Merge ~sergiodj/ubuntu-docker-images/+git/bind9:bind9-user into ~ubuntu-docker-images/ubuntu-docker-images/+git/bind9:9.18-22.04

[Sergio Durigan Junior]

This MP improves bind9's entrypoint script to allow the specification of a user that will own the named process.

Currently we force the user to be "bind", but I think it makes sense to make this into a changeable setting (just like it is in the Debian package, through /etc/default/named).

This change was prompted by bug #1969756.

[Sergio Durigan Junior (sergiodj)]

If this MP is approved I will work on updating the image's README.

[Bryce Harrington (bryce)]

Yep makes sense. Oversight on my part to not include it as a configurable, sorry.
At least people are evidently looking at the image, that's good. :-)

review: Approve

[Athos Ribeiro (athos-ribeiro)]

review: Approve

[Sergio Durigan Junior (sergiodj)]

Thanks, guys. I'm going to file an MP for the documentation soon.

diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 4c8d14d..d04bfee 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -10,11 +10,15 @@ elif [[ "${1}" == "named" || "${1}" == "$(command -v named)" ]]; then
     set --
 fi
 
+# The user which will start the named process.  If not specified,
+# defaults to 'bind'.
+BIND9_USER="${BIND9_USER:-bind}"
+
 # default behaviour is to launch named
 if [[ -z "${1}" ]]; then
     echo "Starting named..."
-    echo "exec $(which named) -g \"${EXTRA_ARGS}\""
-    exec $(command -v named) -u bind -g ${EXTRA_ARGS}
+    echo "exec $(which named) -u \"${BIND9_USER}\" -g \"${EXTRA_ARGS}\""
+    exec $(command -v named) -u "${BIND9_USER}" -g ${EXTRA_ARGS}
 else
     exec "${@}"
 fi