====== Jenkins: Multibranch Pipeline ======

**General Information**

A Jenkins Multibranch pipeline job is flexible because it scans your project for all available branches that have a matching Jenkinsfile and adds that pipeline job.

**Checklist**
  * Jenkins master server installed
  * Available Git repo

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====== Creating a multibranch pipeline ======

Creating a multibranch pipeline is similar to creating a standard pipeline job.

  * Click "New Item"
  * Enter an item name: <name of multibranch job>
  * Click "Multibranch Pipeline", then click "Ok"

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===== Initial Configuration =====

After creation, you are brought to the initial multibranch pipeline configuration page.

  * Under "Branch Sources", click "Add source", then click the type of project (such as Git)
    * Project Repository: <paste URL that you can clone the project from>
    * Credentials: Select your saved project credentials (if required)
    * Behaviors: Default is to discover all branches
    * Build strategies: There are a number of build strategies that can influence which branches are built and when.
      * See the next section for some of them.
      * **Note**: The default of no build strategies will execute each pipeline found in each branch upon initial discovery (such as when you click Save) OR after each scan that finds a commit change. If this is NOT the desired behavior, look at the available build strategies.
    * Build Configuration
      * Mode: by Jenkinsfile
      * Script Path: Enter the path to the Jenkinsfile stored in the project. This is the pipeline file that will be scanned for in each branch.
    * Scan Multibranch Pipeline Triggers: Check this box and select how often to scan the project for branches and Jenkinsfiles in those branches.
    * Click "Save" to save the job configuration

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===== Build Strategies =====

Build strategies are ways to limit what branches are built and when.

  * "Suppress automatic SCM triggering"
    * Do not build on changes during a multibranch scan.
    * **Note**: This strategy is removed when you install the plugin "Basic Branch Build Strategies Plugin" below, but can be achieved in a different way.

  * Install the plugin: [[https://wiki.jenkins.io/display/JENKINS/Basic+Branch+Build+Strategies+Plugin|Basic Branch Build Strategies Plugin]]
    * "All Strategies Match"
      * The strategies contained are all used together. This strategy must be used to contain the next two if you don't want automatic scm triggering.
      * "Skip initial build on first branch indexing"
        * Don't build upon initial branch discovery (will build every time after if changes are discovered unless further build strategies are added)
      * "Named Branches"
        * Add "Wildcard include/exclude"
          * "Exclude: *"
            * This will exclude all matched branch names from building - useful if you only want to build branches explicitly and not automatically. (such as deploy jobs) You could also only exclude branches that may deploy to production (For example: master)

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