Pipeline triggers

Azure Pipeline Triggers automate the start of your build and deployment workflows when specific events or conditions occur. By using triggers effectively, you can streamline code validation, testing, and delivery across your CI/CD lifecycle.

Azure Pipelines supports four primary trigger types:

Continuous Integration (CI) Triggers

Continuous Integration (CI) triggers automatically queue a pipeline run whenever new commits are pushed to selected branches. This immediate feedback loop helps catch build failures or integration errors early.

In YAML pipelines, enable CI by defining the trigger section:

trigger:
  branches:
    include:
      - main
      - release/*
      - feature/*

• trigger: activates CI-based runs
• branches.include: lists branch patterns to watch
  • main builds production code
  • release/* handles hotfix or release branches
  • feature/* catches ongoing development work

Scheduled Triggers

Scheduled triggers run pipelines at specified intervals or cron schedules—ideal for nightly builds, periodic tests, or routine deployments.

To disable CI and add a schedule in YAML:

trigger: none              # Turn off CI-based runs
schedules:
  - cron: "0 2 * * 1-5"     # Weekdays at 02:00 UTC
    displayName: Weekday Early-Build
    branches:
      include:
        - main
    always: true           # Run even without new commits

• trigger: none ensures only scheduled runs occur
• cron: follows standard cron syntax (min, hour, dom, mon, dow)
• always: true runs the job regardless of changes

Pull Request (PR) Triggers

PR triggers automatically validate code changes when a pull request is opened or updated. This enforces quality gates before merging to protected branches.

Example YAML configuration:

pr:
  branches:
    include:
      - main
      - develop
      - feature/*
  paths:
    exclude:
      - docs/**

• pr: defines pull request validation triggers
• branches.include: lists target branches for PR checks
• paths.exclude: skips runs when only documentation changes

Manual Triggers

Manual triggers allow teams to start pipelines on demand for production rollouts, hotfix deployments, or ad hoc testing.

You can invoke a manual run via:

• Azure DevOps UI: Click Run pipeline and select parameters
• Azure CLI:

az pipelines run \
  --name MyPipeline \
  --branch feature/hotfix \
  --variables deployEnv=staging

Best Practices

Adopt these recommendations to keep your pipelines efficient and reliable:

• Be selective with branch filters to reduce unnecessary runs.
• Use path and tag filters to scope triggers precisely.
• Combine CI, PR, and scheduled triggers for comprehensive coverage.
• Implement manual approvals for production or compliance-sensitive deployments.
• Regularly review and clean up stale schedules or branch patterns.

References

• Azure Pipelines triggers
• YAML schema for Azure Pipelines
• Cron syntax guide