Add tests for whether mixin output is checked-in

With the proposed workflow mixin output is generated offline and
checked into version control for direct usage.
A test is added to check whether the generated rules and dashboards
match the checked-in version.
Additionally checks for the shellscript generating the mixins and for
the mixin test playbook from above are added.

Signed-off-by: Jan Horstmann <horstmann@osism.tech>

.src/playbooks/mixin-ouput-ensure-git-checkin.yml

@@ -0,0 +1,38 @@
+---
+- name: Run check-shell-syntax
+  connection: local
+  hosts: localhost
+  #hosts: all
+  vars:
+    zuul:
+      project:
+        src_dir: ../..
+  tasks:
+    - name: Build monitoring-mixin container
+      containers.podman.podman_image:
+        name: mixin-builder
+        path: "./{{ zuul.project.src_dir }}/.src"
+        build:
+          file: "./{{ zuul.project.src_dir }}/.src/Containerfile"
+    - name: Install monitoring-mixin dependencies
+      containers.podman.podman_container:
+        command: jb install
+        <<: &mixin_container_options
+          name: mixin-builder
+          image: localhost/mixin-builder
+          detach: false
+          volume:
+            - "./{{ zuul.project.src_dir }}:/srv"
+          rm: true
+    - name: Render monitoring-mixin rules / dashboards
+      containers.podman.podman_container:
+        <<: *mixin_container_options
+    - name: Check difference between git and generated rules / dashboards
+      ansible.builtin.command:
+        argv:
+          - /usr/bin/git
+          - diff
+          - --exit-code
+      register: git_diff
+      changed_when: false
+      failed_when: git_diff.rc != 0

.zuul.yaml

@@ -1,13 +1,32 @@
 ---
+- job:
+    name: mixin-ouput-ensure-git-checkin
+    description: Check for differences between monitoring-mixin output and checked in rules/dashboards
+    run: .src/playbooks/mixin-ouput-ensure-git-checkin.yml
 - project:
     default-branch: main
     merge-mode: squash-merge
     check:
       jobs:
         - yamllint
+        - ansible-lint: &ansible-lint
+            files:
+              - ^\.src/playbooks/.*\.(yaml|yml)$
+        - check-shell-syntax: &check-shell-syntax
+            files:
+              - ^\.src/files/mixins.sh$
+        - mixin-ouput-ensure-git-checkin: &mixin-ouput-ensure-git-checkin
+            files:
+              - ^\.src/.*$
     gate:
       jobs:
         - yamllint
+        - *ansible-lint
+        - *check-shell-syntax
+        - *mixin-ouput-ensure-git-checkin
     periodic-daily:
       jobs:
         - yamllint
+        - *ansible-lint
+        - *check-shell-syntax
+        - *mixin-ouput-ensure-git-checkin