Spring Boot 4 Actuator in production: endpoints, security, custom health indicators

Companion repository for the ankurm.com article. Every transcript in docs/output/
was produced by running this project; scripts/run-all.sh regenerates all of them.

Verified against Spring Boot 4.1.1 / Framework 7.0.9 / Security 7.1.1 /
Micrometer 1.17.1 / kafka-clients 4.2.1 on Temurin JDK 25.0.4.1+1.

pom.xml

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.springframework.boot</groupId>
+    <artifactId>spring-boot-starter-parent</artifactId>
+    <version>4.1.1</version>
+    <relativePath/>
+  </parent>
+
+  <groupId>com.ankurm</groupId>
+  <artifactId>actuator-production</artifactId>
+  <version>1.0.0</version>
+  <name>actuator-production</name>
+  <description>Spring Boot Actuator in production: endpoints, security, custom health indicators</description>
+
+  <properties>
+    <java.version>25</java.version>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-webmvc</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-actuator</artifactId>
+    </dependency>
+    <!-- Spring Boot 4 split RestClient out of the web starter. Without this, injecting
+         RestClient.Builder fails at startup with "required a bean of type
+         'org.springframework.web.client.RestClient$Builder' that could not be found".
+         See docs/02-boot-4-changes.md. -->
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-restclient</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-security</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-data-jpa</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.h2database</groupId>
+      <artifactId>h2</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.kafka</groupId>
+      <artifactId>kafka-clients</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.micrometer</groupId>
+      <artifactId>micrometer-registry-prometheus</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.security</groupId>
+      <artifactId>spring-security-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>