Refactor and improve distributed sqlite integration test coverage

This removes the job "ansible-role-ara-api-fedora-distributed-sqlite" and replaces
it by "ara-api-distributed-sqlite".

The job tests the support for the distributed sqlite database backend
Fedora and Ubuntu simultaneously, allowing for the addition of CentOS8
in the future.

Change-Id: I5851b4364fd567799e92feda5c41b34e5a22dc49

.zuul.d/jobs.yaml

@@ -49,3 +49,12 @@
       ARA API clients as well as the API itself.
     run: tests/with_mysql.yaml
     post-run: tests/zuul_post_with_mysql.yaml
+
+- job:
+    name: ara-api-distributed-sqlite
+    parent: ara-api-database-backends
+    nodeset: ara-multinode
+    description: |
+      Deploys the ARA API server on Ubuntu 18.04 as well as Fedora 30 and
+      tests it using the distributed sqlite database backend.
+    run: tests/with_distributed_sqlite.yaml

.zuul.d/nodesets.yaml

@@ -17,3 +17,18 @@
         nodes:
           - ubuntu-bionic
           - fedora-30
+
+# Nodeset used to test instances of ARA API deployed on different operating
+# systems simultaneously.
+- nodeset:
+    name: ara-multinode
+    nodes:
+      - name: ubuntu-bionic
+        label: ubuntu-bionic
+      - name: fedora-30
+        label: fedora-30
+    groups:
+      - name: ara-api-server
+        nodes:
+          - ubuntu-bionic
+          - fedora-30

.zuul.d/project.yaml

@@ -5,13 +5,13 @@
       - docs-on-readthedocs
     check:
       jobs:
+        - ara-api-distributed-sqlite
         - ara-api-mysql
         - ara-api-postgresql
         - ansible-role-ara-api-fedora-devel
         - ansible-role-ara-api-fedora-2.9
         - ansible-role-ara-api-ubuntu-2.8
         - ansible-role-ara-api-ubuntu-2.7
-        - ansible-role-ara-api-fedora-distributed-sqlite
         - ansible-role-ara-api-fedora-packages:
             voting: false
         - ansible-role-ara-web-ubuntu
@@ -21,13 +21,13 @@
         - ara-tox-py3
     gate:
       jobs:
+        - ara-api-distributed-sqlite
         - ara-api-mysql
         - ara-api-postgresql
         - ansible-role-ara-api-fedora-devel
         - ansible-role-ara-api-fedora-2.9
         - ansible-role-ara-api-ubuntu-2.8
         - ansible-role-ara-api-ubuntu-2.7
-        - ansible-role-ara-api-fedora-distributed-sqlite
         - ansible-role-ara-web-ubuntu
         - ansible-role-ara-web-fedora
         - ara-basic-ansible-integration

.zuul.d/role-jobs.yaml

@@ -74,14 +74,6 @@
       - name: github.com/ansible/ansible
         override-checkout: stable-2.7
 
-# Database server jobs
-- job:
-    name: ansible-role-ara-api-fedora-distributed-sqlite
-    parent: ansible-role-ara-api-fedora
-    roles:
-      - zuul: zuul/zuul-jobs
-    run: tests/with_distributed_sqlite.yaml
-
 # Distribution package tests
 
 - job:

tests/vars/distributed_sqlite_tests.yaml

@@ -0,0 +1,14 @@
+ara_tests_cleanup: true
+ara_api_root_dir: "{{ ansible_user_dir }}/.ara-tests"
+ara_api_distributed_sqlite_root: "{{ ansible_user_dir }}/.ara-tests"
+ara_api_distributed_sqlite_prefix: ara-test-report
+ara_api_wsgi_server: gunicorn
+ara_api_secret_key: testing
+ara_api_debug: true
+ara_api_log_level: DEBUG
+ara_api_server: "http://127.0.0.1:8000"
+ara_api_client: http
+_test_directories:
+  - "tests/some/path/ara-test-report"
+  - "tests/dev/ara-test-report"
+  - "tests/prod/ara-test-report"

tests/with_distributed_sqlite.yaml

@@ -18,21 +18,8 @@
 - name: Test the ARA API with the distributed sqlite backend
   hosts: all
   gather_facts: yes
-  vars:
-    ara_tests_cleanup: true
-    ara_api_root_dir: "{{ ansible_user_dir }}/.ara-tests"
-    ara_api_distributed_sqlite_root: "{{ ansible_user_dir }}/.ara-tests"
-    ara_api_distributed_sqlite_prefix: ara-test-report
-    ara_api_wsgi_server: gunicorn
-    ara_api_secret_key: testing
-    ara_api_debug: true
-    ara_api_log_level: DEBUG
-    ara_api_server: "http://127.0.0.1:8000"
-    ara_api_client: http
-    _test_directories:
-      - "tests/some/path/ara-test-report"
-      - "tests/dev/ara-test-report"
-      - "tests/prod/ara-test-report"
+  vars_files:
+    - vars/distributed_sqlite_tests.yaml
   tasks:
     # Generate ourselves a fresh database to run tests with
     - name: Set up the API with the default sqlite backend