# Key CI/CD/Jenkins Concepts and their Usage

## Configuring Build Triggers and Steps for a Job

1. Add a default value for the build parameter named `MESSAGE` e.g. `Hello World!`.
2. Create a build trigger that builds the project every minute.
3. Add a build step that executes the shell command `echo 'Message: $MESSAGE'`. The message is value of the parameter.
4. After a minute the first execution should have been triggered. Check the log output of the build and find the rendered message.
5. Create another freestyle project named `downstream-job` in the same folder.
6. Configure the initial job to execute the `downstream-job` if it was stable.

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Modify the existing build parameter.

![String Parameter](./images/03-build-trigger-and-steps/string-parameter.png)

Add the cron build trigger and the build step.

![Build Trigger And Step](./images/03-build-trigger-and-steps/build-trigger-and-step.png)

The output render the interpolated value of the `echo` command.

```bash
Started by timer
Running as SYSTEM
Building in workspace /Users/bmuschko/.jenkins/workspace/freestyle/my-freestyle-job
[my-freestyle-job] $ /bin/sh -xe /var/folders/02/3dgzjkqj4kz0g7lnrk0w93c00000gn/T/jenkins3548490840940668236.sh
+ echo 'Message: Hello World!'
Message: Hello World!
Finished: SUCCESS
```

Create a new job in the same folder.

![Both Jobs In Folder](./images/03-build-trigger-and-steps/both-jobs-in-folder.png)

Configure the downstream job from the initial job.

![Downstream Job Configuration](./images/03-build-trigger-and-steps/build-downstream.png)

The downstream job indicates the upstream job.

![Downstream Build Information](./images/03-build-trigger-and-steps/executed-downstream-job.png)

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