How to get ENV variable when doing Docker Inspect

Question

I wonder how I get an Environment variable from docker inspect.

when i run

docker inspect -f \"{{.Config.Env.PATH}} \" 1e2b8689cf06

Answer 1

docker inspect --format='{{range .Config.Env}}{{println .}}{{end}}' CONTAINER-NAME | grep -P "^YOUR_VAR=" | sed 's/[^=]*=//'

This solution requires grep(with -P option), sed and ability to pipeline them but solves 2 problems which most of the other solutions do not.

Firstly, it performs exact match on variable name. For example if you have following variables:

YOUR_VAR=value
ANOTHER_YOUR_VAR=value2
OTHER_VAR=YOUR_VAR

You will properly receive value.

Secondly, it properly handles cases where variable value contains = characters. For example:

REBEL_OPTS=-Drebel.stats=false

Will properly get you -Drebel.stats=false instead of false.