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A Terraform module for creating Jenkins X infrastructure on Google Cloud

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Jenkins X GKE Module

Terraform Version

NOTE: While the required minimum Terraform version is 0.12.0, automated CI tests are performed with 0.13 only. The only expected compatibility issues to be aware of are around provider requirements. For more information see here


This repo contains a Terraform module for provisioning a Kubernetes cluster for Jenkins X on Google Cloud.

What is a Terraform module

A Terraform "module" refers to a self-contained package of Terraform configurations that are managed as a group. For more information around modules refer to the Terraform documentation.

How do you use this module

Prerequisites

To make use of this module, you need a Google Cloud project. Instructions on how to setup such a project can be found in the Google Cloud Installation and Setup guide. You need your Google Cloud project id as an input variable for using this module.

You also need to install the Cloud SDK, in particular gcloud. You find instructions on how to install and authenticate in the Google Cloud Installation and Setup guide as well.

Once you have gcloud installed, you need to create Application Default Credentials by running:

gcloud auth application-default login

Alternatively, you can export the environment variable GOOGLE_APPLICATION_CREDENTIALS referencing the path to a Google Cloud service account key file.

Last but not least, ensure you have the following binaries installed:

  • gcloud
  • kubectl ~> 1.14.0
    • kubectl comes bundled with the Cloud SDK
  • terraform ~> 0.12.0
    • Terraform installation instruction can be found here

Cluster provisioning

A default Jenkins X ready cluster can be provisioned by creating a file main.tf in an empty directory with the following content:

module "jx" {
  source  = "jenkins-x/jx/google"

  gcp_project = "<my-gcp-project-id>"
}

output "jx_requirements" {
  value = module.jx.jx_requirements
}  

You can then apply this Terraform configuration via:

terraform init
terraform apply

This creates a cluster within the specified Google Cloud project with all possible configuration options defaulted.

⚠️ Note: This example is for getting up and running quickly. It is not intended for a production cluster. Refer to Production cluster considerations for things to consider when creating a production cluster.

On completion of terraform apply a jx_requirements output is available which can be used as input to jx boot. Refer to Running jx boot for more information.

In the default configuration, no custom domain is used. DNS resolution occurs via nip.io. For more information on how to configure and use a custom domain, refer to Using a custom domain.

If you just want to experiment with Jenkins X, you can set force_destroy to true. This allows you to remove all generated resources when running terraform destroy, including any generated buckets including their content.

The following two paragraphs provide the full list of configuration and output variables of this Terraform module.

