--- stage: Verify group: Runner info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://handbook.gitlab.com/handbook/product/ux/technical-writing/#assignments title: 'Tutorial: Set up CI/CD steps' --- This tutorial shows you how to create and use steps in your pipelines. Steps are reusable and composable pieces of a job. Each step defines structured inputs and outputs that can be consumed by other steps. You can configure steps in local files, GitLab.com repositories, or any other Git source. In this tutorial, use the GitLab CLI (`glab`) to: 1. Create a step that outputs "hello world". 1. Configure a pipeline to use the step. 1. Add multiple steps to a job. 1. Use a remote step to echo all the outputs. ## Before you begin - You must install and sign in to the [GitLab CLI](../../editor_extensions/gitlab_cli/_index.md) (`glab`). ## Create a step First, create a step with: - An `exec` type. - A `command` that's started by the executive API of the system. 1. Create a GitLab project named `zero-to-steps` in your namespace: ```shell glab project create zero-to-steps ``` 1. Go to the root of the project repository: ```shell cd zero-to-steps ``` 1. Create a `step.yml` file. ```shell touch step.yml ``` 1. Use a text editor to add a specification to the `step.yml`: ```yaml spec: inputs: who: type: string default: world ``` - `spec` has one input called `who`. - The input `who` is optional because there is a default value. 1. To add an implementation to the `step.yml`, add a second YAML document after `spec`, with the `exec` key: ```yaml spec: inputs: who: type: string default: world --- exec: command: - bash - -c - echo 'hello ${{inputs.who}}' ``` The triple em dash (`---`) separates the file into two YAML documents: - The first document is the specification, like a function signature. - The second document is the implementation, like a function body. The `bash` and `-c` arguments start a Bash shell and take the script input from the command line arguments. In addition to shell scripts, you can use `command` to execute programs like `docker` or `terraform`. The `echo 'hello ${{input.name}}'` argument includes an expression inside `${{` and `}}`. Expressions are evaluated at the last possible moment and have access to the current execution context. This expression accesses `inputs` and reads the value of `who`: - If `who` is provided by the caller, that value is substituted for the expression. - If `who` is omitted, then the default `world` is substituted for the expression instead. ## Configure a pipeline to use the step 1. In the root of the repository, create a `.gitlab-ci.yml` file: ```shell touch .gitlab-ci.yml ``` 1. In the `.gitlab-ci.yml`, add the following job: ```yaml hello-world: run: - name: hello_world step: . ``` - The `run` keyword has a list of step invocations. - Each invocation is given a `name` so you can reference the outputs in later steps. - Each invocation specifies a `step` to run. A local reference (`.`) points to the root of the repository. For an example of how this code should look in your repository, see the [Steps tutorial, part 1](https://gitlab.com/gitlab-org/step-runner/-/tree/main/examples/tutorial_part_1). 1. Commit both files and push the project repository. This triggers a pipeline that runs the job: ```shell git add . git commit -m 'Part 1 complete' git push --set-upstream origin main glab ci status ``` 1. Follow the job under "View Logs" until the pipeline completes. Here's an example of a successful job: ```shell Step Runner version: a7c7c8fd See https://gitlab.com/gitlab-org/step-runner/-/blob/main/CHANGELOG.md for changes. ... hello world Cleaning up project directory and file based variables Job succeeded ``` You've now created and used your first step! ## Add multiple steps to a job You can have more than one step in a job. 1. In the `.gitlab-ci.yml` file, add another step called `hello_steps` to your job: ```yaml hello-world: run: - name: hello_world step: . - name: hello_steps step: . inputs: who: gitlab steps ``` This `hello_steps` step provides a non-default input `who` of `gitlab steps`. For an example of how this code should look in your repository, see the [Steps tutorial, part 2a](https://gitlab.com/gitlab-org/step-runner/-/tree/main/examples/tutorial_part_2a). 