Config struct {
 	Display struct {
 		Capturing DisplayConfig `json:"capturing"`
 		Idle      DisplayConfig `json:"idle"`
+		Unknown   DisplayConfig `json:"unknown"`
 	}
 
 	Listen string
@@ -120,9 +121,15 @@ func setupRouter() *gin.Engine {
 		req.SetBasicAuth(config.Opencast.Username, config.Opencast.Password)
 		resp, err := client.Do(req)
 		if err != nil {
+			log.Println(err)
 			c.JSON(http.StatusBadGateway, nil)
 			return
 		}
+		if resp.StatusCode != 200 {
+			log.Println(resp)
+			c.JSON(resp.StatusCode, nil)
+			return
+		}
 		bodyText, err := ioutil.ReadAll(resp.Body)
 		s := string(bodyText)
 		var result AgentStateResult

opencast-ca-display.yml

@@ -110,6 +110,11 @@ display:
       bdf+Ja02rbN0Tm63v7bb1/63qhYAAAAAAAAAAAAAAAAAAAAAAAAAAIDY8w9T
       Gxe/25sMhQAAAABJRU5ErkJggg==
 
+  unknown:
+    text: Unknown
+    color: white
+    background: black
+
 
 # IP address and port to bind to
 listen: 127.0.0.1:8080