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
(cherry picked from commit 6710bbeb7c)

docker/base/Dockerfile.j2

@@ -209,6 +209,8 @@ RUN touch /usr/local/bin/kolla_extend_start \
     && chmod 440 /etc/sudoers \
     && groupadd kolla
 
-RUN rm -f /tmp/kolla_bashrc
+RUN 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

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/local/bin/dumb-init /bin/bash
 set -o errexit
 
 # Wait for the log socket

docker/kolla-toolbox/Dockerfile.j2

@@ -49,7 +49,7 @@ RUN useradd -m --user-group ansible --groups kolla \
 COPY find_disks.py kolla_keystone_service.py kolla_keystone_user.py kolla_sanity.py kolla_zookeeper.py /usr/share/ansible/
 COPY ansible.cfg /home/ansible/.ansible.cfg
 
-CMD ["/bin/sleep", "infinity"]
+CMD ["/usr/local/bin/dumb-init", "/bin/sleep", "infinity"]
 
 {{ include_footer }}
 

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

@@ -0,0 +1,3 @@
+---
+features:
+  - use dumb-init to manage the pid 1 process