1. Commit and push the changes: ```shell git commit -a -m 'Added another step' git push glab ci status ``` 1. In the terminal, select **View Logs** and follow the pipeline until it completes. Here's an example of a successful output: ```shell Step Runner version: a7c7c8fd See https://gitlab.com/gitlab-org/step-runner/-/blob/main/CHANGELOG.md for changes. ... hello world hello gitlab steps Cleaning up project directory and file based variables Job succeeded ``` ## Refactor your step To refactor your steps, move them from the `.gitlab-ci.yml` to a dedicated file: 1. Move the first step you created to a directory called `hello`: ```shell mkdir hello mv step.yml hello/ ``` 1. Create a new step at the root of the repository. ```shell touch step.yml ``` 1. Add the following configuration to the new `step.yml`: ```yaml spec: --- run: - name: hello_world step: ./hello - name: hello_steps step: ./hello inputs: who: gitlab steps ``` This new step has no inputs, so the `spec` is empty. It is a `steps` type, which has the same syntax as steps in `.gitlab-ci.yml`. However, the local reference now points to your step in the `hello` directory. 1. To use the new step, modify `.gitlab-ci.yml`: ```yaml hello-world: run: - name: hello_everybody step: . ``` Now your job invokes only the new step with no inputs. You've refactored the details of the job into a separate file. For an example of how this code should look in your repository, see the [Steps tutorial, part 2b](https://gitlab.com/gitlab-org/step-runner/-/tree/main/examples/tutorial_part_2b). 1. Commit and push the changes: ```shell git add . git commit -m 'Refactored step config' git push glab ci status ``` 1. In the terminal, select **View Logs**. 1. To verify that the refactored step performs the same function as the step you first created, view the log output. The log output should match the output of the step you created previously. Here's an example: ```shell $ /step-runner ci hello world hello gitlab steps Cleaning up project directory and file based variables Job succeeded ``` ### Add an output to the step Add an output to your `hello` step. 1. In `hello/step.yml`, add an `outputs` structure to the `spec`: ```yaml spec: inputs: who: type: string default: world outputs: greeting: type: string --- exec: command: - bash - -c - echo '{"name":"greeting","value":"hello ${{inputs.who}}"}' | tee ${{output_file}} ``` - In this `spec`, you've defined a single output `greeting` without a default. Because there is no default, the output `greeting` is required. - Outputs are written to the `${{output_file}}` file provided at run time in JSON Line format. Each line written to the output file must be a JSON object with two keys, `name` and `value`. - This step runs `echo '{"name":"greeting","value":"hello ${{inputs.who}}"}'` and sends the output to the job log and the output file (`tee ${{output_file}}`). 1. In `step.yml`, add an output to the step: ```yaml spec: outputs: all_greetings: type: string --- run: - name: hello_world step: ./hello - name: hello_steps step: ./hello inputs: who: gitlab steps outputs: all_greetings: "${{steps.hello_world.outputs.greeting}} and ${{steps.hello_steps.outputs.greeting}}" ``` You've now added an output to this step called `all_greetings`. This output shows the expression syntax: `${{steps.hello_world.outputs.greeting}}`. `all_greetings` reads the outputs of the two sub-steps, `hello_world` and `hello_steps`. Both sub-step outputs are concatenated into a single string output. ## Use a remote step Before you commit and run your code, add another step to your job to see the final `all_greetings` output of your main `step.yml`. This step invocation references a remote step named `echo-step`. The echo step takes a single input `echo`, prints it to the logs, and outputs it as `echo`. 1. Edit the `.gitlab-ci.yml`: ```yaml hello-world: run: - name: hello_everybody step: . - name: all_my_greetings step: gitlab.com/gitlab-org/ci-cd/runner-tools/echo-step@main inputs: echo: "all my greetings say ${{steps.hello_everybody.outputs.all_greetings}}" ``` For an example of how this code should look in your repository, see the [Steps tutorial, part 2c](https://gitlab.com/gitlab-org/step-runner/-/tree/main/examples/tutorial_part_2c). 1. Commit and push the changes: ```shell git commit -a -m 'Added outputs' git push glab ci status ``` 1. Follow the job under "View Logs" until the pipeline completes. Here's an example of a successful output: ```shell Step Runner version: a7c7c8fd See https://gitlab.com/gitlab-org/step-runner/-/blob/main/CHANGELOG.md for changes. ... {"name":"greeting","value":"hello world"} {"name":"greeting","value":"hello gitlab steps"} all my greetings say hello world and hello gitlab steps Cleaning up project directory and file based variables Job succeeded ``` That's it! You've just created and implemented steps in your pipeline. For more information about the syntax for steps, see [CI/CD Steps](../../ci/steps/_index.md).