faq.md

@@ -22,7 +22,67 @@ For verification purposes you can check the list of ildap group members with a c
 
 ## How to use the continuous integration (CI) service?
 
-See [[CI@gitlab.inria.fr|https://gitlab.inria.fr/lnussbau/ci-test]]
+Besides using Inria's Continuous Integration platform [ci.inria.fr](https://ci.inria.fr), you can use gitlab's integrated CI pipelines. This tool is more suited to the execution of simple and lightweight tasks, than for complex deployment pipelines.
+
+You will need to set up a CI runner (small tool in charge of running the CI
+tasks themselves) and then register the runner with your project.
+
+### Enabling CI on a gitlab project
+
+* Go to your project's settings
+* In the *General* tab, search for "Pipelines", and check the permission is not "Disabled"
+* Then a *Pipelines* tab should appear
+* In this *Pipelines* tab, you will find the url and the registration token you will need later, when adding a runner.
+
+### Installing runners
+
+To perform the actual build, you need to install GitLab Runner. Runners can run anywhere : you can use a virtual machine on [ci.inria.fr](https://ci.inria.fr) to host your GitLab runner.
+
+See :
+
+* <https://wiki.inria.fr/ciportal/Web_Portal_Tutorial> to create a slave on Inria's CI platform and access it (you can ignore the jenkins related parts)
+* <https://docs.gitlab.com/runner/install/> for the official documentation to install the runner on the vm(s) you've created. 
+
+### Register a runner in your project
+
+On the virtual machine where you installed the gitlab CI runner, run (as root or sudo!) :
+
+```
+$ sudo gitlab-runner register 
+```
+Use the gitlab URL and the registration token found in the "Pipelines" page when asked.  
+
+In order to answer when asked 
+
+	Please enter the gitlab-ci tags for this runner (comma separated):
+
+it is important to know that "gitlab-ci tags" are NOT git tags. The tags you enter here are useful to specify conditional execution in the configuration file .gitlab-ci.yml.  
+See :
+
+* <https://docs.gitlab.com/ce/ci/yaml/#tags>
+* and <https://docs.gitlab.com/ce/ci/yaml/#only-and-except> 
+
+for more details.
+
+The next question 
+
+	Whether to run untagged builds [true/false]: 
+
+becomes clear when the "gitlab-ci tag" concept is understood.
+
+When asked 
+
+	Please enter the executor:
+you should answer `shell`
+
+At the end of this step, your runner should appear in the *Settings > Pipelines* tab of your project.
+
+
+### Configurating CI tasks
+
+Finally, configure the tasks to run by creating a .gitlab-ci.yml file at the root of your project.  
+Follow the official documentation at <https://docs.gitlab.com/ce/ci/yaml/> to create this file. 
+
 
 ## Git-LFS is not activated