Debug a Google Cloud VM Machine

Can't access app deployed with docker and google cloud

First, test to see if your service works at all. To do this, from the VM itself, run:

wget http://localhost:32768

or

curl http://localhost:32768

If that works, that means the service is operating properly, so let's move further with the debugging.

There may be two firewalls that are blocking external access to your docker process:

1. the VM's OS firewall
2. Google Compute Engine firewall

You can see if you're affected by the first issue by accessing the URL from the VM itself and from another VM on the same GCE network (use the VM name in the URL, not the external IP):

wget http://[vm-name]:32768

To fix the first issue, you would have to either open up the single port (recommended):

iptables -I INPUT -p tcp -s 0.0.0.0/0 --dport 32768 -j ACCEPT

or disable firewall entirely, e.g., by stopping iptables (not recommended).

If, after fixing this, you can access the URL from another host on the same GCE network, but still can't access it from outside of Google Compute Engine, you're affected by the second issue. To fix it, you will need to open the port in the GCE firewall; this can also be done via the web UI in the Developers Console.