Java on App Service for Linux (Demo)

This project is a standalone demonstration of Java on Azure App Service for Linux. This is meant to be used by Microsoft employees to highlight the core features of the product.

Contents

• Requirements
• Preparation
• Demonstration Steps
• Pitching Notes
• Technical Notes

Requirements

Before working through this demo, you must have the following technologies on your machine.

• The Azure CLI
• An Azure account and subscription
• Maven (version 3 or greater)

Preparation

Complete these steps before meeting a customer or going to a conference.

1. Clone this project: git clone https://github.com/JasonFreeberg/java-app-service-demo.git

2. Provision a Resource Group and Cosmos DB account

   You can create the resources from the portal or using the CLI. The database name must be lowercase. For CLI users...

   az group create -n <your-azure-group-name> -l <your-resource-group-region>
   az cosmosdb create --kind GlobalDocumentDB -g <your-azure-group-name> -n <your-azure-documentDB-name>
   

   Get your database's URI from the Portal or from the JSON response if you used the CLI.

   Lastly, get the primaryMasterKey connection key:

   az cosmosdb list-keys -g <your-azure-group-name> -n <your-azure-documentDB-name>
   

3. Create an App Service instance and set up the scaling rules

   1. Create an App Service instance in the Portal with the following settings:

      • OS: Linux
      • Publish : Code
      • Runtime Stack: Tomcat 9.0 (JRE 8)

   2. Create a new App Service plan with a P1v2

      • If you have other applications in your plan, the scaling rules may not work as planned

   3. Set up scaling rules

      • Navigate to "Scale out (App Service plan)"
      • Click "Enable autoscale"
      • Click "Add Rule", and set the following for "Criteria":

      Field	Memory Rule	CPU Rule
      Time Aggregation	Minimum	Minimum
      Metric name	Memory Percentage	CPU Percentage
      Time grain statistic	Average	Minimum
      Operator	Greater than	Greater than
      Threshold	60	60
      Duration	5	5
      Operation	Increase instance count	Increase instance count
      Instance count	1	1
      Cool down (minutes)	5	5

4. Set the follwing environment variables on your local machine. Do not change these names. I suggest making these permanent environment variables (rather than the session current).

   • RESOURCE_GROUP: Name of your resource group
   • APP_SERVICE_NAME: Name of your App Service instance
   • DOCUMENTDB_URI: URI of your Cosmos DB
   • DOCUMENTDB_KEY: Primary key for Cosmos
   • DOCUMENTDB_DBNAME: Name of your Cosmos DB

5. Deploy the application!

   • Package and deploy the application: mvn clean package azure-webapp:deploy
   • We want to have it deployed ahead of the demo because the cold-start can take a few minutes. During the demo we will re-deploy the application, which saves time.

Demonstration Steps

1. Orient the audience with the project
   • It's a simple To-Do List application powered by Spring Boot on the backend, and AngularJS on the front.
   • The src directory is fairly lean. The controller class shows all the URL mappings.
   • Show the Azure plugin in the POM and note the following:
     • You only need to include the app name, resource group, and
     • The properties within the <appSettings> are set as environment variables when the app is deployed
2. Use the Maven plugin to deploy the application
   • mvn azure-webapp:deploy
   • While the deployment is happening, you can show the current version of the application in the browser
   • Create an entry or two
3. Navigate to the Portal
   • Under "Application Settings", show that the poperties from the POM plugin are now environment variables
   • Show the scaling rules in Portal
4. Test Cosmos and scaling rules
   • Make a record in Cosmos
   • Spam the buttons to stress-test the memory and CPU
5. Check on the instance count
   • In "Overview", we should see spikes for CPU and memory usage
   • Under "Scale out" the instance count should have increased
     • It may take a few minutes.
6. Finally, show the web SSH and log stream

Pitching Notes

• Using the Maven plugin for deployment
  • This is the primary story we are pushing for deploying Java applications to App Service. Note that they only need to specify their app service name, a resource group, and a runtime. That's it! If the app does not already exist, the plugin will create it!
• They can deploy a container and use the Azul JDK
  • Add Git repo with images
• Managed service for Java.
  • Upcoming feature to auto-update the JDK major/minor version, or stay at your current version
• Things not covered in this demo:
  • Site swaps
  • Jenkins CICD plugin
  • Application Insights

Technical Notes

• Underlying Linux OS?
• To run the app locally, you must have Tomcat locally installed with an enviornment variable, TOMCAT_HOME pointing to the tomcat directory. Then you can deploy to your lcoal tomcat using Maven: mvn clean package cargo:deploy.
  • Be sure to use the clean command if you are testing changes to the Javascript, otherwise your changes may not be packaged.
• Deploying with the WAR is faster because we can do hot deployments thanks to Tomcat
  • If you decide to package a JAR, it may be slower