feat: Adding Terraform module for UPF (#89)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,39 @@
+---
+name: Bug report
+about: Create a bug report to help us improve
+title: ""
+labels: ["bug"]
+assignees: ''
+---
+
+#### Describe the bug
+<!-- A clear and concise description of what the bug is. -->
+
+#### To Reproduce
+<!-- Steps that can be taken to reproduce the behaviour -->
+
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+#### Expected behavior
+<!-- A clear and concise description of what you expected to happen. -->
+
+#### Screenshots
+<!-- If applicable, add screenshots to help explain your problem. -->
+
+#### Logs
+<!-- If applicable, add logs to help explain your problem. -->
+
+#### Environment
+
+- Charm / library version (if relevant): <!-- e.g. 1.2 -->
+- Juju version (output from `juju --version`):
+- Cloud Environment: <!-- e.g. GKE -->
+- Kubernetes version (output from `kubectl version --short`):
+- Terraform version (output from `terraform version`):
+
+#### Additional context
+
+<!-- Add any other context about the problem here. -->

.github/workflows/main.yaml

@@ -19,6 +19,9 @@ jobs:
   static-analysis:
     uses: canonical/sdcore-github-workflows/.github/workflows/static-analysis.yaml@main
 
+  terraform-check:
+    uses: canonical/sdcore-github-workflows/.github/workflows/terraform.yaml@main
+
   unit-tests-with-coverage:
     uses: canonical/sdcore-github-workflows/.github/workflows/unit-test.yaml@main
 

terraform/README.md

@@ -0,0 +1,100 @@
+# SD-Core UPF K8s Terraform Module
+
+This folder contains a base [Terraform][Terraform] module for the sdcore-gnbsim-k8s charm.
+
+The module uses the [Terraform Juju provider][Terraform Juju provider] to model the charm
+deployment onto any Kubernetes environment managed by [Juju][Juju].
+
+The module can be used to deploy the UPF separately as well as a part of a higher level module,
+depending on the deployment architecture.
+
+## Module structure
+
+- **main.tf** - Defines the Juju application to be deployed.
+- **variables.tf** - Allows customization of the deployment. Except for exposing the deployment
+  options (Juju model name, channel or application name) also allows overwriting charm's default
+  configuration.
+- **output.tf** - Responsible for integrating the module with other Terraform modules, primarily
+  by defining potential integration endpoints (charm integrations), but also by exposing
+  the application name.
+- **terraform.tf** - Defines the Terraform provider.
+
+## Deploying sdcore-upf-k8s base module separately
+
+### Pre-requisites
+
+- A Kubernetes host with a CPU supporting AVX2 and RDRAND instructions (Intel Haswell, AMD Excavator or equivalent)
+- A Kubernetes cluster with the Multus addon enabled.
+- Juju 3.x
+- Juju controller bootstrapped onto the K8s cluster
+- Terraform
+
+### Deploying UPF with Terraform
+
+Clone the `sdcore-upf-k8s-operator` Git repository.
+
+From inside the `terraform` folder, initialize the provider:
+
+```shell
+terraform init
+```
+
+Create Terraform plan:
+
+```shell
+terraform plan
+```
+
+While creating the plan, the default configuration can be overwritten with `-var-file`. To do that,
+Terraform `tfvars` file should be prepared prior to the plan creation.
+
+Deploy UPF:
+
+```console
+terraform apply -auto-approve 
+```
+
+### Cleaning up
+
+Destroy the deployment:
+
+```shell
+terraform destroy -auto-approve
+```
+
+## Using sdcore-upf-k8s base module in higher level modules
+
+If you want to use `sdcore-upf-k8s` base module as part of your Terraform module, import it
+like shown below:
+
+```text
+module "upf" {
+  source = "git::https://github.com/canonical/sdcore-upf-k8s-operator//terraform"
+  
+  model_name = "juju_model_name"
+  config = Optional config map
+}
+```
+
+Create integrations, for instance:
+
+```text
+resource "juju_integration" "upf-prometheus" {
+  model = var.model_name
+  application {
+    name     = module.upf.app_name
+    endpoint = module.upf.metrics_endpoint
+  }
+  application {
+    name     = module.prometheus.app_name
+    endpoint = module.prometheus.metrics_endpoint
+  }
+}
+```
+
+The complete list of available integrations can be found [here][upf-integrations].
+
+[Terraform]: https://www.terraform.io/
+[Terraform Juju provider]: https://registry.terraform.io/providers/juju/juju/latest
+[Juju]: https://juju.is
+[upf-integrations]: https://charmhub.io/sdcore-upf-k8s/integrations

terraform/main.tf

@@ -0,0 +1,15 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+resource "juju_application" "upf" {
+  name  = var.app_name
+  model = var.model_name
+
+  charm {
+    name    = "sdcore-upf-k8s"
+    channel = var.channel
+  }
+  config = var.config
+  units  = 1
+  trust  = true
+}

terraform/outputs.tf

@@ -0,0 +1,24 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+output "app_name" {
+  description = "Name of the deployed application."
+  value       = juju_application.upf.name
+}
+
+# Provided integration endpoints
+
+output "metrics_endpoint" {
+  description = "Exposes the Prometheus metrics endpoint providing telemetry about the UPF instance."
+  value = "metrics-endpoint"
+}
+
+output "fiveg_n3_endpoint" {
+  description = "Name of the endpoint used to provide information on connectivity to the N3 plane."
+  value = "fiveg_n3"
+}
+
+output "fiveg_n4_endpoint" {
+  description = "Name of the endpoint used to provide information on connectivity to the N4 plane."
+  value = "fiveg_n4"
+}

terraform/terraform.tf

@@ -0,0 +1,11 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+terraform {
+  required_providers {
+    juju = {
+      source  = "juju/juju"
+      version = "~> 0.10.1"
+    }
+  }
+}

terraform/variables.tf

@@ -0,0 +1,26 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+variable "model_name" {
+  description = "Name of Juju model to deploy application to."
+  type        = string
+  default     = ""
+}
+
+variable "app_name" {
+  description = "Name of the application in the Juju model."
+  type        = string
+  default     = "upf"
+}
+
+variable "channel" {
+  description = "The channel to use when deploying a charm."
+  type        = string
+  default     = "1.3/edge"
+}
+
+variable "config" {
+  description = "Application config. Details about available options can be found at https://charmhub.io/sdcore-upf-k8s-operator/configure."
+  type        = map(string)
+  default     = {}
+}