Lab: Synthetic tests with Terraform and CI

What you will learn in this TP

• Create Synthetic tests with Terraform
• Understand assertions and locations
• Run a test in CI

Introduction #

What you will learn in this section

• Create Synthetic tests with Terraform
• Understand assertions and locations
• Run a test in CI

Context. The home page went down on a Sunday and nobody noticed before Monday. You set up versioned synthetic tests.

Prerequisites: Datadog account with API and application keys, Terraform  ·  Estimated time: 35 min

Synthetic tests managed as code.

Hands-on #

Guided steps, with their solution.

1. 1. Declare an API test

   Why? Versioned, the test is reviewed and recreated identically in every organisation.

   Write main.tf with an HTTP test on three locations.

2. 2. Add a certificate test

   Why? An expired certificate is a total outage, and entirely predictable.

   Add an SSL test that alerts 30 days before expiry.

3. 3. Apply

   Why? The provider reads the keys from environment variables.

   Apply the configuration and open the tests in Datadog.

4. 4. Trigger a failure

   Why? Check that an alert really fires, and only when it should.

   Change the status assertion target to 404, apply, and watch the result.

5. 5. Run in CI

   Why? Blocking a deployment that breaks a journey costs less than an incident.

   Run the test from the command line, as a CI pipeline would.

Difficulty level : ●●●○○ (3/5)