In cases where you need more control over how your apps build and deploy when creating new preview environments, it is possible to leverage the Porter CLI in combination with custom CI actions to handle a wider range of workflows.

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Using the CLI

Spinning up an isolated preview environment is as simple as running the following command: 
porter apply -f porter.yaml --preview
This will create a new preview environment using the currently checked out branch.

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Customizing Github Actions

Porter uses Github Actions to build and deploy your apps. When setting up preview environments, a workflow file with a name like porter-preview-<app-name>.yml will be created in your repository. You can customize this file to suit your needs. For example, it is possible to add conditionals to only run the workflow for specific branches or tags. This can be useful if you want to only create preview environments when a specific branch naming convention is used. If you only want to create preview environments for branches that start with feat/, you can add the following to your workflow file: 
...
jobs:
  porter-deploy:
    runs-on: ubuntu-latest
    if: ${{ startsWith(github.head_ref, 'feat/') }}
    steps:
    - name: Checkout code
...
For more information on Github Actions, see the Github Actions documentation.