credits:

• https://github.com/microsoft/variable-substitution

With the Variable Substitution Action for GitHub, you can apply variable substitution to XML, JSON and YAML based configuration and parameter files.

• Tokens defined in the target configuration files are updated and then replaced with variable values.
• Variable substitution is applied for only the JSON keys predefined in the object hierarchy. It does not create new keys.
• Only variables defined explicitly as Environment variables as part of the workflow or system variables that are already available for workflow context can be used in substitution.
• Variable substitution takes effect only on the applicationSettings, appSettings, connectionStrings and configSections elements of configuration files. Please refer this for more information.

If you are looking for more Github Actions to deploy code or a customized image into an Azure Webapp or a Kubernetes service, consider using Azure Actions.

The definition of this Github Action is in action.yml.

See Use variable substitution with GitHub Actions for an example of how to use variable substitution.

# .github/workflows/var-substitution.yml
on: [push]
name: variable substitution in json, xml, and yml files

jobs:
  build:
    runs-on: windows-latest
    steps:
    - uses: actions/checkout@v2

    - uses: microsoft/variable-substitution@v1 
      with:
        files: 'Application/*.json, Application/*.yaml, ./Application/SampleWebApplication/We*.config'
      env:
        Var1: "value1"
        Var2.key1: "value2"
        SECRET: ${{ secrets.SOME_SECRET }}