Use dumb-init to manage the pid 1 process

Normally, when you launch a Docker container, the process you're
executing becomes PID 1, giving it the quirks and responsibilities that
come with being the init system for the container.

There are two common issues this presents:

* In most cases, signals won't be handled properly.
* Orphaned zombie processes aren't properly reaped.

the dumb-init acting like a simple init system. It launches a single
process and then proxies all received signals to a session rooted at
that child process.

Closes-Bug: #1614509
Change-Id: I9d3d04648e151ddc7c6732b92ffd3b6c9fe467ec

docker/base/Dockerfile.j2

@@ -262,6 +262,8 @@ RUN touch /usr/local/bin/kolla_extend_start \
     && chmod 755 /usr/local/bin/kolla_start /usr/local/bin/kolla_extend_start /usr/local/bin/kolla_set_configs \
     && chmod 440 /etc/sudoers \
     && groupadd kolla \
-    && rm -f /tmp/kolla_bashrc
+    && rm -f /tmp/kolla_bashrc \
+    && curl -sSL https://github.com/Yelp/dumb-init/releases/download/v1.1.3/dumb-init_1.1.3_amd64 -o /usr/local/bin/dumb-init \
+    && chmod +x /usr/local/bin/dumb-init
 
 CMD ["kolla_start"]

docker/base/start.sh

-#!/bin/bash
+#!/usr/local/bin/dumb-init /bin/bash
 set -o errexit
 
 # Wait for the log socket

docker/kolla-toolbox/Dockerfile.j2

@@ -66,7 +66,7 @@ COPY ansible.cfg /home/ansible/.ansible.cfg
 COPY ansible_sudoers /etc/sudoers.d/ansible_sudoers
 RUN chmod 440 /etc/sudoers.d/ansible_sudoers
 
-CMD ["/bin/sleep", "infinity"]
+CMD ["/usr/local/bin/dumb-init", "/bin/sleep", "infinity"]
 
 {% block kolla_toolbox_footer %}{% endblock %}
 {% block footer %}{% endblock %}

releasenotes/notes/add-dumb-init-manage-root-process-e25a529b322d4fac.yaml

+---
+features:
+  - use dumb-init to manage the pid 1 process