Test ansible scripts with default linter

We use the github action runner as the machine to test against. The
connection is local instead of ssh to make this simpler.

We also fix the bug that when the service does not exist we cannot start
the ansible books anymore.

The used credentials are default and insecure.

Author: vmcj

.github/workflows/ansible-deployments.yml

@@ -0,0 +1,30 @@
+name: Test contest deployment (ansible scripts)
+
+on: [push,pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+      - name: Install ansible lint tools
+        run: sudo apt update; sudo apt install ansible-lint
+      - name: Lint the different scripts 
+        run: cd icpc-wf/ansible; ansible-lint .
+  test_judgedaemon_role:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+      - name: Install ansible lint tools
+        run: sudo apt update; sudo apt install ansible
+      - name: Setup the hosts file
+        working-directory: ./icpc-wf/ansible
+        run: sed -i 's/\[judgehost\]/[removed]/g' hosts; printf '\n[judgehost]\ngithub-action\tansible_host=localhost ansible_connection=local' >> hosts
+      - name: Generate insecure credentials
+        working-directory: ./icpc-wf/ansible
+        run: mv group_vars/all/secret.yml{.example,}
+      - name: Run the default deployment method
+        working-directory: ./icpc-wf/ansible
+        run: make judgehost

icpc-wf/ansible/judgehost.yml

@@ -41,11 +41,14 @@
       tags: prometheus_target_all
       when: GRAFANA_MONITORING
   pre_tasks:
+    - name: Get current services
+      service_facts:
     - name: Disable all cores
       service:
         name="domjudge-judgedaemon@{{item}}"
         state=stopped
       with_sequence: start=0 end={{ ansible_processor_vcpus }} format=domjudge-judgedaemon@%1x
+      when: '"[email protected]" in services'
   tasks:
     - name: add autostart shortcuts
       template: