Run some tests just if plugin is installed.

When having different branches, with different plugins, some branches test different plugins that other ones.

I wanted the same CI to select dynamically different test case scenarios.
To keep compatibility some conditional has to be added.

.gitlab/test.yml

+workflow:
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "parent_pipeline"
+
+.test-core: &test-core
+  stage: test
+  tags:
+    - debian12_ovh
+  variables:
+    TEST_TAG: test
+    TEST_HOST: localhost
+    TEST_PORT: 8000
+
+up-test-env-job:
+  <<: *test-core
+  before_script:
+    # check that no other unrelated Netbox is up on destination port.
+    - if [[ $(curl -f -s http://${TEST_HOST}:${TEST_PORT}/metrics |wc -l) != 0 ]];
+        then echo "WARNING!! An unrelated Netbox instace has not been shut down properly. Try again, or execute down-test-env-job manually."; exit 1;
+      fi
+    # check that runner can do `docker-in-docker`.
+    - docker info
+    # Build image to test
+    - docker build --no-cache -t code.europa.eu:4567/digit-c4/netbox-plugins:${TEST_TAG} .
+  script:
+    # Netbox up `http://localhost:8000`
+    - env TAG=${TEST_TAG} PORT=${TEST_PORT} docker compose -f docker-compose.yml -f docker-compose.test.yml up -d
+    # wait for netbox to be up and running
+    - for ((i=1; i<20; i++)); do
+        if [[ $(curl -f -s http://${TEST_HOST}:${TEST_PORT}/metrics |wc -l) < 250 ]];
+          then echo "not yet up, sleep for 20 seconds.."; sleep 20;
+          else echo "Netbox up, we are able to reach metrics page. http://${TEST_HOST}:${TEST_PORT}/metrics."; break;
+        fi;
+        if [[ $i == 19 ]];
+          then echo "Netbox seems not able to start on ${TEST_HOST}:${TEST_PORT}."; exit 1;
+        fi;
+      done
+
+run-test-job:
+  <<: *test-core
+  before_script:
+    - python3 -m venv "$CI_PROJECT_DIR/plugins/venv"
+    - source "$CI_PROJECT_DIR/plugins/venv/bin/activate"
+    - pip install -r "$CI_PROJECT_DIR/tests/requirements.e2e.txt"
+    # Remove some tests if plugins are not installed, to keep CI compatibility with different testing branches.
+    - for str in {cert,mac,rps}; do
+        if [[ $(cat requirements.txt | grep -e ${str} | wc -l)  == 0 ]]; then
+          rm -r $CI_PROJECT_DIR/tests/e2e/netbox/netbox_${str}*_plugin;
+          echo "Removed ${str}'s python tests.";
+        fi;
+      done
+  script:
+    - env HOST="${TEST_HOST}" PORT="${TEST_PORT}" API_KEY="$API_KEY" pytest -s --junit-xml=tests-report-netbox-dist-plugin.xml "$CI_PROJECT_DIR/tests/e2e/"
+  after_script:
+    - deactivate
+    - rm -rf "$CI_PROJECT_DIR/plugins/venv"
+  artifacts:
+    when: always
+    reports:
+      junit: tests-report-netbox-*-plugin.xml
+  needs:
+    - up-test-env-job
+
+run-robot-test-job:
+  <<: *test-core
+  before_script:
+    - python3 -m venv "$CI_PROJECT_DIR/plugins/venv"
+    - source "$CI_PROJECT_DIR/plugins/venv/bin/activate"
+    - docker build -t robotframework:latest ./tests/docker/
+    # Remove some tests if plugins are not installed, to keep CI compatibility with different testing branches.
+    - for str in {mac,}; do
+        if [[ $(cat requirements.txt | grep -e ${str} | wc -l)  == 0 ]]; then
+          rm -r $CI_PROJECT_DIR/tests/robot/netbox_${str}*_plugin;
+          echo "Removed ${str}'s robot tests.";
+        fi;
+      done
+  script:
+    - docker run --rm -v $CI_PROJECT_DIR:/project --network "host" robotframework:latest bash -c
+      "robot -v HOST:"${TEST_HOST}" -v PORT:"${TEST_PORT}" -v API_TOKEN:"$API_KEY" --outputdir /project/reports /project/tests/robot/"
+  after_script:
+    - sudo chmod -R 777 reports
+    - docker image rm robotframework:latest --force
+    - deactivate
+    - rm -rf "$CI_PROJECT_DIR/plugins/venv"
+  artifacts:
+    when: always
+    paths:
+      - reports/*
+  needs:
+    - up-test-env-job
+    - run-test-job
+
+down-test-env-job:
+  <<: *test-core
+  script:
+    - echo "Test Env Down"
+    - env TAG=${TEST_TAG} PORT=${TEST_PORT} docker compose -f docker-compose.yml -f docker-compose.test.yml down -v
+  after_script:
+    - docker image rm code.europa.eu:4567/digit-c4/netbox-plugins:${TEST_TAG} --force
+    - docker image ls
+  needs:
+    - up-test-env-job
+    - run-test-job
+    - run-robot-test-job
+  when: always