Deploy GitLab on OpenShift

GitLab is a great web git repository application for everyone that wants to run his own Git repository at home or office. Unfortunately, the home made GitLab installation requires some skills that I don’t have to learn. The good thing is that some Docker images exists on Docker Hub, even the one from GitLab team. In this blog post, we will use
the sameersbn docker-gitlab image which demonstrated to working very well, supports volumes and also bring separate containers for postgresql and redis.

Installing postgres

For convenience reasons (and also for support if your are using OpenShift Enterprise), we are using the PostgreSQL image provided by OpenShift team to start ou postgresql instance. The image supports persistent volumes and will create the Persistent Volume Claim for you.

Simply use the oc new-app command to get your PostgreSQL instance up and running. Note that there an issue with this image that runs with a predefined user, you will have to allow it to run as AnyUid by using the corresponding Security Context Constraint.

oc new-app --template=postgresql-persistent \
           -p POSTGRESQL_USER=admin,POSTGRESQL_PASSWORD=redhat,POSTGRESQL_DATABASE=gitlab
--> Deploying template postgresql-persistent in project openshift for "postgresql-persistent"
     With parameters:
      DATABASE_SERVICE_NAME=postgresql
      POSTGRESQL_USER=admin
      POSTGRESQL_PASSWORD=admin
      POSTGRESQL_DATABASE=gitlab
      VOLUME_CAPACITY=512Mi
--> Creating resources ...
    Service "postgresql" created
    Persistentvolumeclaims "postgresql" created
    DeploymentConfig "postgresql" created

Configuring Security Context

Some of the containers that we will use need to run as root (GitLab) or any other user (Postgres has hardcoded user 26 but this will be fixed soon).
Hence, it is required to used the project’s service account (here we created a project called gitlab) to the SCC named anyuid.

oc edit scc anyuid
[...]
supplementalGroups:
  type: RunAsAny
users:
- system:serviceaccount:gitlab:default

This configuration will work for postgres and gitlab image.

Installing Redis

Use the oc new-app command here again and directly pass it the Docker image name and you will get a redis instance up and running in seconds.

oc new-app  sameersbn/redis
[...]
    Service "redis" created
--> Success
    Run 'oc status' to view your app.
<pre>
The new-app command will create Services, EndPoints and associated pods.
It is still required to add a persistent volume to the Deployment Configuration using the following command:
<pre>
oc volume dc/redis --add --overwrite -t persistentVolumeClaim \
                        --claim-name=redis-data --name=redis-volume-1 \
                        --mount-path=/var/lib/redis

Installing GitLab itself

The sameersbn image allows several parameters to be injected in order to configure the GitLab instance to be created.
For some reasons Services name resolutions are not working with the provided startup script, although going into the container and pinging the services works.
So, we will inject the PostgreSQL and Redis Services IP addresses manually using the parameters.
To get the Services IP addresses:

oc get svc postgresql redis
NAME         CLUSTER_IP     EXTERNAL_IP   PORT(S)    SELECTOR                                     AGE
postgresql   172.30.25.83   <none>        5432/TCP   app=postgresql,deploymentconfig=postgresql   1h
redis        172.30.198.140   <none>        6379/TCP   app=redis,deploymentconfig=redis             1h

Use these IP addresses to start the GitLab container, again by using the new-app command:
One important thing to note: You need to use the –name parameter and the name to anything else than gitlab otherwise all your OpenShift injected environment variables will be named GITLAB_* , and gitlab already uses some of those. In our case the variables will be name GITLAB_CE_* which fixes troubles.

oc new-app sameersbn/gitlab --name=gitlab-ce 
                             -e 'GITLAB_HOST=http://gitlab.apps.mycompany.com' \
                             -e 'DB_TYPE=postgres' -e 'DB_HOST=172.30.25.83' \ 
                             -e 'DB_PORT=5432'    -e 'DB_NAME=gitlab'   -e 'DB_USER=admin' \
                             -e 'DB_PASS=admin'   -e 'REDIS_HOST=172.30.198.140 -e 'REDIS_PORT=6379' \
                             -e 'GITLAB_SECRETS_DB_KEY_BASE=1234567890' -e 'SMTP_ENABLED=true' \
                             -e 'SMTP_HOST=smtp.mycompany.com' -e 'SMTP_PORT=25' \
                             -e 'GITLAB_EMAIL=no-reply@mycompany.com'
[...]
    Service "gitlab-ce" created
--> Success
    Run 'oc status' to view your app.

Of course, do not forget to add the volumes to make your repositories and logs persistent:

oc volumes dc/gitlab-ce --add --claim-name=gitlab-log --mount-path=/var/log/gitlab \
                     -t persistentVolumeClaim --overwrite
oc volumes dc/gitlab-ce --add --claim-name=gitlab-data --mount-path=/home/git/data \
                     -t persistentVolumeClaim --overwrite

A word on persistent volumes

The persistent volumes that you will have to create may require specific configuration: This is because both postgresql and postgres uses some hardcoded uid/gid and tries to make chown on some files.
If you are using NFS backed Persistent Volume, you will run into permission denied issues on chmod and chown.
To bypass this, you will have to add supplementalGroups in the DeploymentConfig’s SecurityContext:
– for postgres: add 26
– for gitlab-ce: add 1000

You will have then to create the tow persistent volumes and chown to those UID/GID and use all_squash option.


chown -R 26:26 /srv/nfs/pv0001
chow -R 1000:1000 /srv/nfs/pv0002

cat >> /etc/exports << EOF
/srv/nfs/pv0001 *(rw,all_squash)
/srv/nfs/pv0002 *(rw,all_squash)
EOF

exportfs -a

Create then your PV and PVC using the following definitions:

apiVersion: v1
kind: PersistentVolume
metadata:
  creationTimestamp: null
  name: pv0005
spec:
  accessModes:
  - ReadWriteOnce
  - ReadWriteMany
  capacity:
    storage: 8Gi
  claimRef:
    apiVersion: v1
    kind: PersistentVolumeClaim
    name: gitlab-data
    namespace: gitlab
  nfs:
    path: /srv/nfs/pv0005
    server: nfs-server.mycompany.com
  persistentVolumeReclaimPolicy: Retain
status: {}

And for the PVC:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  creationTimestamp: null
  name: gitlab-data
spec:
  accessModes:
  - ReadWriteOnce
  - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
status: {}

Now, you have your GitLab running in OpenShift on the URL http://gitlab.apps.mycompany.com ! enjoy

2 thoughts on “Deploy GitLab on OpenShift

  1. I notice you have two accessModes listed in your PVC.

    spec:
    accessModes:
    – ReadWriteOnce
    – ReadWriteMany

    Can you advise why? This would help me understand.

    I understand why you have both access modes defined within your PV but not in the PVC. I thought it would be one or the other?
    I guess i’m missing something in my reading/understanding.

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