Not able to access env variables in kubernetes pod-CodePudding

In my pod I have some env variables. I have written a bash script to get inside the pod and connect to database using the env variables. But am not able to use the env variables.

kubectl exec $POD_ID  -- /bin/bash -c """
     printenv DATABASE_HOST_NAME
     echo $DATABASE_HOST_NAME
     psql -h $DATABASE_HOST_NAME -U DATABASE_USER
"""

Here printenv returns the correct env variable value. echo returns empty. And psql statement doesn't take the host. Anyone has any idea how i can use the env variables in the pod in my psql connection statement.

When i manually get in the container and run the psql command with env variable it works file.But when running the script it shows the error.

CodePudding user response：

You can try this as a workaround:

psql -h $(printenv DATABASE_HOST_NAME)

However, this can help: https://www.reddit.com/r/linuxquestions/comments/e2x2xv/differences_between_printenv_and_echo/&ved=2ahUKEwiCwZ3vkMD3AhX_jokEHSKLCAgQjjh6BAgHEAE&usg=AOvVaw2zSOnGM16E76x8u70_9vVT

CodePudding user response：

You can check this post I answered days ago: Can't access postgres via service from the postgres container itself

With this configuration I am able to access the env variable I have configured.

bguess

CodePudding user response：

As DATABASE_HOST_NAME is defined in k8s pod, you need single quote to avoid $DATABASE_HOST_NAME to be expanded on the host.

kubectl exec $POD_ID  -- /bin/bash -c '
     printenv DATABASE_HOST_NAME
     echo $DATABASE_HOST_NAME
     psql -h $DATABASE_HOST_NAME -U DATABASE_USER
'