remove azure pipeline task from the actions repo

The Azure Pipeline task currently resides in the GitHub
Actions repository, but this structure does not follow
GitHub's guidelines for publishing actions. As a result,
the autogenerated action documentation provides incorrect
usage instructions (e.g., suggesting uses: nginxinc/nginx-for-azure-deploy-action@v0.4.0),
which fails because the action is located in a subdirectory.

Author: kuthiala

.github/workflows/azure-pipeline-build.yml

@@ -1,32 +1,200 @@
-# NGINXaaS for Azure Configuration Automation
+# NGINXaaS for Azure Deployment Action
 
-This repository hosts two essential projects that facilitate the management and deployment of NGINXaaS for Azure configurations. Both projects aim to automate the process of synchronizing NGINX configuration files, but they target different platforms and have unique features and notation. To learn more about NGINXaaS for Azure, please review the [product homepage](https://www.nginx.com/products/nginx/nginxaas-for-azure/).
+This action supports managing the configuration of an [NGINXaaS for Azure](https://docs.nginx.com/nginxaas/azure/quickstart/overview/) deployment in a GitHub repository. It enables continuous deployment through GitHub workflows to automatically update the NGINXaaS for Azure deployment when changes are made to the NGINX configuration files stored in the repository. Additionally, one can update NGINX certificates that are already present in Azure key vault.
 
-## Projects
+## Connecting to Azure
 
-### 1. Azure Pipeline Task
+This action leverages the [Azure Login](https://github.com/marketplace/actions/azure-login) action for authenticating with Azure and performing update to an NGINXaaS for Azure deployment. Two different ways of authentication are supported:
+- [Service principal with secrets](https://docs.microsoft.com/en-us/azure/developer/github/connect-from-azure?tabs=azure-portal%2Cwindows#use-the-azure-login-action-with-a-service-principal-secret)
+- [OpenID Connect](https://docs.microsoft.com/en-us/azure/developer/github/connect-from-azure?tabs=azure-portal%2Cwindows#use-the-azure-login-action-with-openid-connect) (OIDC) with an Azure service principal using a Federated Identity Credential
 
-This project provides a custom Azure pipeline task that automates the synchronization of NGINXaaS configuration files for Azure deployments. It supports both GitHub Action pipelines and Azure DevOps pipeline tasks. [Read more](./azure-pipeline/README.md).
+### Sample workflow that authenticates with Azure using an Azure service principal with a secret
 
-### 2. GitHub Action Task
+```yaml
+# File: .github/workflows/nginxForAzureDeploy.yml
 
-This GitHub Action enables continuous deployment through GitHub workflows to automatically update the NGINXaaS for Azure deployment when changes are made to the NGINX configuration files stored in the repository. It also supports updating NGINX certificates that are present in Azure key vault. [Read more](./github-action/README.md).
+name: Sync the NGINX configuration from the GitHub repository to an NGINXaaS for Azure deployment
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - config/**
 
-## Comparison 
+jobs:
+  Deploy-NGINX-Configuration:
+    runs-on: ubuntu-latest
+    steps:
+    - name: 'Checkout repository'
+      uses: actions/checkout@v2
 
-| Feature/Aspect                      | Azure Pipeline Task                | GitHub Action Task                  |
-|------------------------------------|------------------------------------|-------------------------------------|
-| **CI/CD Automation**               | Yes                                | Yes                                 |
-| **Configuration File Host**        | GitHub Repos or Azure Repos        | GitHub                              |
-| **Security**                       | Pipelines in secured agents        | Azure Login Action                  |
-| **Authentication Methods**         | Service Connection                 | Service Principal with Secrets, OIDC|
-| **Certificate Handling**           | No                                 | Yes (Azure key vault)               |
-| **CI/CD Platform**                 | Azure DevOps                       | GitHub                              |
+    - name: 'Run Azure Login using an Azure service principal with a secret'
+      uses: azure/login@v2
+      with:
+        creds: ${{ secrets.AZURE_CREDENTIALS }}
 
