Hey SubstantialElk6 ,
You can see the bash script that installs the container https://github.com/allegroai/clearml-agent/blob/master/clearml_agent/glue/k8s.py#L61 .
You are correct that it does do apt-get update in order to install some stuff.
You can override this entire list of commands by adding another bash script as a string using the container_bash_script argument. Make sure you add it to the example script (should be added to the initialization https://github.com/allegroai/clearml-agent/blob/master/examples/k8s_glue_example.py#L75 ). You should also make sure you have all the other things installed and that clearml_agent is executed in the end of the bash script.