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Last updated: 25 Aug 2023

Update an application’s environment configuration

This tutorial aims to guide you through the process of updating an applications configuration in the govuk-helm-charts repository. You will be updating the configuration of an example test app, deploy and verify your changes.

The govuk-helm-chart repository contains configuration for how an app is deployed into an environment, for example CPU and memory allocation for pods, environment variable values, health check configuration etc.

1. Update the example test app configuration

   1. Clone the govuk-helm-charts repository.
   2. Create a new branch to add your changes.
   3. Locate the govuk-replatform-test-app values in govuk-helm-charts repository. (Please note that app-config/ci/integration-values.yml is symlinked to values-integration.yaml, you just need to make changes in one of the files.)
   4. Add your ENV_MESSAGE_<your name> environment variable value with your own message.

2. Deploying the changes to the app

   Create the pull request (PR) on your branch. Your changes will get posted automatically to the #govuk-platform-engineering Slack channel for review by a member of the team. After your PR has been approved and passed status checks you can merge your PR.

3. See the changes in Argo CD (a tool to help manage app deployments)

   You should be able to see your changes in the manifest within Argo

4. See your message from the environment variable in the example test app

   Navigate to the test app to see the ENV_MESSAGE as part of the page output, you have now successfully deployed the change to the GOV.UK Kubernetes integration cluster.

5. Tidy up your ENV_MESSAGE

   Revert your PR to tidy up the codebase. After your PR has been approved and passed status checks you can merge your PR to undo your changes.