Add config option use_dumb_init to add it to container images

Usage of dumb-init can also be disabled from cli with
`--nouse-dumb-init` when building images.

Also moves ENTRYPOINT outside of dumb_init_installation
block.

Change-Id: Id32d54fc9913b83cf121ede5a5e265e0772062ae
Related-Bug: #1821970

docker/base/Dockerfile.j2

@@ -404,8 +404,9 @@ COPY start.sh /usr/local/bin/kolla_start
 COPY sudoers /etc/sudoers
 COPY curlrc /root/.curlrc
 
-{% block dumb_init_installation %}
+{% if use_dumb_init %}
 
+{% block dumb_init_installation %}
 {% if base_arch == 'x86_64' %}
 
 RUN curl -sSL https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_{{debian_arch}} -o /usr/local/bin/dumb-init \
@@ -425,10 +426,11 @@ RUN curl -sSL http://deb.debian.org/debian/pool/main/d/dumb-init/{{dumb_init_pac
     && rm data.tar.xz {{dumb_init_package_name}}
 
 {% endif %}
+{% endblock %}
 
 ENTRYPOINT ["dumb-init", "--single-child", "--"]
 
-{% endblock %}
+{% endif %}
 
 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 \

docker/mariadb/Dockerfile.j2

@@ -52,15 +52,18 @@ RUN chmod 755 /usr/local/bin/kolla_extend_start \
 RUN mkdir -p /var/run/mysqld && chown mysql /var/run/mysqld && chmod 755 /var/run/mysqld
 {% endif %}
 
+{% if use_dumb_init %}
 {% block mariadb_entrypoint %}
 # NOTE(mgoddard): Override the dumb-init arguments to avoid passing
 # --single-child. This does not play well with mysqld_safe, which ignores
 # SIGTERM, meaning Docker needs to forcibly kill the container to stop it.
 # Without --single-child, the TERM signal is sent to all subprocesses,
 # including mysqld.
-ENTRYPOINT ["dumb-init"]
+
+ENTRYPOINT ["dumb-init", "--"]
 CMD ["kolla_start"]
 {% endblock %}
+{% endif %}
 
 {% block mariadb_footer %}{% endblock %}
 {% block footer %}{% endblock %}

kolla/common/config.py

@@ -184,6 +184,8 @@ _CLI_OPTS = [
     cfg.StrOpt('base-arch', default=hostarch,
                choices=BASE_ARCH,
                help='The base architecture. Default is same as host.'),
+    cfg.BoolOpt('use-dumb-init', default=True,
+                help='Use dumb-init as init system in containers'),
     cfg.BoolOpt('debug', short='d', default=False,
                 help='Turn on debugging log level'),
     cfg.BoolOpt('skip-parents', default=False,

kolla/image/build.py

@@ -681,6 +681,7 @@ class KollaWorker(object):
         else:
             self.namespace = conf.namespace
         self.base = conf.base
+        self.use_dumb_init = conf.use_dumb_init
         self.base_tag = conf.base_tag
         self.install_type = conf.install_type
         self.tag = conf.tag
@@ -926,6 +927,7 @@ class KollaWorker(object):
                       'base_image': self.conf.base_image,
                       'base_distro_tag': self.base_tag,
                       'base_arch': self.base_arch,
+                      'use_dumb_init': self.use_dumb_init,
                       'base_package_type': self.base_package_type,
                       'debian_arch': self.debian_arch,
                       'supported_distro_release': supported_distro_release,

releasenotes/notes/add-use-dumb-init-config-option-26b47f6d97d7585c.yaml

@@ -0,0 +1,15 @@
+---
+features:
+  - |
+    Adds configration option ``use_dumb_init``, with default value of ``True``.
+    This can be use to avoid the of ``dumb-init`` as the container entrypoint,
+    using ``kolla_start`` directly instead. This option can also be disabled
+    via the ``kolla-build --nouse-dumb-init`` CLI argument.
+upgrade:
+  - |
+    Moves the ``ENTRYPOINT`` statement outside of the
+    ``dumb_init_installation`` Jinja block in the base image. Overriding this
+    block to install ``dumb-init`` by another method no longer requires
+    repeating the ``ENTRYPOINT`` statement. Users wishing to avoid the use of
+    ``dumb-init`` altogether can now use the ``use_dumb_init`` configuration
+    option.