Configuring CI Using Azure Pipelines and Nx
Below is an example of an Azure Pipelines setup building and testing only what is affected.
1trigger:
2  - main
3pr:
4  - main
5
6variables:
7  CI: 'true'
8  ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
9    NX_BRANCH: $(System.PullRequest.PullRequestId) # You can use $(System.PullRequest.PullRequestNumber if your pipeline is triggered by a PR from GitHub ONLY)
10    TARGET_BRANCH: $[replace(variables['System.PullRequest.TargetBranch'],'refs/heads/','origin/')]
11    BASE_SHA: $(git merge-base $(TARGET_BRANCH) HEAD)
12  ${{ if ne(variables['Build.Reason'], 'PullRequest') }}:
13    NX_BRANCH: $(Build.SourceBranchName)
14    BASE_SHA: $(git rev-parse HEAD~1)
15  HEAD_SHA: $(git rev-parse HEAD)
16
17jobs:
18  - job: main
19    pool:
20      vmImage: 'ubuntu-latest'
21    steps:
22      - checkout: self
23        fetchDepth: 0
24
25      # Set Azure Devops CLI default settings
26      - bash: az devops configure --defaults organization=$(System.TeamFoundationCollectionUri) project=$(System.TeamProject)
27        displayName: 'Set default Azure DevOps organization and project'
28      # Get last successfull commit from Azure Devops CLI
29      - displayName: 'Get last successful commit SHA'
30        condition: ne(variables['Build.Reason'], 'PullRequest')
31        env:
32          AZURE_DEVOPS_EXT_PAT: $(System.AccessToken)
33        bash: |
34          LAST_SHA=$(az pipelines build list --branch $(Build.SourceBranchName) --definition-ids $(System.DefinitionId) --result succeeded --top 1 --query "[0].triggerInfo.\"ci.sourceSha\"")
35          if [ -z "$LAST_SHA" ]
36          then
37            echo "Last successful commit not found. Using fallback 'HEAD~1': $BASE_SHA"
38          else
39            echo "Last successful commit SHA: $LAST_SHA"
40            echo "##vso[task.setvariable variable=BASE_SHA]$LAST_SHA"
41          fi
42
43      # Required for nx affected if we're on a branch
44      - script: git branch --track main origin/main
45      # This line enables distribution
46      # The "--stop-agents-after" is optional, but allows idle agents to shut down once the "e2e-ci" targets have been requested
47      - script: npx nx-cloud start-ci-run --distribute-on="5 linux-medium-js" --stop-agents-after="e2e-ci"
48      - script: npm ci
49
50      - script: npx nx-cloud record -- nx format:check --base=$(BASE_SHA)
51      - script: npx nx affected --base=$(BASE_SHA) -t lint test build e2e-ci
52Get the Commit of the Last Successful Build
In the example above, we ran a script to retrieve the commit of the last successful build. The idea is to use Azure Devops CLI directly in the Pipeline Yaml
First, we configure Devops CLI
1# Set Azure Devops default settings
2- bash: az devops configure --defaults organization=$(System.TeamFoundationCollectionUri) project=$(System.TeamProject)
3  displayName: 'Configure Azure DevOps organization and project'
4Then we can query the pipelines API (providing the auth token)
1# Get last successfully commit infos from Azure Devops
2- bash: |
3    LAST_SHA=$(az pipelines build list --branch $(Build.SourceBranchName) --definition-ids $(System.DefinitionId) --result succeeded --top 1 --query "[0].triggerInfo.\"ci.sourceSha\"")
4    echo "Last successful commit SHA: $LAST_SHA"
5    echo "##vso[task.setvariable variable=BASE_SHA]$LAST_SHA"
6  displayName: 'Get last successful commit SHA'
7  env:
8    AZURE_DEVOPS_EXT_PAT: $(System.AccessToken)
9We can target a specific build; in this example, we specified:
- The branch (--branch)
- The pipeline ID (--definition-ids)
- The result type (--result)
- The number of the result (-top)
The command returns an entire JSON object with all the information. But we can narrow it down to the desired result with the --query param that uses JMESPath format (more details)
Finally, we extract the result in a common custom variable named BASE_SHA used later by the nx format and nx affected commands.