Merge ~barryprice/charm-k8s-bind/+git/charm-k8s-bind:wrapper into charm-k8s-bind:master

[Barry Price]

Convert from using both ENTRYPOINT and CMD to a single wrapper script that sets up our config and then starts the bind service

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Tom Haddon (mthaddon)]

LGTM

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 04821b38c11acb7a7f452ae3eeaa1ddb3e2406c9

diff --git a/Makefile b/Makefile
index 35b100d..564aeb9 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ image-deps:
 
 image-lint: image-deps
 	@echo "Running shellcheck."
-	@shellcheck image-scripts/docker-entrypoint.sh
+	@shellcheck image-scripts/docker-wrapper.sh
 	@shellcheck image-scripts/dns-check.sh
 
 image-build: image-lint
diff --git a/dockerfile b/dockerfile
index 968d4fd..94856fb 100644
--- a/dockerfile
+++ b/dockerfile
@@ -19,15 +19,14 @@ RUN apt-get update && apt-get -y dist-upgrade \
     && apt-get --purge autoremove -y \
     && apt-get install -y bind9 dnsutils git ${EXTRA_PKGS_TO_INSTALL}
 
-# entrypoint script will configure Bind based on env variables
+# wrapper script will configure Bind based on env variables and run it
 # dns-check script will provide a readinessProbe
-COPY ./image-scripts/docker-entrypoint.sh /usr/local/bin/
+COPY ./image-scripts/docker-wrapper.sh /usr/local/bin/
 COPY ./image-scripts/dns-check.sh /usr/local/bin/
-RUN chmod 0755 /usr/local/bin/docker-entrypoint.sh
+RUN chmod 0755 /usr/local/bin/docker-wrapper.sh
 RUN chmod 0755 /usr/local/bin/dns-check.sh
 
 EXPOSE 53/udp
 EXPOSE 53/tcp
 
-ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
-CMD /usr/sbin/named -g -u bind -c /etc/bind/named.conf
+CMD ["/usr/local/bin/docker-wrapper.sh"]
diff --git a/image-scripts/docker-entrypoint.sh b/image-scripts/docker-wrapper.sh
similarity index 97%
rename from image-scripts/docker-entrypoint.sh
rename to image-scripts/docker-wrapper.sh
index 2ed0857..4f807e1 100644
--- a/image-scripts/docker-entrypoint.sh
+++ b/image-scripts/docker-wrapper.sh
@@ -21,3 +21,5 @@ if [ -d "${BIND_CONFDIR}" ]; then
 else
 	echo "Something went wrong, ${BIND_CONFDIR} does not exist, not starting";
 fi
+
+/usr/sbin/named -g -u bind -c /etc/bind/named.conf