fix: dynamically generate a tfvars file from github secrets

Author: yuzhoumo

.github/workflows/terraform.yml

@@ -30,29 +30,28 @@ jobs:
       with:
         cli_config_credentials_token: ${{ secrets.TF_API_TOKEN }}
 
+    # Create tfvars file
+    - name: Create Terraform variables file
+      run: |
+        cat > ./terraform/terraform.tfvars << EOF
+        admin_ssh_key = "${{ secrets.SSH_ADMIN_PUBKEY }}"
+        vultr_api_key = "${{ secrets.VULTR_API_KEY }}"
+        EOF
+
     # Initialize a new or existing Terraform working directory by creating initial files, loading any remote state, downloading modules, etc.
     - name: Terraform Init
-      run: |
-        terraform -chdir=./terraform init \
-          -var='admin_ssh_key=${{ secrets.SSH_ADMIN_PUBKEY }}' \
-          -var='vultr_api_key=${{ secrets.VULTR_API_KEY }}'
+      run: terraform -chdir=./terraform init
 
     # Checks that all Terraform configuration files adhere to a canonical format
     - name: Terraform Format
       run: terraform -chdir=./terraform fmt -check
 
     # Generates an execution plan for Terraform
     - name: Terraform Plan
-      run: |
-        terraform -chdir=./terraform plan -input=false \
-          -var='admin_ssh_key=${{ secrets.SSH_ADMIN_PUBKEY }}' \
-          -var='vultr_api_key=${{ secrets.VULTR_API_KEY }}'
+      run: terraform -chdir=./terraform plan -input=false
 
     # On push to "main", build or change infrastructure according to Terraform configuration files
     # Note: It is recommended to set up a required "strict" status check in your repository for "Terraform Cloud". See the documentation on "strict" required status checks for more information: https://help.github.com/en/github/administering-a-repository/types-of-required-status-checks
     - name: Terraform Apply
       if: github.ref == 'refs/heads/main' && github.event_name == 'push'
-      run: |
-        terraform -chdir=./terraform apply -auto-approve -input=false \
-          -var='admin_ssh_key=${{ secrets.SSH_ADMIN_PUBKEY }}' \
-          -var='vultr_api_key=${{ secrets.VULTR_API_KEY }}'
+      run: terraform -chdir=./terraform apply -auto-approve -input=false