xref: /qemu/docs/devel/ci.rst (revision d3a4e41d)
1==
2CI
3==
4
5QEMU has configurations enabled for a number of different CI services.
6The most up to date information about them and their status can be
7found at::
8
9   https://wiki.qemu.org/Testing/CI
10
11Custom CI/CD variables
12======================
13
14QEMU CI pipelines can be tuned by setting some CI environment variables.
15
16Set variable globally in the user's CI namespace
17------------------------------------------------
18
19Variables can be set globally in the user's CI namespace setting.
20
21For further information about how to set these variables, please refer to::
22
23  https://docs.gitlab.com/ee/ci/variables/#add-a-cicd-variable-to-a-project
24
25Set variable manually when pushing a branch or tag to the user's repository
26---------------------------------------------------------------------------
27
28Variables can be set manually when pushing a branch or tag, using
29git-push command line arguments.
30
31Example setting the QEMU_CI_EXAMPLE_VAR variable:
32
33.. code::
34
35   git push -o ci.variable="QEMU_CI_EXAMPLE_VAR=value" myrepo mybranch
36
37For further information about how to set these variables, please refer to::
38
39  https://docs.gitlab.com/ee/user/project/push_options.html#push-options-for-gitlab-cicd
40
41Here is a list of the most used variables:
42
43QEMU_CI_AVOCADO_TESTING
44~~~~~~~~~~~~~~~~~~~~~~~
45By default, tests using the Avocado framework are not run automatically in
46the pipelines (because multiple artifacts have to be downloaded, and if
47these artifacts are not already cached, downloading them make the jobs
48reach the timeout limit). Set this variable to have the tests using the
49Avocado framework run automatically.
50
51Jobs on Custom Runners
52======================
53
54Besides the jobs run under the various CI systems listed before, there
55are a number additional jobs that will run before an actual merge.
56These use the same GitLab CI's service/framework already used for all
57other GitLab based CI jobs, but rely on additional systems, not the
58ones provided by GitLab as "shared runners".
59
60The architecture of GitLab's CI service allows different machines to
61be set up with GitLab's "agent", called gitlab-runner, which will take
62care of running jobs created by events such as a push to a branch.
63Here, the combination of a machine, properly configured with GitLab's
64gitlab-runner, is called a "custom runner".
65
66The GitLab CI jobs definition for the custom runners are located under::
67
68  .gitlab-ci.d/custom-runners.yml
69
70Custom runners entail custom machines.  To see a list of the machines
71currently deployed in the QEMU GitLab CI and their maintainers, please
72refer to the QEMU `wiki <https://wiki.qemu.org/AdminContacts>`__.
73
74Machine Setup Howto
75-------------------
76
77For all Linux based systems, the setup can be mostly automated by the
78execution of two Ansible playbooks.  Create an ``inventory`` file
79under ``scripts/ci/setup``, such as this::
80
81  fully.qualified.domain
82  other.machine.hostname
83
84You may need to set some variables in the inventory file itself.  One
85very common need is to tell Ansible to use a Python 3 interpreter on
86those hosts.  This would look like::
87
88  fully.qualified.domain ansible_python_interpreter=/usr/bin/python3
89  other.machine.hostname ansible_python_interpreter=/usr/bin/python3
90
91Build environment
92~~~~~~~~~~~~~~~~~
93
94The ``scripts/ci/setup/build-environment.yml`` Ansible playbook will
95set up machines with the environment needed to perform builds and run
96QEMU tests.  This playbook consists on the installation of various
97required packages (and a general package update while at it).  It
98currently covers a number of different Linux distributions, but it can
99be expanded to cover other systems.
100
101The minimum required version of Ansible successfully tested in this
102playbook is 2.8.0 (a version check is embedded within the playbook
103itself).  To run the playbook, execute::
104
105  cd scripts/ci/setup
106  ansible-playbook -i inventory build-environment.yml
107
108Please note that most of the tasks in the playbook require superuser
109privileges, such as those from the ``root`` account or those obtained
110by ``sudo``.  If necessary, please refer to ``ansible-playbook``
111options such as ``--become``, ``--become-method``, ``--become-user``
112and ``--ask-become-pass``.
113
114gitlab-runner setup and registration
115~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
116
117The gitlab-runner agent needs to be installed on each machine that
118will run jobs.  The association between a machine and a GitLab project
119happens with a registration token.  To find the registration token for
120your repository/project, navigate on GitLab's web UI to:
121
122 * Settings (the gears-like icon at the bottom of the left hand side
123   vertical toolbar), then
124 * CI/CD, then
125 * Runners, and click on the "Expand" button, then
126 * Under "Set up a specific Runner manually", look for the value under
127   "And this registration token:"
128
129Copy the ``scripts/ci/setup/vars.yml.template`` file to
130``scripts/ci/setup/vars.yml``.  Then, set the
131``gitlab_runner_registration_token`` variable to the value obtained
132earlier.
133
134To run the playbook, execute::
135
136  cd scripts/ci/setup
137  ansible-playbook -i inventory gitlab-runner.yml
138
139Following the registration, it's necessary to configure the runner tags,
140and optionally other configurations on the GitLab UI.  Navigate to:
141
142 * Settings (the gears like icon), then
143 * CI/CD, then
144 * Runners, and click on the "Expand" button, then
145 * "Runners activated for this project", then
146 * Click on the "Edit" icon (next to the "Lock" Icon)
147
148Tags are very important as they are used to route specific jobs to
149specific types of runners, so it's a good idea to double check that
150the automatically created tags are consistent with the OS and
151architecture.  For instance, an Ubuntu 20.04 aarch64 system should
152have tags set as::
153
154  ubuntu_20.04,aarch64
155
156Because the job definition at ``.gitlab-ci.d/custom-runners.yml``
157would contain::
158
159  ubuntu-20.04-aarch64-all:
160   tags:
161   - ubuntu_20.04
162   - aarch64
163
164It's also recommended to:
165
166 * increase the "Maximum job timeout" to something like ``2h``
167 * give it a better Description
168