Some improvement and fixes

[axeltorchy]

This pull request is made of 4 commits, each addressing a specific additional feature or bug fix.

1. Added possibility to skip tasks that require privilege escalation (become) [8c322e1]
We might want to run the Ansible playbook without executing any of the tasks that require privilege escalation. For example, if we don't need to deploy any component and only want to push the new tests pipeline into the scheduler and TestAPI.

This change adds a new boolean variable become_tasks which defaults to true. It is used as a condition for all tasks that required privilege escalation. For tasks where privilege escalation depended on a condition (e.g. become: "{{ ansible_connection is defined }}"), the skipping condition in when includes the "or" and negation of this condition so that the task is not skipped when privilege escalation was not needed. In that example, the condition will be become_tasks or ansible_connection is not defined.

2. Added possibility to change Jenkins agent's name (w/o K8s) [d81816f]
This is necessary if we want to use the Ansible role to deploy multiple Jenkins agents on the same machine. It was not possible because the container name was hardcoded and always the same: "jenkins-agent".
A new variable is added: jenkins_agent_auto_container_name, which defaults to jenkins-agent. It is used in the "Starting Jenkins agent" task, when kubernetes_deploy is false.

3. Added disjoint URLs for TestAPI deploy and test execution vars [641edf3]
The same variable testapi_url was used in two different contexts:

• when registering the pod/project/testcases in TestAPI (job deployment phase)
• by the test container following test execution to push test results to TestAPI (passed as environment variables)

A new variable is added: testapi_deploy_url, whch defaults to the value of testapi_url.

It is now possible to use a different endpoint for these two actions, which is useful because if the runner is not located on the machine where the playbook is executed then it may not be able to reach TestAPI via the same URL.

4. Fixed wrong TestAPI pod name registration [90283c0]
There was a discrepancy between the pod name registration and the pod_name used by the container when trying to push results to TestAPI (see https://github.com/opnfv/functest-xtesting/blob/861f79d46397d8bbc5b55b95bc4ca2ac0fb1f247/xtesting/core/testcase.py#L222)

The registration tasks used the value of the project variable from the Ansible playbook, whereas the test container used the NODE_NAME environment variable (defined in run.yaml.j2, either equal to the slave name or to node_name if use_slave is false).

The change proposes to register the pods based on the values of the slave variables in the Docker tags if defined (or node_name if not defined). It adds a loop in the task and makes it possible to register multiple pods.

[axeltorchy]

Hello @collivier, have you had the chance to consider the proposed changes? What is your opinion about them?