Table of Contents
This is the third post in the three post series about Kubernetes and GitLab. The first post can be found here: Edenmal - GitLab + Kubernetes: Perfect Match for Continuous Delivery with Container.
This post will not cover how to setup a Postgres and Redis server/cluster for the GitLab. In the near future I may even publish all my current manifests, that also contain Postgres and Redis server/cluster manifests.
If you don't have a Postgres and Redis, I would recommend you to check out the Kubernetes manifests at
sameersbn/docker-gitlab repo, here: https://github.com/sameersbn/docker-gitlab/tree/master/kubernetes They contain a manifest for Postgres and Redis server.
Decision to use
sameersbn GitLab image instead of the official
The manifests below are using
sameersbn/docker-gitlab image. You may ask “Why not use the official GitLab image?".
A good question, the answer to that lies in the concept of configuration of GitLab inside the container.
I personally prefer an image that doesn't need a persistent volume for the configuration.
Only time I want to use a persistent volume, is when I have data from an application that needs to persistence.
Last time I looked a the official GitLab Docker image I was required to have a persistent volume for the configuration.
That is not how I imagine an application in a container to be configured. I prefer:
- Configuration through environment variables
- ONE “small” configuration (fitting into a Kubernetes ConfigMap)
- Configuration by flag
Having to “move” around a persistent volume which contains the config is a bad thing from my point of view.
That is the reason behind why I am using
sameersbn/docker-gitlab image instead of the official
Additionally there are some other smaller points, for example what runs in the container is more than should. At best one process per container.
- Kubernetes cluster with Ingress support
- Kubernetes Ingress Controller (example: nginx-ingress controller)
- StorageClass configured in Kubernetes
ReadWriteManyPersistent Storage (example CephFS using Rook)
- Domain/Subdomain ready to be used for the GitLab
kubectlbinary (with Kubernetes cluster access)
- Postgres server for GitLab
- Redis server/cluster for GitLab
NOTE Postgres and Redis need to be reachable from inside the Kubernetes cluster.
The manifests shown in this blog post will also be available on GitHub here: GitHub - galexrt/kubernetes-manifests. If you want the latest manifests version, I recommend you checkout the repository (though I try to keep the blog post and repository in the same state/version).
Step 1 - Verify Kubernetes cluster “connectivity”
To check if you have proper Kubernetes cluster connection, run the following command:
cluster-infoshows you if you can connect to the cluster and list the available cluster services (in the ouput: Kubernetes apiserver and KubeDNS service).
Step 2 - Write Kubernetes manifests for GitLab
As written in the Intro, the manifests will cover only the GitLab.
The list of all available environment variables for the configuration, can be found here: sameersbn/docker-gitlab - Available Configuration Parameters. If you have a variable that would contain a password or token, put it in the Secret manifest below.
The values for the
data keys, need to be
This can be done from the command line on most Linuxes using the
base64 command. Like this:
base64wrapping after specific length per line) In the manifest below there are variables beginning with
__YOUR_...__, you need to replace those.
__YOUR_GITLAB_SECRETS_variables should be replaced by
base64encoded randomly generated strings.
__YOUR_DB_PASS__should be replaced by
base64encoded Postgres database server password.
__YOUR_SMTP_PASS__should be replaced by
base64encoded SMTP server password.
__YOUR_GITLAB_ROOT_PASSWORD__should be replaced by
base64encoded chosen first GitLab user
rootpassword of your choice.
The manifest looks like this:
StatefulSet contains the image used and what is not often used
envFrom uses a list of “references” to ConfigMaps and Secrets and puts them as environment variables into the Pod.
envFrom has one disadvantage, when updating a ConfigMap or Secret referenced, the Pod doesn't get “updated”/recreated.
Depending on how you look at rolling out software every change to a ConfigMap and Secret can be considered a version change aka updating the object to trigger update of the Pods.
You need to replace
__STORAGE_CLASS__ with the available StorageClass in your Kubernetes cluster.
This Service is for the Ingress to be able to reach the GitLab.
To be able to reach the GitLab from outside the cluster over your Ingress controller of choice.
The Ingress requires the Service created in Service.
You need to replace
__INGRESS_CLASS__ with your in cluster configured Ingress controller.
Step 3 - Create the manifests
You can either a) save all manifests in one file, but then separated by
--- or b) per manifest on file.
To create/run the mnaifests on Kubernetes, you can now go ahead an run:
FILE_NAMEis the name of the file containing the mnaifest(s). If the command I suggest you take a look at the line which
kubectltold you the error is.
Step 4 - Login to your new GitLab
If everything was successfull, you should be able to see your GitLab instance in, depending on the server network bandwith and GitLab database setup speed, about 10-15 minutes.
You should then be able to login to your GitLab over the domain name you used in the Ingress manifest.
With the example values above the address would be
The login information for the first “root” user is:
base64decoded value chosen in Secret - GITLAB_ROOT_PASSWORD
I hope this gives a good idea on how to run GitLab on Kubernetes or even simply a starting point for extending/customizing the manifests for your needs. Another starting point that also contains manifests for a single Postgres and Redis server, can be found here: https://github.com/sameersbn/docker-gitlab/tree/master/kubernetes.