Deploying a Linux-based CI¶
This document contains instructions to build and deploy a new bare-OS CI for Linux. Instructions for deployment assume a freshly installed machine, with Idiap’s latest Debian distribution running. Our builds use Docker images. We also configure docker-in-docker to enable to run docker builds (and other tests) within docker images.
Warning
Idiap has throttling rules that are typically applied to all machines in the lab network. To avoid issues for newly installed CI nodes, ensure you request throttling to be disabled for new CI machines.
Docker and Gitlab-runner setup¶
Base docker installation: https://secure.idiap.ch/intranet/system/software/docker
Ensure to add/configure for auto-loading the overlay kernel module in
/etc/modules. Then update/create /etc/docker/daemon.json to contain
the entry "storage-driver": "overlay2".
To ensure that you can control memory and CPU usage for launched docker
containers, you’ll need to enable “cgroups” on your machine. In essence,
change /etc/default/grub to contain the line
GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1". Then, re-run
update-grub after such change.
To install docker at Idiap, you also need to follow the security guidelines from Cédric at https://secure.idiap.ch/intranet/system/software/docker. If you do not follow such guidelines, the machine will not be acessible from outside via the login gateway, as the default docker installation conflicts with Idiap’s internal setup. You may also find other network connectivity issues.
Also, you want to place /var/lib/docker on a fast disk. Normally, we
have a scratch partition for this. Follow the instructions at
https://linuxconfig.org/how-to-move-docker-s-default-var-lib-docker-to-another-directory-on-ubuntu-debian-linux
for this step:
$ mkdir /scratch/docker
$ chmod g-rw,o-rw /scratch/docker
$ service docker stop
$ rsync -aqxP /var/lib/docker/ /scratch/docker
$ rm -rf /var/lib/docker
$ vim /etc/docker/daemon.json # add data-root -> /scratch/docker
$ service docker start
Reboot the machine to ensure everything works fine.
Hosts section¶
We re-direct calls to www.idiap.ch to our internal server, for speed. Just add this to /etc/hosts:
$ echo "" >> /etc/hosts
$ echo "#We fake www.idiap.ch to keep things internal" >> /etc/hosts
$ echo "What is the internal server IPv4 address?"
$ read ipv4add
$ echo "${ipv4add} www.idiap.ch" >> /etc/hosts
$ echo "What is the internal server IPv6 address?"
$ read ipv6add
$ echo "${ipv6add} www.idiap.ch" >> /etc/hosts
Note
You should obtain the values of the internal IPv4 and IPv6 addresses from inside the Idiap network. We cannot replicate them in this manual for security reasons.
Gitlab runner configuration¶
Once that is setup, install gitlab-runner from https://docs.gitlab.com/runner/install/linux-repository.html, and then register it https://docs.gitlab.com/runner/register/.
We are currently using this kind of configuration (notice you need to replace
the values of <internal.ipv4.address> and <token> on the template below):
concurrent = 20
check_interval = 10
[session_server]
session_timeout = 1800
[[runners]]
name = "<machine-name>"
output_limit = 102400
url = "https://gitlab.idiap.ch/"
token = "<token>"
executor = "shell"
shell = "bash"
builds_dir = "/scratch/builds"
cache_dir = "/scratch/cache"
[[runners]]
name = "bp-srv01"
output_limit = 102400
url = "https://gitlab.idiap.ch/"
token = "<token>"
executor = "docker"
builds_dir = "/scratch/builds"
cache_dir = "/scratch/cache"
[runners.docker]
tls_verify = false
image = "continuumio/conda-concourse-ci"
privileged = false
disable_entrypoint_overwrite = false
oom_kill_disable = false
disable_cache = false
volumes = ["/scratch/cache"]
shm_size = 0
extra_hosts = ["www.idiap.ch:<internal.ipv4.address>"]
[runners.cache]
Insecure = false
Note
You must make both /scratch/builds and /scratch/cache owned by the
user running the gitlab-runner process. Typically, it is
gitlab-runner. These commands, in this case, are in order to complete
the setup:
.. code-block:: sh
$ mkdir /scratch/builds $ chown gitlab-runner:gitlab-runner /scratch/builds $ mkdir /scratch/cache $ chown gitlab-runner:gitlab-runner /scratch/cache
Access to Idiap’s docker registry¶
If you want the Idiap docker registry (docker.idiap.ch) to be accessible from
the shell executors, you must also ensure Idiap registry certificates are
available on the host. You may copy the contents of docker.idiap.ch
directory in this documentation set for that purpose, to the directory
/etc/docker/certs.d. Then, ensure to use something like: docker login -u
gitlab-ci-token -p $CI_JOB_TOKEN docker.idiap.ch on the (global)
before_script phase in jobs requiring access to the registry.
Repository cloning from CI jobs¶
If you’d like to allow the (shell-based) runner to clone repositories other
than the one being built, you need to ensure the following is configured at
~/.ssh/config of the user running the gitlab-runner process
(typically gitlab-runner):
Host gitlab.idiap.ch
ForwardX11 no
ForwardX11Trusted no
ForwardAgent yes
StrictHostKeyChecking no
ControlMaster auto
ControlPath /tmp/%r@%h-%p
ControlPersist 600
Compression yes
Make sure to use an “https” git-clone strategy in your recipes.
Git¶
The version of git (2.11) shipped with Debian Stretch (9.x) is broken. The
git-clean command does not honour the --exclude passed via the
command-line. I advise you install the most recent version from debian
backports by enabling this repository or configuring it with instructions from
https://backports.debian.org. To install the newest git version, after an
apt update, just run the following command as root:
$ apt-get -t stretch-backports install "git"
X11¶
Some utilities such as dot (graphviz) require X11 support. If you intend
to make use of the shell builder and graphviz, you must install basic
X11 support. Just run the following command as root to fix this:
$ apt install libxrender1 libxext6
Crontabs¶
# crontab -l
MAILTO=""
0 12 * * SUN /usr/share/gitlab-runner/clear-docker-cache
Locale¶
Ensure to set the default locale as C.UTF-8 by re-running
dpkg-reconfigure locales. The click (python) package requires it.