doc/researchAnsible: documented the work to setup and start a Jenkins

The topic Jcasc was already handled. With this commit we are able to
setup a Jenkins by using docker-compose.

Signed-off-by: Marc Mattmüller <marc.mattmueller@netmodule.com>

doc/src/nextlevel-ci/researchAnsible.rst

@@ -911,6 +911,127 @@ After Lauching the job, I checked the docker images directly on the server:
 Oh yes, this works too - **Party!**
 
 
+Job to Start a Jenkins Instance
+*******************************
+See the following matching table about what we have done so far and what is needed:
+
+=============================================  ===========================================  =======
+ What we already have                           What to we need                              Ready
+=============================================  ===========================================  =======
+ Configured a VM / host                         a host                                         x
+ SSH key pair for access to services            ssh key for git access                         x
+ Clone a git repository                         the repository cloned                          x
+ Build the Jenkins docker image                 the jenkins controller docker image            x
+ Jcasc from the CoreOS proof of concept         the docker compose files
+ data for known_hosts and authorization         authorization and known_host files
+ nexus user and password                        passwords encrypted for ssh, users, nexus
+=============================================  ===========================================  =======
+
+From this table we see that we are nearly ready. So these are the tasks to be performed until we have all necessary
+things to deploy the new Jenkins with a playbook:
+
+#.  Prepare the nwl-ci repository by adding the Jenkins Controller parts according this tree:
+
+    .. code-block:: bash
+
+        .
+        ├── docker-compose.yaml
+        └── docker
+            └── nwl-cicd.yaml
+
+#.  Create a playbook performing tasks within the cloned nwl-ci repository. Tasks like:
+
+     #)  adding new directories on the target host:
+
+          .. code-block:: bash
+
+              .
+              ├── jenkins_home
+              ├── secrets
+              │   ├── pw
+              │   ├── .cacerts
+              │   └── .ssh
+              └── yocto-downloads
+
+     #)  creating the following content on the target host:
+
+          .. code-block:: bash
+
+              .
+              ├── docker-compose.yaml
+              ├── docker
+              │   ├── nwl-cicd.yaml
+              │   ├── Dockerfile
+              │   └── plugins.txt
+              ├── jenkins_home
+              ├── jobs
+              │   ├── Jenkinsfile_Build
+              │   ├── Jenkinsfile_Common
+              │   └── nwlTargets
+              ├── secrets
+              │   ├── pw
+              │   │   ├── gitSsh --> testvm_ed25519
+              │   │   ├── jenkinsUserAdmin
+              │   │   ├── jenkinsUserDeveloper
+              │   │   └── nexusUser
+              │   ├── .cacerts
+              │   └── .ssh
+              │       ├── authorized_keys
+              │       ├── known_hosts
+              │       ├── testvm_ed25519
+              │       └── testvm_ed25519.pub
+              └── yocto-downloads
+
+          .. note::
+              As a reminder you can create the pw using the AWX vault as follows:
+
+              ``echo -n 'vmSSHpassphrase!' | ansible-vault encrypt_string --ask-vault-pass``
+
+#.  Create a playbook bringing the Jenkins instance up
+#.  **NOTE:** Before doing the next step you have to commit and push your changes and then launch the job
+    *Clone CI Repo* to update the repository on the server
+#.  Create a new Job Templates in AWX for the newly created playbooks:
+
+     *  Select the menu *Resources* >> *Templates* and click *Add*:
+
+         -  Enter a name, e.g. *Setup CI Environment*
+         -  Enter a description, e.g. *Setting up a Jenkins CI environment using docker-compose*
+         -  Select  ``Run`` as Job Type
+         -  Select ``Testenv`` as Organization
+         -  Select  ``Production`` as Inventory
+         -  Select  ``NWL CI`` as Project
+         -  Select  ``playbooks/getting_started/setup-nwl-jenkins.yaml`` as Playbook
+         -  Select the following:
+
+             +  Switch the drop-down of *Selected Category* to Machine and then check ``Machine Access``
+             +  Switch the drop-down of *Selected Category* to Vault and then check ``Vault Password | nwl-vault``
+
+         -  Press Save
+
+     *  Select the menu *Resources* >> *Templates* and click *Add*:
+
+         -  Enter a name, e.g. *Start-Stop CI Instance*
+         -  Enter a description, e.g. *Start or Stop the Jenkins CI instance*
+         -  Select  ``Run`` as Job Type
+         -  Select ``Testenv`` as Organization
+         -  Select  ``Production`` as Inventory
+         -  Select  ``NWL CI`` as Project
+         -  Select  ``playbooks/getting_started/start-stop-nwl-jenkins.yml`` as Playbook
+         -  Select the following:
+
+             +  Switch the drop-down of *Selected Category* to Machine and then check ``Machine Access``
+
+         -  Enter ``power_status: "start"`` in Variables and check *Prompt on launch*
+
+             +  Change the variable at launch time to ``power_status: "stop"`` to bring the instance down
+
+         -  Press Save
+
+#.  Launch the Jjob *Setup CI Environment*
+#.  Bring the instance up by launching the job *Start-Stop CI Instance* (keep the variable as it is)
+
+
+
 
 Combining Playbooks
 ###################