How can I access Docker set Environment Variables From a Cron Job

Question

I\'ve recently tried running a cron job from within a linked docker container and run into an issue. My main docker container is linked to a postgres container and its port numb

Answer 1

You can run the following command

. <(xargs -0 bash -c 'printf "export %q\n" "$@"' -- < /proc/1/environ)

This is exceptionally works when you have the environment variables with special characters like ' " =

Answer 2

I would recommend using declare to export your environment and avoid escaping issues (use CMD or ENTRYPOINT or directly in a wrapper script which might be called by one of them):

declare -p | grep -Ev 'BASHOPTS|BASH_VERSINFO|EUID|PPID|SHELLOPTS|UID' > /container.env

Grep -v takes care of filtering out read-only variables.

You can later easily load this environment like this:

SHELL=/bin/bash
BASH_ENV=/container.env
* * * * * root /test-cron.sh