-## Getting Started
+    - name: 'Sync the NGINX configuration from the GitHub repository to the NGINXaaS for Azure deployment'
+      uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+      with:
+        subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+        resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+        nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+        nginx-config-directory-path: config/
+        nginx-root-config-file: nginx.conf
+        transformed-nginx-config-directory-path: /etc/nginx/
+        debug: false
+```
 
-To get started with either of these projects, please refer to the detailed README files linked above. 
+### Sample workflow that authenticates with Azure using OIDC
 
-## License
+```yaml
+# File: .github/workflows/nginxForAzureDeploy.yml
 
-These projects are licensed under the Apache-2.0 License - see the [LICENSE.md](LICENSE) file for details.
+name: Sync the NGINX configuration from the GitHub repository to an NGINXaaS for Azure deployment
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - config/**
+
+permissions:
+      id-token: write
+      contents: read
+
+jobs:
+  Deploy-NGINX-Configuration:
+    runs-on: ubuntu-latest
+    steps:
+    - name: 'Checkout repository'
+      uses: actions/checkout@v2
+
+    - name: 'Run Azure Login using OIDC'
+      uses: azure/login@v2
+      with:
+        client-id: ${{ secrets.AZURE_CLIENT_ID }}
+        tenant-id: ${{ secrets.AZURE_TENANT_ID }}
+        subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+
+    - name: 'Sync the NGINX configuration from the GitHub repository to the NGINXaaS for Azure deployment'
+      uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+      with:
+        subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+        resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+        nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+        nginx-config-directory-path: config/
+        nginx-root-config-file: nginx.conf
+        transformed-nginx-config-directory-path: /etc/nginx/
+        debug: false
+```
+
+> **Note:**
+The service principal being used for authenticating with Azure should have access to manage the NGINXaaS deployment. For simplicity, this guide assumes that the service principal has `Contributor` role to manage the deployment. Refer [prerequisites](https://docs.nginx.com/nginxaas/azure/getting-started/prerequisites/) for details.
+
+## Handling NGINX configuration file paths
+
+To facilitate the migration of the existing NGINX configuration, NGINXaaS for Azure supports multiple-files configuration with each file uniquely identified by a file path, just like how NGINX configuration files are created and used in a self-hosting machine. An NGINX configuration file can include another file using the [include directive](https://docs.nginx.com/nginx/admin-guide/basic-functionality/managing-configuration-files/). The file path used in an `include` directive can either be an absolute path or a relative path to the [prefix path](https://www.nginx.com/resources/wiki/start/topics/tutorials/installoptions/).
+
+The following example shows two NGINX configuration files inside the `/etc/nginx` directory on disk are copied and stored in a GitHub repository under its `config` directory.
+
+| File path on disk                    | File path in the repository      |
+| ------------------------------------ | --------------------------------- |
+| /etc/nginx/nginx.conf                | /config/nginx.conf                |
+| /etc/nginx/sites-enabled/mysite.conf | /config/sites-enabled/mysite.conf |
+
+To use this action to sync the configuration files from this example, the directory path relative to the GitHub repository root `config/` is set to the action's input `nginx-config-directory-path` for the action to find and package the configuration files. The root file `nginx.conf` is set to the input `nginx-root-config-file`.
+
+```yaml
+    - name: 'Sync the NGINX configuration from the GitHub repository to the NGINXaaS for Azure deployment'
+      uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+      with:
+        subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+        resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+        nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+        nginx-config-directory-path: config/
+        nginx-root-config-file: nginx.conf
+        debug: false
+```
+
+By default, the action uses a file's relative path to `nginx-config-directory-path` in the repository as the file path in the NGINXaaS for Azure deployment.
+
+| File path on disk                    | File path in the repository      | File path in the NGINXaaS for Azure deployment |
+| ------------------------------------ | --------------------------------- | ---------------------------------------------- |
