Debugging packer builds.

It can be useful to debug what's going on in the packer build.

You can push to a branch and then run the packer build on your branch with debug output which will ask before each operation and also let you ssh into the remote machine. Once the Step "Wating for instance to be ready" is reached you can ssh into the machine and debug what's going on.

Run the packer with something like like:

git:mg/gpu $ git commit -am "WIP" && \
  git push -u && \
  make packer-gpu-node EXTRA_ARGS="-debug -var BRANCH='mg/gpu'"

Then you can ssh with

git:mg/gpu $ ssh -i ec2_jammy.pem ubuntu@44.202.28.62

where 44.202.28.62 is the "Public IP" of the instance.

Debugging CE on the remote packer instance

If you want to test out CE running on the in-progress packer image, once the install is done but before it shuts down, log in with something like:

git:mg/gpu $ ssh -i ec2_jammy.pem ubuntu@44.202.28.62 -L10240:127.0.0.1:10240
44.202.28.62: $ sudo service compiler-explorer start

that is, forward local port 10240 to the remote port, and then start the service. You can then play around with the remote CE on localhost:10240

To make it run in a different environment, you'll need to hack the /infra/start-support.sh to override the ENV it picks up from AWS node config. Edit the ENV directly, and then restart the service.