Inputs

Name Description Type Default Required
apex_domain The parent / apex domain to be used for the cluster string "" no
apex_domain_gcp_project The GCP project the apex domain is managed by, used to write recordsets for a subdomain if set. Defaults to current project. string "" no
apex_domain_integration_enabled Flag that when set attempts to create delegation records in apex domain to point to domain created by this module bool true no
bucket_location Bucket location for storage string "US" no
cluster_location The location (region or zone) in which the cluster master will be created. If you specify a zone (such as us-central1-a), the cluster will be a zonal cluster with a single cluster master. If you specify a region (such as us-west1), the cluster will be a regional cluster with multiple masters spread across zones in the region string "us-central1-a" no
cluster_name Name of the Kubernetes cluster to create string "" no
cluster_network The name of the network (VPC) to which the cluster is connected string "default" no
cluster_subnetwork The name of the subnetwork to which the cluster is connected. Leave blank when using the 'default' vpc to generate a subnet for your cluster string "" no
create_ui_sa Whether the service accounts for the UI should be created bool true no
dev_env_approvers List of git users allowed to approve pull request for dev enviornment repository list(string) [] no
enable_backup Whether or not Velero backups should be enabled bool false no
enable_private_endpoint (Beta) Whether the master's internal IP address is used as the cluster endpoint. Requires VPC-native bool false no
enable_private_nodes (Beta) Whether nodes have internal IP addresses only. Requires VPC-native bool false no
force_destroy Flag to determine whether storage buckets get forcefully destroyed bool false no
gcp_project The name of the GCP project to use string n/a yes
git_owner_requirement_repos The git id of the owner for the requirement repositories string "" no
gsm Enables Google Secrets Manager, not available with JX2 bool false no
ip_range_pods The IP range in CIDR notation to use for pods. Set to /netmask (e.g. /18) to have a range chosen with a specific netmask. Enables VPC-native string "" no
ip_range_services The IP range in CIDR notation use for services. Set to /netmask (e.g. /21) to have a range chosen with a specific netmask. Enables VPC-native string "" no
jenkins_x_namespace Kubernetes namespace to install Jenkins X in string "jx" no
jx2 Is a Jenkins X 2 install bool true no
jx_bot_token Bot token used to interact with the Jenkins X cluster git repository string "" no
jx_bot_username Bot username used to interact with the Jenkins X cluster git repository string "" no
jx_git_operator_version The jx-git-operator helm chart version string "0.0.192" no
jx_git_url URL for the Jenins X cluster git repository string "" no
kuberhealthy Enables Kuberhealthy helm installation bool true no
lets_encrypt_production Flag to determine wether or not to use the Let's Encrypt production server. bool true no
master_authorized_networks List of master authorized networks. If none are provided, disallow external access (except the cluster node IPs, which GKE automatically allowlists). list(object({ cidr_block = string, display_name = string })) [] no
master_ipv4_cidr_block The IP range in CIDR notation to use for the hosted master network. This range must not overlap with any other ranges in use within the cluster's network, and it must be a /28 subnet string "10.0.0.0/28" no
max_node_count Maximum number of cluster nodes number 5 no
max_pods_per_node Max gke nodes = 2^($CIDR_RANGE_PER_NODE-$POD_NETWORK_CIDR) (see gke docs) number 64 no
min_node_count Minimum number of cluster nodes number 3 no
node_disk_size Node disk size in GB string "100" no
node_disk_type Node disk type, either pd-standard or pd-ssd string "pd-standard" no
node_machine_type Node type for the Kubernetes cluster string "n1-standard-2" no
node_preemptible Use preemptible nodes bool false no
node_spot Use spot nodes bool false no
parent_domain **Deprecated** Please use apex_domain variable instead.r string "" no
parent_domain_gcp_project **Deprecated** Please use apex_domain_gcp_project variable instead. string "" no
release_channel The GKE release channel to subscribe to. See https://cloud.google.com/kubernetes-engine/docs/concepts/release-channels string "REGULAR" no
resource_labels Set of labels to be applied to the cluster map(any) {} no
subdomain Optional sub domain for the installation string "" no
tls_email Email used by Let's Encrypt. Required for TLS when apex_domain is specified string "" no
vault_url URL to an external Vault instance in case Jenkins X shall not create its own system Vault string "" no
velero_namespace Kubernetes namespace for Velero string "velero" no
velero_schedule The Velero backup schedule in cron notation to be set in the Velero Schedule CRD (see default-backup.yaml) string "0 * * * *" no
velero_ttl The the lifetime of a velero backup to be set in the Velero Schedule CRD (see default-backup.yaml) string "720h0m0s" no
version_stream_ref The git ref for version stream to use when booting Jenkins X. See https://jenkins-x.io/docs/concepts/version-stream/ string "master" no
version_stream_url The URL for the version stream to use when booting Jenkins X. See https://jenkins-x.io/docs/concepts/version-stream/ string "https://github.com/jenkins-x/jenkins-x-versions.git" no
webhook Jenkins X webhook handler for git provider string "lighthouse" no
zone Zone in which to create the cluster (deprecated, use cluster_location instead) string "" no

Outputs

Name Description
backup_bucket_url The URL to the bucket for backup storage
cluster_location The location of the created Kubernetes cluster
cluster_name The name of the created Kubernetes cluster
connect The cluster connection string to use once Terraform apply finishes
externaldns_dns_name ExternalDNS name
externaldns_ns ExternalDNS nameservers
gcp_project The GCP project in which the resources got created
jx_requirements The jx-requirements rendered output
log_storage_url The URL to the bucket for log storage
report_storage_url The URL to the bucket for report storage
repository_storage_url The URL to the bucket for artifact storage
tekton_sa_email The Tekton service account email address, useful to provide further IAM bindings
tekton_sa_name The Tekton service account name, useful to provide further IAM bindings
vault_bucket_url The URL to the bucket for secret storage

Running jx boot

A terraform output (jx_requirements) is available after applying this Terraform module.

terraform output jx_requirements

This jx_requirements output can be used as input to Jenkins X Boot which is responsible for installing all the required Jenkins X components into the cluster created by this module.

Jenkins X Installation/Update Flow

⚠️ Note: The generated jx-requirements is only used for the first run of jx boot. During this first run of jx boot a git repository containing the source code for Jenkins X Boot is created. This (new) repository contains a jx-requirements.yml (which is now ahead of the jx-requirements output from terraform) used by successive runs of jx boot.

