Use Output of a Bash Command as Parameter Input of a Job Template in Azure DevOps Pipeline

Are you tired of hardcoding values in your Azure DevOps pipeline? Do you want to make your pipeline more dynamic and flexible? Look no further! In this article, we’ll show you how to use the output of a bash command as a parameter input of a job template in Azure DevOps pipeline.

Why Use Output of a Bash Command?

There are many scenarios where you might want to use the output of a bash command as a parameter input. For example:

• You want to retrieve the latest version of a package from a repository and use it in your pipeline.
• You need to get the output of a complex calculation and use it as an input for a subsequent task.
• You want to read a JSON file and use its contents as variables in your pipeline.

By using the output of a bash command, you can make your pipeline more dynamic and responsive to changing conditions.

Prerequisites

Before we dive into the instructions, make sure you have:

• An Azure DevOps organization with a project set up.
• A pipeline created in Azure DevOps with a bash task.
• A basic understanding of bash scripting and Azure DevOps pipelines.

Step 1: Create a Bash Task

Create a new bash task in your Azure DevOps pipeline. You can do this by clicking on the “Tasks” tab in your pipeline and then clicking on the “New Task” button.

In the “New Task” dialog, select “Bash” as the task type and give your task a name, such as “Get Package Version”. Click “Add” to add the task to your pipeline.

tasks:
- task: Bash@3
  displayName: 'Get Package Version'
  inputs:
    command: 'bash'
    workingDirectory: ''
    script: |
      #!/bin/bash
      PACKAGE_VERSION=$(curl -s https://api.example.com/package/version)
      echo "##vso[task.setvariable variable=PACKAGE_VERSION;issecret=false]$PACKAGE_VERSION"

In the above script, we’re using `curl` to retrieve the package version from a fictional API. The `echo` statement sets the `PACKAGE_VERSION` variable, which we’ll use later.

Step 2: Create a Job Template

Create a new job template in your Azure DevOps pipeline. You can do this by clicking on the “Jobs” tab in your pipeline and then clicking on the “New Job” button.

In the “New Job” dialog, give your job a name, such as “Deploy to Staging”. Click “Add” to add the job to your pipeline.

jobs:
- job: Deploy_to_Staging
  steps:
  - task: Bash@3
    displayName: 'Deploy to Staging'
    inputs:
      command: 'bash'
      workingDirectory: ''
      script: |
        #!/bin/bash
        echo "Deploying to staging with package version $(PACKAGE_VERSION)"
        # Deploy to staging logic here

In the above script, we’re using the `PACKAGE_VERSION` variable set in the previous task to deploy to staging.

Step 3: Use Output of Bash Command as Parameter Input

To use the output of the bash command as a parameter input for the job template, we need to modify the job template to accept a parameter.

jobs:
- job: Deploy_to_Staging
  parameters:
    packageVersion: ''
  steps:
  - task: Bash@3
    displayName: 'Deploy to Staging'
    inputs:
      command: 'bash'
      workingDirectory: ''
      script: |
        #!/bin/bash
        echo "Deploying to staging with package version ${packageVersion}"
        # Deploy to staging logic here

In the above script, we’ve added a `parameters` section to the job template, which defines a `packageVersion` parameter.

Step 4: Pass Output of Bash Command as Parameter Input

To pass the output of the bash command as a parameter input to the job template, we need to modify the pipeline to pass the `PACKAGE_VERSION` variable as a parameter.

stages:
- stage: Deploy
  jobs:
  - job: Deploy_to_Staging
    steps:
      - task: Bash@3
        displayName: 'Get Package Version'
        inputs:
          command: 'bash'
          workingDirectory: ''
          script: |
            #!/bin/bash
            PACKAGE_VERSION=$(curl -s https://api.example.com/package/version)
            echo "##vso[task.setvariable variable=PACKAGE_VERSION;issecret=false]$PACKAGE_VERSION"
      - job: Deploy_to_Staging
        parameters:
          packageVersion: $(PACKAGE_VERSION)

In the above script, we’ve added a `parameters` section to the pipeline, which passes the `PACKAGE_VERSION` variable as a parameter to the job template.

Conclusion

In this article, we’ve shown you how to use the output of a bash command as a parameter input of a job template in Azure DevOps pipeline. By following these steps, you can make your pipeline more dynamic and flexible, and reduce the need for hardcoding values.

Remember to adapt the scripts to your specific use case, and don’t hesitate to ask for help if you encounter any issues.

Frequently Asked Questions

Q: Can I use the output of a bash command as a parameter input for a task?

A: Yes, you can use the output of a bash command as a parameter input for a task by setting a variable in the bash script and then using that variable as a parameter input for the task.

Q: How do I pass multiple outputs of a bash command as parameter inputs to a job template?

A: You can pass multiple outputs of a bash command as parameter inputs to a job template by setting multiple variables in the bash script and then using those variables as parameter inputs for the job template.

Q: Can I use the output of a bash command as a condition for a job template?

A: Yes, you can use the output of a bash command as a condition for a job template by setting a variable in the bash script and then using that variable as a condition for the job template.

Parameter	Description
PACKAGE_VERSION	The output of the bash command, which is used as a parameter input for the job template.
packageVersion	The parameter input for the job template, which accepts the output of the bash command.

By following the instructions in this article, you should now be able to use the output of a bash command as a parameter input of a job template in Azure DevOps pipeline. Happy piping!

Frequently Asked Question

Get the inside scoop on using output of a bash command as parameter input of a job template in Azure DevOps pipeline!