doc: update containerized deployment

This adds more documentation to the configuration and usage of
containerizerd deployment.

Closes: #6198

Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>
(cherry picked from commit d42d584085)

docs/source/installation/containerized.rst

@@ -2,3 +2,60 @@ Containerized deployment
 ========================
 
 Ceph-ansible supports docker and podman only in order to deploy Ceph in a containerized context.
+
+Configuration and Usage
+-----------------------
+
+To deploy ceph in containers, you will need to set the ``containerized_deployment`` variable to ``true`` and use the site-container.yml.sample playbook.
+
+.. code-block:: yaml
+
+   containerized_deployment: true
+
+The ``ceph_origin``, ``ceph_repository`` and ``ceph_stable_release`` variables aren't needed anymore in containerized deployment and are ignored.
+
+.. code-block:: console
+
+   $ ansible-playbook site-container.yml.sample
+
+.. note::
+
+   The infrastructure playbooks are working for both non containerized and containerized deployment.
+
+Custom container image
+----------------------
+
+You can configure your own container register, image and tag by using the ``ceph_docker_registry``, ``ceph_docker_image`` and ``ceph_docker_image_tag`` variables.
+
+.. code-block:: yaml
+
+   ceph_docker_registry: quay.ceph.io
+   ceph_docker_image: ceph-ci/daemon
+   ceph_docker_image_tag: latest
+
+.. note::
+
+   ``ceph_docker_image`` should have both image namespace and image name concatenated and separated by a slash character.
+
+Container registry authentication
+---------------------------------
+
+When using a container registry with authentication then you need to set the ``ceph_docker_registry_auth`` variable to ``true`` and provide the credentials via the
+``ceph_docker_registry_username`` and ``ceph_docker_registry_password`` variables
+
+.. code-block:: yaml
+
+   ceph_docker_registry_auth: true
+   ceph_docker_registry_username: foo
+   ceph_docker_registry_password: bar
+
+Container registry behind a proxy
+---------------------------------
+
+When using a container registry reachable via a http(s) proxy then you need to set the ``ceph_docker_http_proxy`` and/or ``ceph_docker_https_proxy`` variables. If you need
+to exclude some host for the proxy configuration to can use the ``ceph_docker_no_proxy`` variable.
+
+.. code-block:: yaml
+
+   ceph_docker_http_proxy: http://192.168.42.100:8080
+   ceph_docker_https_proxy: https://192.168.42.100:8080