How to deploy using Terraform
Terraform is an infrastructure automation tool to provision and manage resources in clouds or data centers. To deploy Charmed MySQL K8s using Terraform and Juju, you can use the Juju Terraform Provider.
The easiest way is to start from these examples of terraform modules prepared by Canonical. This page will guide you through a deployment using an example module for MySQL on Kubernetes.
For an in-depth introduction to the Juju Terraform Provider, read this Discourse post.
Note: Storage support was added in Juju Terraform Provider version 0.13+.
Summary
- Install Terraform tooling
- Verify the deployment
- Apply the deployment
- Check deployment status
- Clean up
Install Terraform tooling
This guide assumes Juju is installed and you have a K8s controller already bootstrapped. For more information, check the Set up the environment tutorial page.
Let’s install Terraform Provider and example modules:
sudo snap install terraform --classic
Switch to the K8s provider and create a new model:
juju switch microk8s
juju add-model my-model
Clone examples and navigate to the MySQL machine module:
git clone https://github.com/canonical/terraform-modules.git
cd terraform-modules/modules/k8s/mysql
Initialise the Juju Terraform Provider:
terraform init
Verify the deployment
Open the main.tf file to see the brief contents of the Terraform module:
resource "juju_application" "k8s_mysql" {
name = var.mysql_application_name
model = var.juju_model_name
trust = true
charm {
name = "mysql-k8s"
channel = var.mysql_charm_channel
}
units = 1
}
Run terraform plan to get a preview of the changes that will be made:
terraform plan -var "juju_model_name=my-model"
Apply the deployment
If everything looks correct, deploy the resources (skip the approval):
terraform apply -auto-approve -var "juju_model_name=my-model"
Check deployment status
Check the deployment status with
juju status --model k8s:my-model --watch 1s
Sample output:
Model Controller Cloud/Region Version SLA Timestamp
my-model k8s-controller microk8s/localhost 3.5.3 unsupported 12:37:25Z
App Version Status Scale Charm Channel Rev Address Exposed Message
mysql-k8s 8.0.36-0ubuntu0.22.04.1 active 1 mysql-k8s 8.0/stable 153 10.152.183.112 no
Unit Workload Agent Address Ports Message
mysql-k8s/0* active idle 10.1.77.76 Primary
Continue to operate the charm as usual from here or apply further Terraform changes.
Clean up
To keep the house clean, remove the newly deployed Charmed PostgreSQL by running
terraform destroy -var "juju_model_name=my-model"
Sample output:
juju_application.k8s_mysql: Refreshing state... [id=terra-k8s:mysql-k8s]
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
- destroy
Terraform will perform the following actions:
# juju_application.k8s_mysql will be destroyed
- resource "juju_application" "k8s_mysql" {
- constraints = "arch=amd64" -> null
- id = "terra-k8s:mysql-k8s" -> null
- model = "terra-k8s" -> null
- name = "mysql-k8s" -> null
- placement = "" -> null
- storage = [
- {
- count = 1 -> null
- label = "database-1" -> null
- pool = "kubernetes" -> null
- size = "1G" -> null
},
] -> null
- trust = true -> null
- units = 1 -> null
- charm {
- base = "ubuntu@22.04" -> null
- channel = "8.0/stable" -> null
- name = "mysql-k8s" -> null
- revision = 153 -> null
- series = "jammy" -> null
}
}
Plan: 0 to add, 0 to change, 1 to destroy.
Changes to Outputs:
- application_name = "mysql-k8s" -> null
Do you really want to destroy all resources?
Terraform will destroy all your managed infrastructure, as shown above.
There is no undo. Only 'yes' will be accepted to confirm.
Enter a value: yes
juju_application.k8s_mysql: Destroying... [id=terra-k8s:mysql-k8s]
juju_application.k8s_mysql: Destruction complete after 0s
Destroy complete! Resources: 1 destroyed.
For more examples of Terraform modules for K8s, see the other directories in the terraform-modules repository.
Feel free to contact us if you have any question and collaborate with us on GitHub!