GitLab provides a built-in Kubernetes Integration that allows you to build, test, deploy, and run your app at scale.
In this tutorial you will learn how to use the gitlab
Kubernetes integration using a Scaleway Virtual Instance. The instance will be deployed using the Scaleway gitlab
InstantApp.
Requirements
- You have deployed a Virtual Instance running the
gitlab
InstantApp (follow this tutorial to deploy it)- An already deployed Kapsule cluster.
- You have downloaded the corresponding kubeconfig file and kubectl is working
- Helm client installed
In this tutorial we use helm
to deploy a gitlab
runner on a Kapsule
cluster. If you do not know how to install helm
, please follow the tutorial on the official helm
website.
On the example below we have successfully installed helm
version 3.2.0
$ helm version
version.BuildInfo{Version:"v3.2.0", GitCommit:"e11b7ce3b12db2941e90399e874513fbd24bcb71", GitTreeState:"clean", GoVersion:"go1.13.10"}
The helm
charts are provided through repositories. By default helm
3 does not have any repository configured. We will add the gitlab
repository, as it provides the necessary chart to install the runner.
$ helm repo add gitlab https://charts.gitlab.io
"gitlab" has been added to your repositories
$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "gitlab" chart repository
Update Complete. ⎈ Happy Helming!⎈
A helm
chart is always shipped with a value.yaml
file. It can be edited to customize the deployement of the application. In this part of the tutorial we customize the value.yaml
to fit our needs and deploy the runner on kapsule
.
1 .Get the value.yaml :
$ wget https://gitlab.com/gitlab-org/charts/gitlab-runner/-/raw/master/values.yaml
Each gitlab
runner needs a registration token to register on the gitlab
server. Retrieve the registration token from the GitLab web interface (“Admin Area” > “Runners”):
2 . Fill the value.yaml
with :
http://212.47.237.92/
)rbac
Note: by default, the gitlabUrl and the registration token lines are written out as a comment in the
values.yaml
file. Make sure you have deleted the#
before saving.
[..]
gitlabUrl: http://212.47.237.92/
runnerRegistrationToken: "t7u_qjh3EFJX2-yPypkz"
rbac:
create: true
[..]
serviceAccountName: default
We will use a dedicated namespace.
3 . To install the gitlab
runner, create it on your Kapsule
cluster:
$ kubectl create ns gitlab-runner
namespace/gitlab-runner created
The default service account should use a new kubernetes role, and rolebinding.
4 . Use the following example to create a role and role binding and associate it to the default service account in the gitlab-runner
namespace :
$ cat <<EOF | kubectl create -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
name: gitlab-runner
namespace: gitlab-runner
rules:
- apiGroups: [""]
resources: ["pods"]
verbs: ["list", "get", "watch", "create", "delete"]
- apiGroups: [""]
resources: ["pods/exec"]
verbs: ["create"]
- apiGroups: [""]
resources: ["pods/log"]
verbs: ["get"]
EOF
$ kubectl create rolebinding --namespace=gitlab-runner gitlab-runner-binding --role=gitlab-runner --serviceaccount=gitlab-runner:default
5 . Use the helm
command to install the runner (note that you specify in this command line the values.yaml
file) :
$ helm install --namespace gitlab-runner gitlab-runner -f ./values.yaml gitlab/gitlab-runner
NAME: gitlab-runner
LAST DEPLOYED: Wed May 6 15:48:20 2020
NAMESPACE: gitlab-runner
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Your GitLab Runner should now be registered against the GitLab instance reachable at: "http://212.47.237.92/"
You can check the runner is working ok in the gitlab
console (“admin area” > runners):
To demonstrate if the runner is working, we create a repository with a “hello world” piece of code written in python.
1 . Create the files using a text editor of your choice (e.g. nano
or vim
). In this tutorial, we use nano
.
nano helloworld.py
2 . Create the content of the file as follows, save and exit:
print("Hello, World!")
3 . Create an associated gitlab-ci file to check it is running in the runner we just deployed:
nano .gitlab-ci.yaml
4 . Create the content of the file as follows, save and exit:
image: ubuntu
hello-test:
script:
- apt-get update && apt-get install python3
- python3 helloworld.py
5 . Push the repository and an ubuntu container is launched. At first apt
is updated and python3
is installed, and then the “hello, world” script is launched in the terminal.
If you want to learn more about running a gitlab
runner on Kubernetes you can also check the gitlab-ci
official documentation