Skip to content

Latest commit

 

History

History
155 lines (112 loc) · 8.58 KB

README.md

File metadata and controls

155 lines (112 loc) · 8.58 KB
Raw

Showcase for Event Sourcing on Quarkus using AxonFramework and MicroProfile

✨ Features

  • MicroProfile Standard
  • "Reactive" example using server sent events (SSE, tested with safari & chrome browser) and axon subscription query
  • Replay example. Use REST DELETE /nicknames/projection
  • Contains an axon upcaster example: NicknameChangedEventV1Upcaster.java
  • Works with H2 and PostgreSql. Just switch the regarding comments in application.properties and persistence.xml.
  • Uses Flyway for database schema creation and migration. It is configured to work with H2 and PostgreSql.
  • Uses JSON Binding to serialize JSON (MicroProfile Standard)
  • Uses meta-annotations to decouple AxonFramework from the message api and business code.
  • Full-Stack Build configuration including JavaScript Unit Tests with Jasmine, JavaScript minify, ...
  • Continuous Integration using GitHub Actions for a fully automated build including Java and JavaScript Unit Tests, Web Packaging, native image and integration-tests.

Notes

  • Code comments containing the marker Note: describes thoughts, background information, documented decisions and hints to problems.
  • ArchitectureRulesTest defines rules to assure low coupling between the business core, axon and microprofile features.
  • These rules might seem a bit extreme. Some may even find them to be impractical. After all, this examples shows that it can be done.
  • This is just a simple showcase, not an full application.

🚀 Getting started with H2 database

  • Clone or download this repository.
  • Open a terminal/command window.
  • Locate the h2 jar in your maven repository, e.g.: repository/com/h2database/h2/2.1.210/
  • Start the h2 database server using: java -cp h2-2.1.210.jar org.h2.tools.Server -tcp -tcpAllowOthers -ifNotExists
  • Without the h2 command argument -tcp the web console will be opened in the browser. Since the application uses the default user it won't work properly when the same user is logged in on the web console.
  • Open another terminal/command window. Don't close the one where the h2 server is running.
  • Open the directory where this README.md is located.
  • Run the application by using the following command: mvn compile quarkus:dev
  • (Optional) Use environment variable H2_HOST if the database runs on a different host than localhost.
  • Open the UI http://localhost:8080
  • (Optional) Use the postman collection "showcase-quarkus-eventsourcing.postman_collection.json" for service call examples.
  • (Optional) Use the unit tests inside the service package to replay nicknames, create new ones or create further accounts.

🚀 Getting started with PostgreSQL database

  • Clone or download this repository.
  • Open a terminal/command window.
  • Start PostgreSql database with (default) name "postgres" on port 5432. Details see application.properties.
  • Open the directory where this README.md is located.
  • Run the application by using the following command: mvn compile quarkus:dev -Dquarkus.profile=postgres
  • (Optional) Use environment variable POSTGRES_HOST if the database runs on a different host than localhost.
  • (Optional) Use environment variable POSTGRES_PORT if the database runs on a different port than 5432.
  • Open the UI http://localhost:8080
  • (Optional) Use the postman collection "showcase-quarkus-eventsourcing.postman_collection.json" for service call examples.
  • (Optional) Use the unit tests inside the service package to replay nicknames, create new ones or create further accounts.

🖼 Native Image

Native Image Build

Build a native image with mvn package -Pnative. Details see Building a native executable.

🩺 Native Image Agent

GraalVM's java command support additional line commands to gain insights to application that is running regarding how it can be compiled to a native image. More information about the native-image-agent can be found here: Assisted Configuration with Tracing Agent

Collect configuration data (manually)

The GraalVM java command can be used to collect configuration data for the native image:

$GRAALVM_HOME/bin/java -agentlib:native-image-agent=config-output-dir=native-image,caller-filter-file=native-image-caller-filter-rules.json -jar ./target/quarkus-app/quarkus-run.jar

This is helpful to get a hint on how to configure reflection-config.json and resources-config.json These files were created that way. Ideally, there would be an axon-extension for Quarkus that manages these settings at build time.

Notice

native-image-caller-filter-rules.json contains all known reflection calls that are already known and treated by Quarkus. Otherwise they would also appear in the reports and make them hard to read and interpret.

Collect configuration data (automated)

The maven profile "native-image-agent" is pre-configured to collect configuration data by running the integration tests with the necessary lineArgs automatically. Use the following command to start it:

mvn integration-test --activate-profiles native-image-agent

Notice

JAVA_HOME needs to be set to the home directory of a graalvm distribution before the maven command is used.

Trace reflection calls

The GraalVM java command can also be used to generate a trace of all reflection calls:

$GRAALVM_HOME/bin/java -agentlib:native-image-agent=trace-output=native-image/trace-output.json,caller-filter-file=native-image-caller-filter-rules.json -jar ./target/quarkus-app/quarkus-run.jar

Running integration tests

As described in Using GraalVM native-image-agent it is very helpful to use integration tests and run them against the running application, that was started by one of the commands above with the native image agent activated. This is much easier than clicking through the application manually.

🦶 Walkthrough

The Walkthrough lead you through the code and highlights most important code pieces from different angles.

What is AxonFramework?

Open source framework for event-driven microservices and domain-driven design

For more details please visit AxonFramework.

What is MicroProfile?

The MicroProfile® project is aimed at optimizing Enterprise Java for the microservices architecture.

For more details please visit MicroProfile

What is Quarkus?

A Kubernetes Native Java stack tailored for OpenJDK HotSpot and GraalVM, crafted from the best of breed Java libraries and standards.

For more details please visit Quarkus.

🔎 References