Modify the startup script to fix a package installation error

tailbone/compute_engine/__init__.py

@@ -55,6 +55,8 @@
 
 STARTUP_SCRIPT_BASE = """#!/bin/bash
 
+export DEBIAN_FRONTEND=noninteractive
+
 # update open files limit
 ulimit -n 10000
 

tailbone/turn/__init__.py

@@ -63,6 +63,13 @@ class TailboneTurnInstance(TailboneCEInstance):
 while true
 do
   turnserver --use-auth-secret -v -a -X $IP -f --static-auth-secret %s -r %s
+
+  # Sometimes the packages fail to install due to no public key error.
+  aptitude install -y debian-keyring debian-archive-keyring
+  apt-get update
+  dpkg -i rfc5766-turn-server_3.2.3.6-1_amd64.deb
+  apt-get -fy install
+
   sleep 1
 done