How to add umask to '/init'?

[donggrame]

I tried adding

RUN sed -i -e 's/exec s6-overlay/umask 000\nexec s6-overlay/' /init

and

$ docker run --rm -it test umask

shows 0022.

[skarnet]

You don't. s6-overlay fixes the default umask to 0022 for security reasons.

You can change it service by service or in your CMD with the umask shell or execline command. Try docker run --rm -it umask 000 test umask.