Execute:

terraform output jx_requirements > <some_empty_dir>/jx-requirements.yml
# jenkins-x creates the environment repository directory localy before pushing to the Git server of choice
cd <some_empty_dir>
jx boot --requirements jx-requirements.yml

You are prompted for any further required configuration. The number of prompts depends on how much you have pre-configured via your Terraform variables.

Using a custom domain

If you want to use a custom domain with your Jenkins X installation, you need to provide values for the variables apex_domain and tls_email. apex_domain is the fully qualified domain name you want to use and tls_email is the email address you want to use for issuing Let's Encrypt TLS certificates.

Before you apply the Terraform configuration, you also need to create a Cloud DNS managed zone, with the DNS name in the managed zone matching your custom domain name, for example in the case of example.jenkins-x.rocks as domain:

Creating a Managed Zone

When creating the managed zone, a set of DNS servers get created which you need to specify in the DNS settings of your DNS registrar.

DNS settings of Managed Zone

It is essential that before you run jx boot, your DNS servers settings are propagated, and your domain resolves. You can use DNS checker to check whether your domain settings have propagated.

When a custom domain is provided, Jenkins X uses ExternalDNS together with cert-manager to create A record entries in your managed zone for the various exposed applications.

If apex_domain id not set, your cluster will use nip.io in order to create publicly resolvable URLs of the form http://<app-name>-<environment-name>.<cluster-ip>.nip.io.

Production cluster considerations

The configuration as seen in Cluster provisioning is not suited for creating and maintaining a production Jenkins X cluster. The following is a list of considerations for a production usecase.

  • Specify the version attribute of the module, for example:

    module "jx" {
      source  = "jenkins-x/jx/google"
      version = "1.2.4"
      # insert your configuration
    }
    
    output "jx_requirements" {
     value = module.jx.jx_requirements
    }

    Specifying the version ensures that you are using a fixed version and that version upgrades cannot occur unintented.

  • Keep the Terraform configuration under version control, by creating a dedicated repository for your cluster configuration or by adding it to an already existing infrastructure repository.

  • Setup a Terraform backend to securely store and share the state of your cluster. For more information refer to Configuring a Terraform backend.

Configuring a Terraform backend

A "backend" in Terraform determines how state is loaded and how an operation such as apply is executed. By default, Terraform uses the local backend which keeps the state of the created resources on the local file system. This is problematic since sensitive information will be stored on disk and it is not possible to share state across a team. When working with Google Cloud a good choice for your Terraform backend is the gcs backend which stores the Terraform state in a Google Cloud Storage bucket. The examples directory of this repository contains configuration examples for using the gcs backed with and without optionally configured customer supplied encryption key.

To use the gcs backend you will need to create the bucket upfront. You can use gsutil to create the bucket:

gsutil mb gs://<my-bucket-name>/

It is also recommended to enable versioning on the bucket as an additional safety net in case of state corruption.

gsutil versioning set on gs://<my-bucket-name>

You can verify whether a bucket has versioning enabled via:

gsutil versioning get gs://<my-bucket-name>

FAQ

How do I get the latest version of the terraform-google-jx module

terraform init -upgrade

How to I specify a specific google provider version

provider "google" {
  version = "~> 2.12.0"
  project = var.gcp_project
}

provider "google-beta" {
  version = "~> 2.12.0"
  project = var.gcp_project
}

Why do I need Application Default Credentials

The recommended way to authenticate to the Google Cloud API is by using a service account. This allows for authentication regardless of where your code runs. This Terraform module expects authentication via a service account key. You can either specify the path to this key directly using the GOOGLE_APPLICATION_CREDENTIALS environment variable or you can run gcloud auth application-default login. In the latter case gcloud obtains user access credentials via a web flow and puts them in the well-known location for Application Default Credentials (ADC), usually ~/.config/gcloud/application_default_credentials.json.

Development

Releasing

At the moment there is no release pipeline defined in jenkins-x.yml. A Terraform release does not require building an artifact, only a tag needs to be created and pushed. To make this task easier and there is a helper script release.sh which simplifies this process and creates the changelog as well:

./scripts/release.sh

This can be executed on demand whenever a release is required. For the script to work the envrionment variable $GH_TOKEN must be exported and reference a valid GitHub API token.

How do I contribute

Contributions are very welcome! Check out the Contribution Guidelines for instructions.

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