Jenkins X is a reimagined CI/CD implementation for the cloud which is heavily influenced by the State of DevOps reports, and more recently the book, Accelerate: The Science of Lean Software and DevOps by Nicole Forsgren, Jez Humble and Gene Kim, summarized in this blog post.
This post will show you how to use Jenkins X to create a GitOps managed install of Jenkins X using CloudBees CodeShip and HashiCorp’s Terraform on GKE with a single command, and, make changes to that environment via GitOps.
GitOps is a great way of managing cloud environments. By ensuring all changes originate from a Git commit, we have fa ull audit trail into all changes made to an environment. This approach also gives us the added benefit of being able to reconstruct an environment from its git history, reducing MTTR. For more information on using GitOps as a method of delivery, see the Weave Works Blog.
Before you start
Some of the commands that are shown here are recent additions to the Jenkins-X CLI. To make use of these you’ll need to be on a fairly recent version of jx. I’m using:
jx --version 1.3.145
If you need to upgrade the version of jx, you can use jx upgrade cli, or for a new installation follow the guide.
You’ll also need a Google Cloud Account, you can sign up for a free account which entitles you to $300 of spend over a 12 month period. The default quotas for the trial account are just enough to create a very minimal GKE cluster.
The magic command…
jx create codeship
Whilst you can run this without any parameters, we’re going to supply an organisation name rather than allowing jx to generate one for us.
jx create codeship -o codeship
This will perform three things:
1. Create a GCP service account
Firstly, in order to administer the cluster, jx will create a Service Account on GCP. We want to do this to ensure that the administration of the cluster is done with the minimum privilege possible. You can do this via the GCP console or via the gcloud cli tool, or you could use the jx create gke-service-account helper command.
- Validate you have enough permissions to create a new service account
- If the account doesn’t already exist, create a service account called codeship
- Assign the appropriate permissions
- Create a service account key
- Download the key to your home directory to a file called codeship.key.json
2. Create the organisation repository and Terraform scripts
The second step that jx performs is to create the organisation repository (we’ll use GitHub for this) that contains all of the Terraform configuration for the environment. In your home directory, a .jx folder will be created if it doesn’t already exist and within that, you’ll see the organisations directory with the newly created organisation-codeship and its Terraform configuration.
A terraform.tfvars will be created and populated with the values supplied during the install such as ‘Minimum Number of Nodes’, ‘Cluster Name’ etc.
✔ ~/.jx $ tree organisations/organisation-codeship/ organisations/organisation-codeship/ ├── README.md ├── build.sh <- build/deploy script that codeship calls └── clusters └── dev <- cluster definition └── terraform ├── README.md ├── main.tf <- main terraform cluster config file ├── output.tf ├── terraform.tf ├── terraform.tfvars <- terraform variable file for customisation └── variables.tf 3 directories, 8 files ✔ ~/.jx
The configuration files listed above can all be modified to tailor your cluster configuration to your needs.
3. Create the CloudBees CodeShip build and trigger the deployment
Once the Terraform scripts have been created and pushed back up to the remote organisation-codeship repo, a CloudBees CodeShip project & build will be created to trigger from any changes to this repository. jx will prompt you for your CloudBees CodeShip login details. These details will not be stored anywhere and are only used to login to the CloudBees CodeShip v2 API behind the scenes. This post assumes you already have a CloudBees CodeShip account setup. If you don’t have a CloudBees CodeShip account, you can setup a free one here.
If you login to the CloudBees CodeShip user interface, you will see the newly created project:
By clicking on that, you will see the build is in progress. To create a fresh cluster and install jx normally takes around 10-15 minutes the first time it is run. When it’s complete, it should look something like the screenshot below:
You now have a working environment deployed by Terraform and CloudBees CodeShip. By expanding the ./build.sh section of the build, you will be able to see the generated admin password and URLs needed to login to the environment.
Making a ‘safe’ change
Now that we have a cluster deployed with Jenkins X installed and running, we can use GitOps to manage changes to the cluster.
To start off we going to make a “safe change” to the cluster. A safe change is one that does not result in any destructive behavior when being applied by Terraform. In this example, we are going to change the auto scaling parameters for a default node pool.
- Clone the organisation repository locally
- Create a local branch to work on git branch -b autoscaling
- Edit clusters/dev/terraform.tfvars, change max_node_count to a new value
- Commit the change and push to the autoscaling branch with git push origin autoscaling
- Create a pull-request with hub pull-request
Although CloudBees CodeShip does not (currently) build pull requests on forked repositories, it will notice the new commit on the branch and attempt to validate the change is non destructive. Feedback will be posted to the PR in GitHub stating whether it can be safely merged.
When the PR is merged, CloudBees CodeShip will trigger the deployment and apply the required changes to the cluster.
Making a ‘destructive’ change
Lets try the same again, except this time we will change something that will force the creation of a new resource, such as renaming the cluster. For a full list of available options see the Terraform documentation.
- Create a new local branch to work on git branch -b rename-cluster
- Edit clusters/dev/terraform.tfvars, change cluster_name to a new value
- Commit the change and push to the rename-cluster branch with git push origin rename-cluster
- Create a pull-request with hub pull-request
CloudBees CodeShip will attempt to validate that the PR does not contain any destructive Terraform plans, in this instance it should fail and post feedback, stopping a merge, to the the PR on GitHub.
Fancy a closer look?
James Rawlings, James Strachan and Rob Davies are going to be presenting and running workshops at DevOps World | Jenkins World. They’ll also be hanging out at the Jenkins X demo area so come and say hello and see what’s the latest cool and exiting things to come out of Jenkins X. Use *JWFOSS* for 30% discount off registration
Want to get involved?
Jenkins X is open source, the community mainly hangs out in the Jenkins X Kubernetes Slack channels and for tips on being more involved with Jenkins X take a look at our contributing docs. We’ve been helping lots of folks get into open source, learn new technologies and languages like golang. Why not get involved?