The default shell in Alpine Linux is ash.
Ash will only read the /etc/profile and ~/.profile files if it is started as a login shell sh -l.
To force Ash to source the /etc/profile or any other script you want upon its invocation as a non login shell, you need to setup an environment variable called ENV before launching Ash.
Editor’s note: ENV is only sourced if the shell is interactive.
e.g. in your Dockerfile
FROM alpine:3.5
ENV ENV="/root/.ashrc"
RUN echo "echo 'Hello, world!'" > "$ENV"
When you build that you get:
deployer@ubuntu-1604-amd64:~/blah$ docker build --tag test .
Sending build context to Docker daemon 2.048kB
Step 1/3 : FROM alpine:3.5
3.5: Pulling from library/alpine
627beaf3eaaf: Pull complete
Digest: sha256:58e1a1bb75db1b5a24a462dd5e2915277ea06438c3f105138f97eb53149673c4
Status: Downloaded newer image for alpine:3.5
---> 4a415e366388
Step 2/3 : ENV ENV "/root/.ashrc"
---> Running in a9b6ff7303c2
---> 8d4af0b7839d
Removing intermediate container a9b6ff7303c2
Step 3/3 : RUN echo "echo 'Hello, world!'" > "$ENV"
---> Running in 57c2fd3353f3
---> 2cee6e034546
Removing intermediate container 57c2fd3353f3
Successfully built 2cee6e034546
Finally, when you run the newly generated container, you get:
deployer@ubuntu-1604-amd64:~/blah$ docker run -ti test /bin/sh
Hello, world!
/ # exit
Notice the Ash shell didn’t run as a login shell.
So to answer your query, replace
ENV ENV="/root/.ashrc"
with:
ENV ENV="/etc/profile"
and Alpine Linux’s Ash shell will automatically source the /etc/profile script each time the shell is launched.
Gotcha: /etc/profile is normally meant to only be sourced once! So, I would advise that you don’t source it and instead source a /root/.somercfile instead.
Source: https://stackoverflow.com/a/40538356