GitHub Actions Workflow Part 3 – Jobs
Hello Everyone
Welcome to CloudAffaire and this is Debjeet.
In today’s blog post, we will discuss jobs workflow element in GitHub. A job is an intent of single or multiple actions that you want to perform in your GitHub workflow. A job comprises of mainly a job name and id to uniquely identify each job in the GitHub workflow, target (runs_on) where the job will get executed and actions (steps) that the job needs to carry out.
Jobs id (required) and name (optional): Each job must have an id in the form of a string that uniquely identify the job in the workflow. You can also assign a name to your job that gets displayed in GitHub.
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name: GitHub Actions Demo on: [push] jobs: my_first_job: # jobs id, must be unique name: job1 # jobs name |
Jobs needs (optional): You can create dependency of one job to another using needs workflow element. If the job defined in needs failed then the parent job doesn’t get executed. You can override this with always() that ensures even if the dependent job is failed the parent job always gets executed.
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name: GitHub Actions Demo on: [push] jobs: job1: needs: [job2, job3] # job1 start execution once job2 and job3 succeeds job2: needs: job3 # job2 start execution once job3 succeeds job3: # order of execution: job3 => job2 & job4 => job1 job4: always() # even if job3 failed, job4 will get executed needs: job3 |
Jobs runs-on (required): You can define the target system known as GitHub runner where the job will get executed using runs-on workflow element. You can use a self-hosted (dedicated) or GitHub-hosted (shared) runner to execute your jobs. Below is the list of GitHub-hosted runner that you can use currently.
- windows-2022: Windows Server 2022[beta]
- windows-latest or windows-2019: Windows Server 2019
- windows-2016: Windows Server 2016
- ubuntu-latest or ubuntu-20.04: Ubuntu 20.04
- ubuntu-18.04: Ubuntu 18.04
- macos-11: macOS Big Sur 11
- macos-latest or macos-10.15: macOS Catalina 10.15
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name: GitHub Actions Demo on: [push] jobs: my_first_job: name: job1 runs-on: ubuntu-latest # the job will use GitHub-hosted ubuntu runner |
If you are using a self-hosted runner, you need to provide the self-hosted label along with other custom labels as an array to runs-on workflow element.
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name: GitHub Actions Demo on: [push] jobs: my_first_job: name: job1 runs-on: [self-hosted, linux] # the job will use self-hosted linux runner |
Jobs outputs (optional): A map of outputs for a job. Job outputs are available to all downstream jobs that depend on this job. Job outputs are strings, and job outputs containing expressions are evaluated on the runner at the end of each job. Outputs containing secrets are redacted on the runner and not sent to GitHub Actions.
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name: GitHub Actions Demo on: [push] jobs: job1: runs-on: ubuntu-latest # Map a step output to a job output outputs: output1: ${{ steps.step1.outputs.test }} output2: ${{ steps.step2.outputs.test }} steps: - id: step1 run: echo "::set-output name=test::hello" - id: step2 run: echo "::set-output name=test::world" job2: runs-on: ubuntu-latest needs: job1 steps: - run: echo ${{needs.job1.outputs.output1}} ${{needs.job1.outputs.output2}} |
Jobs if (optional): You can use if condition inside a job to execute the job based on some condition evaluation.
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name: GitHub Actions Demo on: [push] jobs: job1: name: job1 runs-on: ubuntu-latest if: ${{ true }} steps: - name: step1 run: echo "executed as true" job2: name: job2 runs-on: ubuntu-latest if: ${{ false }} steps: - name: step2 run: echo "not executed as false" |
Jobs timeout-minutes (optional): The maximum number of minutes to let a job run before GitHub automatically cancels it, default: 360. If the timeout exceeds the job execution time limit for the runner, the job will be canceled when the execution time limit is met instead.
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name: GitHub Actions Demo on: [push] jobs: job1: name: job1 runs-on: ubuntu-latest timeout-minutes: 1 steps: - name: step1 run: sleep 70 |
Jobs continue-on-error (optional): Prevents a workflow run from failing when a job fails. Set to true to allow a workflow run to pass when this job fails.
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name: GitHub Actions Demo on: [push] jobs: job1: name: job1 runs-on: ubuntu-latest continue-on-error: true steps: - name: step1 run: simulate error job2: name: job2 runs-on: ubuntu-latest steps: - name: step1 run: echo "I still get executed" |
Jobs strategy (optional): You can use strategy to create a build matrix to run different variations of a job from a single definition.
- Jobs strategy matrix (optional): You can define a matrix of different job configurations. A matrix allows you to create multiple jobs by performing variable substitution in a single job definition.
- Jobs strategy fail-fast (optional): When set to true, GitHub cancels all in-progress jobs if any matrix job fails. Default: true
- Jobs strategy max-parallel (optional): The maximum number of jobs that can run simultaneously when using a matrix job strategy.
Jobs uses (optional): The location and version of a reusable workflow file to run as a job. {owner}/{repo}/{path}/{filename}@{ref} where {ref} can be a SHA, a release tag, or a branch name.
Jobs with (optional): When a job is used to call a reusable workflow, you can use with to provide a map of inputs that are passed to the called workflow. Any inputs that you pass must match the input specifications defined in the called workflow.
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name: GitHub Actions Demo on: [push] jobs: job1: name: job1 runs-on: ubuntu-latest strategy: matrix: node: [10, 12, 14] fail-fast: false max-parallel: 2 steps: - uses: actions/setup-node@v2 with: node-version: ${{ matrix.node }} |
Jobs secrets (optional): If you have stored any secret like passwords or api keys in your repository and want to access and use the secret in your workflow, use secrets element of GitHub workflow.
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name: GitHub Actions Demo on: [push] jobs: job1: name: job1 runs-on: ubuntu-latest steps: - shell: bash env: API_KEY: ${{ secrets.access_key }} run: | echo "My secret api key is $API_KEY" |
Hope you have enjoyed this article. To know more about GitHub, please refer below official documentation