feat(ci): Add terraform validation (#4)

Introduced a `.yml` file for a CI pipeline that validates the tf config.

fixes issue #2

.github/workflows/tf-validate.yml

@@ -0,0 +1,47 @@
+name: Terraform IaC template validation for Jenkins
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches: [master]
+  push:
+    branches: [master]
+
+jobs:
+  tf_validate:
+    runs-on: ubuntu-latest
+    name: Configure AWS `ghactions` IAM user
+    steps:
+      - uses: actions/checkout@v3
+      - name: Create Terraform variables
+        run: |
+          cd root && touch prod.tfvars
+          echo REGION=${{ secrets.AWS_REGION }} >> prod.tfvars
+          echo ENV=${{ secrets.ENV }} >> prod.tfvars
+          echo VPC_CIDR_BLOCK=${{ secrets.VPC_CIDR_BLOCK }} >> prod.tfvars
+          echo PUBLIC_ROUTE_TABLE_CIDR_BLOCK=${{ secrets.PUBLIC_ROUTE_TABLE_CIDR_BLOCK }} >> prod.tfvars
+          echo PUBLIC_SUBNETS=${{ secrets.PUBLIC_SUBNETS }} >> prod.tfvars
+          echo PRIVATE_SUBNETS=${{ secrets.PRIVATE_SUBNETS }} >> prod.tfvars
+
+      - name: Configure AWS Credentials
+        uses: aws-actions/configure-aws-credentials@v4
+        with:
+          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY }}
+          aws-secret-access-key: ${{ secrets.AWS_SECRET_KEY }}
+          aws-region: ${{ secrets.AWS_REGION }}
+
+      - name: Setup `Terraform`
+        uses: hashicorp/setup-terraform@v2
+
+      - name: Terraform fmt
+        id: fmt
+        run: terraform fmt -check
+        continue-on-error: true
+
+      - name: Terraform Init
+        id: init
+        run: terraform init
+
+      - name: Terraform Validate
+        id: validate
+        run: terraform validate

README.md

@@ -78,9 +78,15 @@ terraform -install-autocomplete
    terraform init
    ```
 
-2. Create a `.tfvars` from the `example.tfvars` template.
+2. Create a `<filename>.tfvars` using the `example.tfvars` template.
 
-3. Plan the cloud infrastructure
+3. Validate the terraform configuration
+
+   ```bash
+      terraform validate
+   ```
+
+4. Plan the cloud infrastructure
    This command shows how many resources will be created, deleted or modified when we run `terraform apply`.
 
    > NOTE: Remember to set your aws profile in the terminal to run the commands going forward
@@ -90,15 +96,15 @@ terraform -install-autocomplete
    terraform plan -var-file="<filename>.tfvars"
    ```
 
-4. Apply the changes/updates to the infrastructure to create it
+5. Apply the changes/updates to the infrastructure to create it
 
    ```bash
    # execute the tf plan
    # `--auto-approve` is to prevent tf from prompting you to say y/n to apply the plan
    terraform apply --auto-approve -var-file="<filename>.tfvars"
    ```
 
-5. To destroy your infrastructure, use the command:
+6. To destroy your infrastructure, use the command:
 
    ```bash
    terraform destroy --auto-approve -var-file="<filename>.tfvars"