Nice shell in a Kubernetes pod

[henrebotha]

I sometimes have to run a shell inside a Kubernetes pod in order to debug things.

kubectl exec $pod -it -- bash

Unfortunately these in-pod shells are always extremely minimal, making even fundamental operations difficult if your fingers are used to things like alias l='ls -lAh'.

Worse, it turns out to be surprisingly difficult to e.g. pipe some shell config into this.

zsh-abbr turns out to be just the ticket. We can define a global abbreviation that will type out the verbose command needed to copy a ~/.kshellrc file into the pod and then run Bash sourcing that file.

abbr add -g '@kshell'='sh -c "echo '\''$(base64 -i ~/.kshellrc)'\'' | base64 -d > /tmp/.bashrc && exec bash --rcfile /tmp/.bashrc"'

(Linux users might need slightly different base64 arguments.)

Now I can do kubectl exec $pod -it -- @kshell to get a Bash instance with some useful predefined config.

(Aside: I'm very chuffed with the idea (not mine!) to use base 64 encoding to ensure that quotes etc are not messed with! I thought that was a super neat solution. Everything else I tried had issues with quoting.)

[olets]

Cool!