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Run all pipeline steps in one pod

Harness uses delegates for all operations. To select specific delegates pods to perform the task, Harness uses those delegate pods only. If you don't select specific delegates, Harness manager picks the delegate. For more information, go to How Harness Manager picks delegates.

This topic describes how to run all pipeline steps in a single delegate pod.

Configure pipelines to run steps in the same pod​

When you have multiple steps in your pipeline, you can configure your delegate to run all the steps in the same pod.

To run all the steps in the same pod, do the following:

  1. Create the first step that will select one delegate from the list of eligible delegates, and store it in an output variable.

  2. Provide the output variable in step 1 as a dynamic delegate selector in the consecutive steps/stages to pick one individual delegate among the delegate group.

    For example, in the below pipeline, the select_delegate step stores the delegate hostname as an output variable named HOST_SELECTOR and then provides that as a delegate selector in the use_delegate step.

Example pipeline​

pipeline:
name: test
identifier: test
projectIdentifier: harness-test
orgIdentifier: default
tags: {}
stages:
 - stage:
     name: shell
     identifier: shell
     description: ""
     type: Custom
     spec:
       execution:
         steps:
           - step:
               type: ShellScript
               name: select_delegate
               identifier: select_delegate
               spec:
                 shell: Bash
                 onDelegate: true
                 source:
                   type: Inline
                   spec:
                     script: |
                       echo $HOSTNAME
                       HOST_SELECTOR=$HOSTNAME
                 environmentVariables: []
                 outputVariables:
                   - name: HOST_SELECTOR
                     type: String
                     value: HOST_SELECTOR
               timeout: 10m
           - step:
               type: ShellScript
               name: use delegate
               identifier: use_delegate
               spec:
                 shell: Bash
                 onDelegate: true
                 source:
                   type: Inline
                   spec:
                     script: echo <+execution.steps.select_delegate.output.outputVariables.HOST_SELECTOR>
                 environmentVariables: []
                 outputVariables: []
                 delegateSelectors:
                   - <+execution.steps.select_delegate.output.outputVariables.HOST_SELECTOR>
               timeout: 10m
               failureStrategies: []
     tags: {}