Docker Google cloud

Question

I have a CentOS VM instance in google cloud and I have installed docker on CentOS. I have created a container with web interface. I am not able to access it When i try to access it from outside (In browser Other tab). What do I need to do to access it from outside of cloud?

Answer 1

There are several leaps between your browser your containerised web interface.

The first will be from the IP through the GCP firewall into the Instance, you might be getting stuck here, when you created the instance, in the Firewall section, did you select "Allow HTTP traffic and Allow HTTPS traffic"?

If you click through to your instance details in the GCP dashboard you can see under Firewalls if this is selected, also if you look under Network you can see which network profile your instance it using, you can click the network listed to check if it is set up to allow the traffic you are trying to send though.

If this all looks right and traffic is getting to the instance but not the web interface, it could be that the port from docker is not mapped to the port of the host, when you started the container did you use the -p option to map the ports?

If this is also right, then it could be that the Docker image is not exposing it's port internally, in the Dockerfile used to create the Image for the container is there a line starting with EXPOSE , or does if build FROM an Image that does?

There are more possible points of failure in this chain but I have tried to list some likely answers. If none of this helps then let me know in the comments and we can try and debug the issue.