App Service Networking Samples

This project contains a sample setup for playing with Azure App Service networking features.

Features

This project provides the following features:

Base setup for a web application and database.
VNet with several subnets.
Application gateway installed in the application gateway subnet and with a public IP address associated to it, and a backend pool for the web app.
Azure Front Door service with a backend pool for the web app.
Walkthroughs of several networking setups and explanation for Azure App Service.

The below drawing illustrates this setup:

Getting Started

Prerequisites

An Azure Account.
(Optional) A fork of this GitHub repository in your own account and with the capability of executing GitHub actions (public repository access is needed for this).
The latest Azure CLI version installed. Azure Cloud Shell can also be used as an alternative for the script steps in case Azure CLI is not installed.

Installation

Option 1: Using GitHub Actions

The below walkthrough contains the steps for creating a resource group in Azure and the steps needed to set up your deployment secret in your GitHub repository.

In a command prompt or in Azure Cloud Shell, define environment variables.
```
RESOURCE_GROUP='appsvcnetworkingdemo'
LOCATION=westus
```
Login to your Azure account and make sure the correct subscription is active.
```
az login
az account list -o table
az account set <your-subscription-id>
```

Create a resource group for all necessary resources.

az group create --name $RESOURCE_GROUP --location $LOCATION

Copy the resource group ID which is outputted in the previous step to a new environment variable.
```
RESOURCE_GROUP_ID=<resource group ID from previous output>
```

Create a service principal and give it access to the resource group.

az ad sp create-for-rbac \
  --name appsvcnetworkingdemo \
  --role Contributor \
  --scopes $RESOURCE_GROUP_ID \
  --sdk-auth

Copy the full output from this command.
In your GitHub repo navigate to Settings > Secrets and select New Repository Secret.
Name the secret AZURE_CREDENTIALS and paste the output from the 'az ad sp create-for-rbac' command in the value textbox.
Select Add Secret.

In your command prompt, query the object id for your user account:

az ad user show --id <accountname@domain.extension> --query id -o tsv

In your GitHub repo add an additional secret: AAD_USERNAME and give it the value of your username accountname@domain.extension.
In your GitHub repo add an additional secret: AAD_SID and give it the value of the object id you just obtained.
Inspect the infradeploy.yml file and update any environment variables at the top of the file to reflect your environment.
In your GitHub repo, navigate to Actions and select the deploy-app-svc-networking-sample action.

NOTE: In case you see a message that says Workflows aren't being run on this forked repository, select the I understand my workflows, go ahead and enable them button.
Select Run workflow > Run workflow.
This will start a new workflow run and deploy the necessary infrastructure.
Double check in the Azure Portal that all resources got deployed correctly and are up and running.
In the Azure Portal in your resource group, navigate to the Deployments menu. Select the last deployment and next select outputs.
Copy the value of the principalId value.
In the Azure Portal, navigate to the sample SQL database and open Query Editor.
Select Login as your username.
Copy the sql script from mi.sql in the query editor window and replace each instance of the accountName by the principalId value you just copied.
Execute the script.

To check whether the installation was done correctly:

In the Azure portal, navigate to the App Service that got deployed.
Select the URL of the App Service to navigate to the web application. The application will display info on your incoming request, configuration of the app, environment variables, ...
Select the SQL menu tab at the top of the application. This will display a page for connecting to a backend database.
Select Submit. This should give you a response on the same page with an access token and an output indicating you successfully logged in to the database by using a managed identity and from a public IP address.

Option 2: Deploy directly from your workstation

You can use the bash script below to deploy the necessary resources directly from your workstation using the Azure CLI.

This script also generates a dbuser.sql file which you can use to grant the managed identity of the web app access to the database (for example, using sqlcmd or the SQL query editor in the Azure portal).

#!/bin/bash

# Define parameters.
RESOURCE_GROUP=appsvcnetworkingdemo
LOCATION=westus
SUBSCRIPTION_ID=<YOUR SUBSCRIPTION ID>

# Log in.
az login

az account list -o table
az account set -s $SUBSCRIPTION_ID

# Create the deployment resource group.
az group create --name $RESOURCE_GROUP --location "$LOCATION"

# Download the deployment bicep file (Azure CLI cannot deploy remote bicep files today).
wget https://raw.githubusercontent.com/Azure-Samples/app-service-networking-samples/main/deploy/main.bicep

# Get current user information for setting up SQL admin.
AAD_USERNAME=$(az ad signed-in-user show --query userPrincipalName --output tsv)
AAD_SID=$(az ad signed-in-user show --query id --output tsv)

# Deploy the bicep file.
az deployment group create \
  --name $RESOURCE_GROUP \
  --resource-group $RESOURCE_GROUP \
  --template-file ./main.bicep \
  --parameters name=$RESOURCE_GROUP aadUsername=$AAD_USERNAME aadSid=$AAD_SID

# Retrieve the name of the App Service managed identity.
APPSVC_IDENTITY=$(az deployment group show \
  --resource-group $RESOURCE_GROUP \
  --name $RESOURCE_GROUP \
  --query properties.outputs.principalId.value --output tsv)

# Create a SQL file to execute on the database which grants access to the App Service managed identity.
cat <<EOT> dbuser.sql
CREATE USER [$APPSVC_IDENTITY] FROM EXTERNAL PROVIDER;
ALTER ROLE db_datareader ADD MEMBER [$APPSVC_IDENTITY];
ALTER ROLE db_datawriter ADD MEMBER [$APPSVC_IDENTITY];
ALTER ROLE db_ddladmin ADD MEMBER [$APPSVC_IDENTITY];
GO;
EOT

# Optional: allow the local IP address to pass through the SQL firewall.
SQLSERVER_NAME=$(az deployment group show \
  --resource-group $RESOURCE_GROUP \
  --name $RESOURCE_GROUP \
  --query properties.outputs.sqlserverName.value --output tsv)
LOCAL_IP="`wget -qO- http://ipinfo.io/ip`"
az sql server firewall-rule create \
  --resource-group $RESOURCE_GROUP \
  --server $SQLSERVER_NAME \
  --name AllowLocalIP \
  --start-ip-address $LOCAL_IP \
  --end-ip-address $LOCAL_IP

# MANUAL ACTION:
# Use sqlcmd or the SQL query editor in the Azure portal to execute the above SQL file on the database.

Demos

These demos work best if you follow them one by one. They walk you through a full setup going from using out of the box networking to the options you have for extra locking down app service for incoming requests and next for outgoing requests.

rbnmtnez/app-service-networking-samples

App Service Networking Samples

Features

Getting Started

Prerequisites

Installation

Option 1: Using GitHub Actions

Option 2: Deploy directly from your workstation

Demos

Locking down incoming traffic

Locking down outgoing traffic

Special case

Resources

Azure Architecture Center

App Service Docs

WAF

Azure SQL Docs

Networking