importer-labs/jenkins/valet-migrate-lab.md

Migrate a Jenkins Project to GitHub Actions

In this lab, we will use the Valet migrate command to migrate a Jenkins pipeline to GitHub Actions. The previous commands used in the labs, such as audit and dry-run have prepared us to run a migration. The migrate command will transform the Jenkins pipeline into a GitHub Actions workflow like the dry-run command did, but instead of writing these files locally, it will open a pull request with the files. The pull request will contain a checklist of Manual Tasks if required. These tasks are changes that Valet could not do on our behalf, like creating a runner or adding a secret to a repository.

• Prerequisites
• Preparing for migration
• Performing the migration
• Reviewing the pull request
• Next Lab

Prerequisites

1. Followed steps to set up your codespace environment.
2. Completed the configure lab
3. Completed the dry-run lab
4. Completed the dry-run lab with custom transformer

Preparing for migration

Before running the command we need to collect some information:

1. What is the name of the pipeline we want to convert? monas_dev_work/job/monas_freestyle
2. What is the source URL of the pipeline we want to convert? http://localhost:8080/monas_dev_work/job/monas_freestyle
3. Where do we want to store the result? ./tmp/migrate.
4. What is the URL for the GitHub repository we want to add the workflow too? this repo!. When constructing the value for the migrate command it should match this url https://github.com/GITHUB-ORG-USERNAME-HERE/GITHUB-REPO-NAME-HERE with GITHUB-ORG-USERNAME and GITHUB-REPO-NAME substitued with your values

Performing a migration

1. Run migrate command using the information collected above, make sure to update the --target-url value with the information from step 4.

gh valet migrate jenkins --target-url https://github.com/GITHUB-ORG-USERNAME-HERE/GITHUB-REPO-NAME-HERE --output-dir ./tmp/migrate --source-url http://localhost:8080/job/monas_dev_work/job/monas_freestyle

2. Valet will create a pull request directly in the target GitHub repository.
3. Open the pull request by clicking the green pull request link in the output of the migrate command, if you have trouble clicking it you can always copy and paste the url in your browser.

Reviewing the pull request

• Lets first look at the Conversation tab of the PR. It tells us we have a manual task to perform before the GitHub Actions workflow is functional. We need to add a secret. We can use the GitHub documentation for secrets and add a actions secret for EXPRESSION_FIRST_VAR with any value.

• Next, lets review the workflow we are adding by clicking on Files changed tab. This is where you would double check everything looks good. If it didn't you could push commits with the required changes, prior to merging.

• Now our review is completed we want to go back to the Conversation tab and click Merge pull request

• Once the PR is merged the new workflow should start and we can view it by clicking Actions in the top navigation

• The migration is complete and we have successfully transformed a pipeline from Jenkins into a GitHub Actions workflow, added it to a GitHub Repository, and run the workflow in Actions.

Next Lab

Forecast Jenkins Usage