+| /etc/nginx/nginx.conf                | /config/nginx.conf                | nginx.conf                                     |
+| /etc/nginx/sites-enabled/mysite.conf | /config/sites-enabled/mysite.conf | sites-enabled/mysite.conf                      |
+
+The default file path handling works for the case of using relative paths in `include` directives, for example, if the root `nginx.conf` references `mysite.conf` using:
+
+```
+include sites-enabled/mysite.conf;
+```
+
+For the case of using absolute paths in `include` directives, for example, if the root `nginx.conf` references `mysite.conf` using:
+
+```
+include /etc/nginx/sites-enabled/mysite.conf;
+```
+
+The action supports an optional input `transformed-nginx-config-directory-path` to transform the absolute path of the configuration directory in the NGINXaaS for Azure deployment. The absolute configuration directory path on disk `/etc/nginx/` can be set to `transformed-nginx-config-directory-path` as follows to ensure the configuration files using absolute paths in `include` directives work as expected in the NGINXaaS for Azure deployment.
+
+```yaml
+    - name: 'Sync the NGINX configuration from the Git repository to the NGINXaaS for Azure deployment'
+      uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+      with:
+        subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+        resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+        nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+        nginx-config-directory-path: config/
+        nginx-root-config-file: nginx.conf
+        transformed-nginx-config-directory-path: /etc/nginx/
+        debug: false
+```
+The transformed paths of the two configuration files in the NGINXaaS for Azure deployment are summarized in the following table
+
+| File path on disk                    | File path in the repository      | File path in the NGINXaaS for Azure deployment |
+| ------------------------------------ | --------------------------------- | ---------------------------------------------- |
+| /etc/nginx/nginx.conf                | /config/nginx.conf                | /etc/nginx/nginx.conf                          |
+| /etc/nginx/sites-enabled/mysite.conf | /config/sites-enabled/mysite.conf | /etc/nginx/sites-enabled/mysite.conf           |
+
+## Handling NGINX certificates
+
+Since certificates are secrets, it is assumed they are stored in Azure key vault. One can provide multiple certificate entries to the github action as an array of JSON objects with keys:
+
+`certificateName`- A unique name for the certificate entry
+
+`keyvaultSecret`- The secret ID for the certificate on Azure key vault
+
+`certificateVirtualPath`- This path must match one or more ssl_certificate directive file arguments in your Nginx configuration; and must be unique between certificates within the same deployment
+
+`keyVirtualPath`- This path must match one or more ssl_certificate_key directive file arguments in your Nginx configuration; and must be unique between certificates within the same deployment
+
+See the example below
+
+```yaml
+- name: "Sync NGINX certificates to NGINXaaS for Azure"
+        uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+        with:
+          subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+          resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+          nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+          nginx-deployment-location: ${{ secrets.NGINX_DEPLOYMENT_LOCATION }}
+          nginx-certificates: '[{"certificateName": "$NGINX_CERT_NAME", "keyvaultSecret": "https://$NGINX_VAULT_NAME.vault.azure.net/secrets/$NGINX_CERT_NAME", "certificateVirtualPath": "/etc/nginx/ssl/my-cert.crt", "keyVirtualPath": "/etc/nginx/ssl/my-cert.key"  } ]'
+          debug: false
+```
+
+## Handling NGINX configuration and certificates
+
+```yaml
+ - name: "Sync NGINX configuration- multi file and certificate to NGINXaaS for Azure"
+        uses: nginxinc/nginx-for-azure-deploy-action/github-action@v0.4.0
+        with:
+          subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
+          resource-group-name: ${{ secrets.AZURE_RESOURCE_GROUP_NAME }}
+          nginx-deployment-name: ${{ secrets.NGINX_DEPLOYMENT_NAME }}
+          nginx-deployment-location: ${{ secrets.NGINX_DEPLOYMENT_LOCATION }}
+          nginx-config-directory-path: config/
+          nginx-root-config-file: nginx.conf
+          transformed-nginx-config-directory-path: /etc/nginx/
+          nginx-certificates: '[{"certificateName": "$NGINX_CERT_NAME", "keyvaultSecret": "https://$NGINX_VAULT_NAME.vault.azure.net/secrets/$NGINX_CERT_NAME", "certificateVirtualPath": "/etc/nginx/ssl/my-cert.crt", "keyVirtualPath": "/etc/nginx/ssl/my-cert.key"  } ]'
+          debug: false
+```