I have a container running on Kubernetes where I would like to run a command from my local terminal. The working directory of the container based on its yaml file is at say /opt/gopath/src/a/. However, I would like to run the command at directory /opt/gopath/src/b/. Additionally, I also need to set certain temporary environment variables before running this command. So currently, this is what I am doing:
kubectl exec $pod_name -- bash -c "cd ../b/; env ENV_VARIABLE_1=ENV_VALUE_2 && env ENV_VARIABLE_2=ENV_VALUE_2 && <cmd to run>".
This seems to be working currently. However, I am not convinced that this is the best way to achieve this. Also, running this command displays all the environment variables in the container -- which I would like not to be printed if possible. Could anyone point me in the right direction?
In case of static variables, I would suggest using Config maps.
Since you need to use temporary variables from a local shell, there is no need to use long and complicated commands as exec connects your terminal to the running Container (pod). I tested your issue and created a simple environment variable on the local system. I used syntax provided by you:
kubectl exec -it $pod_name -- sh -c 'key=123 key2=121; echo "$key $key2"'To pass env vars, you can just set it like that and add delimiter ';' between variables and your command.
This is very late but I'm sure it will be very helpful.
envsubst solves this issue in a one-liner.
The below command replaces env variables in YAML file with actual values.
cat <filename>.yaml | envsubst | kubectl apply -f -bash -c "cd ../b/; env ENV_VARIABLE_1=ENV_VALUE_2 ENV_VARIABLE_2=ENV_VALUE_2 <cmd to run>"
i would suggest specifying the details (including env variables) in a manifest .yaml file and then doing kubectl create -f manifest.yaml
This is much more reproducible than having a ton of flags in the command line.