The screen websocket now sends ping messages every now and then, so that it won't get caught by nginx's proxy_read_timeout if the screen is off or not moving. Previously, nginx may have decided to kill the connection after a period of no activity.

lib/cli/device/index.js

@@ -85,6 +85,12 @@ module.exports.builder = function(yargs) {
     , type: 'number'
     , default: process.env.SCREEN_JPEG_QUALITY || 80
     })
+    .option('screen-ping-interval', {
+      describe: 'The interval at which to send ping messages to keep the ' +
+        'screen WebSocket alive.'
+    , type: 'number'
+    , default: 30000
+    })
     .option('screen-port', {
       describe: 'Port allocated to the screen WebSocket.'
     , type: 'number'
@@ -129,9 +135,10 @@ module.exports.handler = function(argv) {
   , storageUrl: argv.storageUrl
   , adbHost: argv.adbHost
   , adbPort: argv.adbPort
-  , screenWsUrlPattern: argv.screenWsUrlPattern
   , screenJpegQuality: argv.screenJpegQuality
+  , screenPingInterval: argv.screenPingInterval
   , screenPort: argv.screenPort
+  , screenWsUrlPattern: argv.screenWsUrlPattern
   , connectUrlPattern: argv.connectUrlPattern
   , connectPort: argv.connectPort
   , vncPort: argv.vncPort