Running Terraform Plan Locally
Whilst it is possible to see the results of a Terraform plan when you create a pull request, it is also possible to run a Terraform plan locally. Some engineers prefer this as it provides a quicker feedback loop to identify any issues with your infrastructure code.
Enter your AWS SSO credentials
Get your AWS SSO credentials as detailed here, choose option 1 and paste the credentials into the terminal window you are working from.
Please note that the credentials will expire after a period of 1 hour.
Install Terraform
Follow the instructions here to install the latest version of Terraform according to your platform.
Retrieve the Modernisation Platform account ID
You will need the Modernisation Platform account ID to assume the correct role when running terraform init.
You can retrieve the Modernisation Platform account ID from the SSM Parameter store via the web console, or via CLI.
This will allow you to assume the correct role_arn.
aws ssm get-parameters --region eu-west-2 \
--names "modernisation_platform_account_id" --with-decryption --query "Parameters[*].{Value:Value}" --output text
Run Terraform plan
- Navigate to your application infrastructure code -
cd modernisation-platform-environments/terraform/environments/my-application - Run a Terraform init that assumes the backend role in the Modernisation Platform account -
terraform init -backend-config=assume_role={role_arn=\"arn:aws:iam::000000000000:role/modernisation-account-terraform-state-member-access\"}
Remember to replace the
000000000000placeholder with the Modernisation Platform account ID.
- View the workspaces (you have different workspaces for your different environment accounts) -
terraform workspace list - Select the required workspace -
terraform workspace select my-application-development - Run a Terraform plan -
terraform plan
Running a plan locally has read only permissions, you will not be able to run an apply, destroy or import. The example syntax for assuming a backend role is appropriate for Terraform
1.6.0onwards.