1. Branch-based Model Versioning for Continuous Integration


    Branch-based model versioning is a strategy for managing software development where each feature or bug fix is developed in its own branch. Continuous Integration (CI) can be applied to this model by automating the testing and building of software whenever there is a commit to any branch in a repository. In the context of Pulumi, which is an Infrastructure as Code tool, CI practices can be employed to automate the provisioning and management of infrastructure.

    To achieve continuous integration with branch-based model versioning using Pulumi, you would generally take the following steps:

    1. Initialize a Repository: Set up your version control system (e.g., GitHub, GitLab, Bitbucket) with a repository that contains your Pulumi code.

    2. Set up CI/CD Pipeline: Configure CI/CD pipelines in your CI tool (e.g., GitHub Actions, GitLab CI/CD, Jenkins) to run when changes are pushed to any branch.

    3. Write Pulumi Code: Write your infrastructure code using Pulumi's SDK, such as pulumi_aws for AWS resources.

    4. Run Pulumi Preview/Test: Add a step in your CI pipeline to run pulumi preview or pulumi up --yes in 'test' mode to show what changes would be made without actually making them.

    5. Merge Requests: Use Pull/Merge Requests to review the Pulumi plan and the code. Once approved and tests pass, it can be merged to the main branch.

    6. Deploy Changes: A merge to the main branch can trigger a Pulumi update that applies your changes to your cloud provider.

    Below is a simple Pulumi Python program example in which a CI process might be triggered by a commit to any branch on a gitlab repository. Note that this example assumes that you already have the GitLab and Pulumi CLI configured with necessary credentials and that the CI pipeline is already set up in GitLab to trigger on branch commits.

    import pulumi import pulumi_gitlab as gitlab # This represents the creation of a GitLab project which should ideally # be the source of your Pulumi templates. project = gitlab.Project("example-project", # A description is useful to understand the purpose of the project. description="An example project to demonstrate branch-based model versioning for CI", # Visibility level is important to determine who can access the project. visibility_level="public") # Adding a pipeline trigger which can be called by CI system to trigger GitLab CI/CD pipelines. trigger = gitlab.PipelineTrigger("example-trigger", project=project.id, # The description helps to understand the purpose of this pipeline trigger. description="Trigger for branch-based CI/CD pipelines") # A branch in the GitLab project for feature development. feature_branch = gitlab.Branch("example-feature-branch", project=project.id, # Branch name which should follow your naming conventions for features. name="feature/awesome-feature", # Ref from which this branch is created, typically the default branch. ref="main") # Export the necessary attributes to be used in CI/CD pipelines or Pulumi stacks management. pulumi.export("project_id", project.id) pulumi.export("pipeline_trigger_token", trigger.token) pulumi.export("feature_branch_name", feature_branch.name)

    In this program, we have:

    • Defined a GitLab project where our Pulumi templates and code will reside.
    • Added a pipeline trigger which is used in the CI system to automate the GitLab CI/CD processes.
    • Created a feature branch for development work which would trigger the CI pipeline when there are new commits.

    This Pulumi program doesn't handle the CI pipeline itself. Handling the CI should be done in the GitLab CI/CD configuration files, which are not managed by Pulumi. However, Pulumi can be used within those CI/CD pipelines to roll out infrastructure changes.

    Remember that each CI system has its specific way of configuration, and the integration between Pulumi and your CI system must be done manually to handle branch triggers, testing, and deployments.