Various improvements (#2)

* Add stats healthcheck
* Use openjdk-slim
* Add banner text
* Add example for JVM tool options

Dockerfile

@@ -1,7 +1,7 @@
-FROM openjdk:21
+FROM openjdk:21-slim
 
 WORKDIR .
 
 COPY ./build/peppol-bis-billing-validator--runner.jar .
 
-ENTRYPOINT ["java", "-Xmx512m", "-jar", "peppol-bis-billing-validator--runner.jar"]
+ENTRYPOINT ["java", "-jar", "peppol-bis-billing-validator--runner.jar"]

README.md

@@ -1,5 +1,5 @@
 # peppol-bis-billing-validator
-[![Generic badge](https://img.shields.io/badge/Version-0.1.0-important.svg)]()
+[![Generic badge](https://img.shields.io/badge/Version-0.2.0-important.svg)]()
 [![Generic badge](https://img.shields.io/badge/License-MIT-blue.svg)]()
 
 ## Introduction
@@ -23,6 +23,8 @@ XML.
     image: 'easybill/peppol-bis-billing-validator:latest'
     ports:
       - '8081:8080'
+    environment:
+        JAVA_TOOL_OPTIONS: -Xmx512m
     healthcheck:
       test: curl --fail http://localhost:8081/health || exit 0
       interval: 10s

src/main/java/io/github/easybill/Main.java

@@ -2,11 +2,25 @@
 
 import io.quarkus.runtime.Quarkus;
 import io.quarkus.runtime.annotations.QuarkusMain;
+import java.nio.charset.StandardCharsets;
 
 @QuarkusMain
 public class Main {
 
     public static void main(String[] args) throws Exception {
+        Main.printBannerText();
         Quarkus.run(args);
     }
+
+    private static void printBannerText() throws Exception {
+        try (var bannerStream = Main.class.getResourceAsStream("/banner.txt")) {
+            if (bannerStream == null) {
+                throw new Exception("could not read banner file");
+            }
+
+            System.out.println(
+                new String(bannerStream.readAllBytes(), StandardCharsets.UTF_8)
+            );
+        }
+    }
 }

src/main/java/io/github/easybill/PeppolValidatorApplication.java

@@ -9,7 +9,7 @@
 @OpenAPIDefinition(
     info = @Info(
         title = "Peppol Validator API",
-        version = "0.1.0",
+        version = "0.2.0",
         contact = @Contact(
             name = "easybill GmbH",
             url = "https://github.com/easybill",

src/main/java/io/github/easybill/Services/HealthCheck/StatsHealthCheck.java

@@ -0,0 +1,41 @@
+package io.github.easybill.Services.HealthCheck;
+
+import jakarta.enterprise.context.ApplicationScoped;
+import java.lang.management.ManagementFactory;
+import org.eclipse.microprofile.health.HealthCheck;
+import org.eclipse.microprofile.health.HealthCheckResponse;
+import org.eclipse.microprofile.health.HealthCheckResponseBuilder;
+import org.eclipse.microprofile.health.Liveness;
+
+@Liveness
+@ApplicationScoped
+public final class StatsHealthCheck implements HealthCheck {
+
+    @Override
+    public HealthCheckResponse call() {
+        HealthCheckResponseBuilder response = HealthCheckResponse.named(
+            "stats"
+        );
+
+        var osBean = ManagementFactory.getOperatingSystemMXBean();
+        var memBean = ManagementFactory.getMemoryMXBean();
+
+        return response
+            .up()
+            .withData("osName", osBean.getName())
+            .withData("osArch", osBean.getArch())
+            .withData(
+                "heapMemoryUsageMax",
+                memBean.getHeapMemoryUsage().getMax()
+            )
+            .withData(
+                "heapMemoryUsageCommitted",
+                memBean.getHeapMemoryUsage().getCommitted()
+            )
+            .withData(
+                "heapMemoryUsageUsed",
+                memBean.getHeapMemoryUsage().getUsed()
+            )
+            .build();
+    }
+}

src/main/resources/banner.txt

@@ -0,0 +1,7 @@
+
+                             ___.   .__.__  .__
+  ____ _____    _________.__.\_ |__ |__|  | |  |
+_/ __ \\__  \  /  ___<   |  | | __ \|  |  | |  |
+\  ___/ / __ \_\___ \ \___  | | \_\ \  |  |_|  |__
+ \___  >____  /____  >/ ____| |___  /__|____/____/
+     \/     \/     \/ \/          \/