Java - Demo Web Application

This is a simple Java web app built using Spring Boot and OpenJDK 11.

The app has been designed with cloud native demos & containers in mind, in order to provide a real working application for deployment, something more than "hello-world" but with the minimum of pre-reqs. It is not intended as a complete example of a fully functioning architecture or complex software design.

Typical uses would be deployment to Kubernetes, demos of Docker, CI/CD (build pipelines are provided), deployment to cloud (Azure) monitoring, auto-scaling

The app has several basic pages accessed from the top navigation menu, some of which are only lit up when certain configuration variables are set (see 'Optional Features' below):

Features:

• The 'Info' page displays some system basic information (OS, platform, CPUs, IP address etc) and should detect if the app is running as a container or not.
• The 'Tools' page is useful in demos, and has options such a forcing CPU load (for autoscale demos), and error pages for use with App Insights
• The 'mBeans' page is a basic Java mBeans explorer, letting you inspect mBeans registered with the JVM and the properties they are exposing
• Azure AD integration for user auth and sign-in (optional, see config below)
• Azure App Insights for monitoring (optional, see config below)

Status

Live instances:

Building & Running Locally

Pre-reqs

• Be using Linux, WSL or MacOS, with bash, make etc
• Java 11+ - for running locally, linting, running tests etc
• Docker - for running as a container, or image build and push
• Azure CLI - for deployment to Azure

Clone the project to any directory where you do development work

git clone https://github.com/benc-uk/java-demoapp.git

Makefile

A standard GNU Make file is provided to help with running and building locally.

help                 💬 This help message
lint                 🔎 Lint & format, will not fix but sets exit code on error
lint-fix             📜 Lint & format, will try to fix errors and modify code
image                🔨 Build container image from Dockerfile
push                 📤 Push container image to registry
run                  🏃 Run the server locally using Python & Flask
deploy               🚀 Deploy to Azure Web App
undeploy             💀 Remove from Azure
test                 🎯 Unit tests for server and frontend
test-report          🎯 Unit tests for server and frontend (with report output)
test-api             🚦 Run integration API tests, server must be running
clean                🧹 Clean up project

Make file variables and default values, pass these in when calling make, e.g. make image IMAGE_REPO=blah/foo

Makefile Variable	Default
IMAGE_REG	ghcr.io
IMAGE_REPO	benc-uk/java-demoapp
IMAGE_TAG	latest
AZURE_RES_GROUP	temp-demoapps
AZURE_REGION	uksouth
AZURE_SITE_NAME	java-{git-sha}

The application listens on port 8080 by default, but this can be set with the PORT environmental variable.

Containers

Public container image is available on GitHub Container Registry

Run in a container with:

docker run --rm -it -p 8080:8080 ghcr.io/benc-uk/java-demoapp:latest

Should you want to build your own container, use make image and the above variables to customise the name & tag.

Kubernetes

The app can easily be deployed to Kubernetes using Helm, see deploy/kubernetes/readme.md for details

Optional Features

Application Insights

If you wish to enable Azure App Insights integration set the azure_applicationinsights_instrumentationkey environmental variable to the relevant workspace key

User Sign-In - Azure Active Directory

The 'Spring Boot Starter for Azure Active Directory' is included in the application and the main application nav bar has a 'User' button which when configured will sign users in via Azure AD. This is optional and not required for the app to start and run.

NOTE. The Azure AD application must be registered with a reply/redirect URL which ends with /login/oauth2/code/, and have implicit grant enabled. The application must also be granted admin consent to several Graph APIs, this can limit which tenants the application can be registered in.

See the Azure docs for more details https://docs.microsoft.com/en-us/azure/developer/java/spring-framework/configure-spring-boot-starter-java-app-with-azure-active-directory

If running locally you can enabled Azure AD authentication by setting the following three environmental variables, before running make run

export azure_activedirectory_clientid='my-client-id'
export azure_activedirectory_clientsecret='my-secret'
export azure_activedirectory_tenantid='my-tenant'

GitHub Actions CI/CD

A working set of CI and CD release GitHub Actions workflows are provided .github/workflows/, automated builds are run in GitHub hosted runners

GitHub Actions

Updates

• Mar 2021 - Version bumps, unit tests
• Dec 2019 - First version