Add option to skip kolla docker registry login

This change adds a variable that can be used to disable kolla docker
registry login attempts, even when the registry username and password
are set.

This is required for deployments using a non-standard containerised
registry deployed on the seed during the deploy-container step,
since it takes place after the registry login attempt.

Change-Id: Ie17ef9ce1147cbaec2e42db932c7d59293b49b1b
(cherry picked from commit 57d7764)

ansible/roles/deploy-containers/defaults/main.yml

@@ -11,3 +11,5 @@ deploy_containers_defaults:
   restart_policy: "unless-stopped"
 
 deploy_containers_docker_api_timeout: 120
+
+deploy_containers_registry_attempt_login: "{{ kolla_docker_registry_username is truthy and kolla_docker_registry_password is truthy }}"

ansible/roles/deploy-containers/tasks/main.yml

@@ -6,8 +6,7 @@
     password: "{{ kolla_docker_registry_password }}"
     reauthorize: yes
   when:
-    - kolla_docker_registry_username is truthy
-    - kolla_docker_registry_password is truthy
+    - deploy_containers_registry_attempt_login | bool
 
 - name: Deploy containers (loop)
   include_tasks: deploy.yml

doc/source/configuration/reference/seed-custom-containers.rst

@@ -60,3 +60,26 @@ List of Kayobe applied defaults to required docker_container variables:
 .. literalinclude:: ../../../../ansible/roles/deploy-containers/defaults/main.yml
     :language: yaml
 
+
+Docker registry
+===============
+
+Seed containers can be pulled from a docker registry deployed on the seed,
+since the docker registry deployment step precedes the custom container
+deployment step.
+
+It is also possible to deploy a custom containerised docker registry as a
+custom seed container. In this case, basic authentication login attempts can be
+disabled by setting
+
+.. code-block:: yaml
+   :caption: ``kolla.yml``
+
+   deploy_containers_registry_attempt_login: false
+
+Without this setting, the login will fail because the registry has not yet been
+deployed.
+
+More information on deploying a docker registry can be found :ref:`here
+<configuration-docker-registry>`.
+

releasenotes/notes/skip-kolla-docker-registry-login-f5b0ba858a35ea39.yaml

@@ -0,0 +1,9 @@
+---
+features:
+  - |
+    Attempts to log in to the kolla docker registry can be skipped by setting
+    ``deploy_containers_registry_attempt_login`` to false.
+
+    This is required for deployments using a non-standard registry
+    deployed on the seed during the deploy-container step, since it takes
+    place after the registry login attempt.