Parallel job execution in Azure DevOps to increase build efficiency

Question

Pulumi · Accepted Answer

Using Pulumi to configure Azure DevOps to execute parallel jobs for increased build efficiency involves creating a build definition that defines multiple jobs and stages which can run concurrently. Let's create a simple Pulumi program that sets up an Azure DevOps project and a build pipeline with parallel execution.

Before using the following TypeScript program, ensure that you have Pulumi and the necessary Azure DevOps provider installed and configured.

1. **Installation**: Install Pulumi and set up the Azure DevOps extension.
2. **Configuration**: Ensure that your Pulumi stack is configured with appropriate Azure DevOps access tokens and organization information.

Below is a Pulumi program that sets up an Azure DevOps Project and creates a new build definition using the `azuredevops` package. In this config, the `BuildDefinition` resource allows specifying parallel jobs by manipulating the `jobs` element within your pipeline YAML definition. We will use inline comments to guide you through the program:

```typescript
import * as azuredevops from "@pulumi/azuredevops";

// Create an Azure DevOps Project where the build pipeline will be defined
const project = new azuredevops.Project("exampleProject", {
    // Define the name and description for the project
    name: "MyParallelExecutionProject",
    description: "A project to demonstrate parallel job execution in Azure DevOps",
    // Project visibility can be set to 'private' or 'public'
    visibility: "private",
});

// A build definition with a YAML pipeline configuration that includes parallel jobs
const buildDefinition = new azuredevops.BuildDefinition("exampleBuildDef", {
    // Link to the created project
    projectId: project.id,
    name: "ParallelJobPipeline",
    // Define the YAML pipeline configuration
    repository: {
        // A placeholder for the repository ID, which you need to replace with your actual repo ID
        repoId: "<repository_id>",
        ymlPath: "azure-pipelines.yml", // This should be the path to your YAML pipeline file
        repoType: "TfsGit", // Assuming the repo is in Azure DevOps, use 'GitHub' for GitHub repos
    },
    // The YAML configuration below is a minimal example showcasing parallelism
    // In a real-world scenario, replace this with your actual pipeline configuration
    ciTrigger: {
        // Trigger the pipeline on changes to the specified YAML path
        useYaml: true,
    },
    // Associate this build definition with an agent pool
    agentPoolName: "Azure Pipelines",
    variables: [], // Define any necessary pipeline variables here
});

export const projectName = project.name;
export const buildDefinitionName = buildDefinition.name;
```

You'll notice the `azure-pipelines.yml` placeholder, which would be an actual file in your Azure DevOps repo. This file specifies the stages, jobs, and steps of your build, and it's where you'll define parallel jobs. Here's a simple example of what the YAML file could look like to leverage parallel execution:

```yaml
# `azure-pipelines.yml` sample
trigger:
- main

pool:
  vmImage: 'ubuntu-latest'

stages:
- stage: Build
  jobs:
  - job: Backend
    steps:
    - script: echo Building backend...
      displayName: 'Build Backend'

- job: Frontend
    steps:
    - script: echo Building frontend...
      displayName: 'Build Frontend'

- job: Tests
    steps:
    - script: echo Running tests...
      displayName: 'Run Tests'
```

In this configuration, we define a build stage with three jobs: `Backend`, `Frontend`, and `Tests`. Azure DevOps will attempt to run these jobs in parallel, given enough available agents in the pool.

To apply this Pulumi program:
1. Save the TypeScript code in a file named `index.ts`.
2. Save the YAML in a file named `azure-pipelines.yml` in the root of the repository referenced in your Pulumi program.
3. Run `pulumi up` to deploy the changes.
4. Check Azure DevOps for the new project and build definition, and run a build to see parallel execution in action.

The above program and YAML configuration serve as a foundation. For a real-world setup, you will have to expand and adapt the YAML configuration according to the requirements of your build pipeline, such as adding more complex build steps, using specific agents, handling dependencies between jobs, or customizing the build strategy to control the parallelism level.