Spring Boot Actuator + Kubernetes

Issue: BAEL-2356

spring-cloud/spring-cloud-kubernetes/liveness-example/Dockerfile

@@ -0,0 +1,11 @@
+FROM openjdk:8-jdk-alpine
+
+# Create app directory
+RUN mkdir -p /usr/opt/service
+
+# Copy app
+COPY target/*.jar /usr/opt/service/service.jar
+
+EXPOSE 8080
+
+ENTRYPOINT exec java -jar /usr/opt/service/service.jar

spring-cloud/spring-cloud-kubernetes/liveness-example/pom.xml

@@ -0,0 +1,51 @@
+<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.5.17.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>liveness-example</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-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>

spring-cloud/spring-cloud-kubernetes/liveness-example/src/main/java/com/baeldung/liveness/Application.java

@@ -0,0 +1,12 @@
+package com.baeldung.liveness;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

spring-cloud/spring-cloud-kubernetes/liveness-example/src/main/java/com/baeldung/liveness/health/CustomHealthIndicator.java

@@ -0,0 +1,27 @@
+package com.baeldung.liveness.health;
+
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class CustomHealthIndicator implements HealthIndicator {
+
+    private boolean isHealthy = true;
+
+    public CustomHealthIndicator() {
+        ScheduledExecutorService scheduled = Executors.newSingleThreadScheduledExecutor();
+        scheduled.schedule(() -> {
+            isHealthy = false;
+        }, 30, TimeUnit.SECONDS);
+    }
+
+    @Override
+    public Health health() {
+        return isHealthy ? Health.up().build() : Health.down().build();
+    }
+}

spring-cloud/spring-cloud-kubernetes/liveness-example/src/main/resources/resources/application.properties

@@ -0,0 +1 @@
+server.port=8080

spring-cloud/spring-cloud-kubernetes/liveness-example/src/main/resources/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

spring-cloud/spring-cloud-kubernetes/liveness-example/src/test/java/com/baeldung/SpringContextIntegrationTest.java

@@ -0,0 +1,17 @@
+package com.baeldung;
+
+import com.baeldung.liveness.Application;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = Application.class)
+public class SpringContextIntegrationTest {
+
+	@Test
+	public void contextLoads() {
+	}
+
+}

spring-cloud/spring-cloud-kubernetes/object-configurations/liveness-example-k8s-template.yaml

@@ -0,0 +1,54 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: liveness-example
+spec:
+  selector:
+    app: liveness-example
+  ports:
+  - port: 8080
+
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: liveness-example
+spec:
+  selector:
+    matchLabels:
+      app: liveness-example
+  replicas: 1
+  strategy:
+    rollingUpdate:
+      maxUnavailable: 0
+  template:
+    metadata:
+      labels:
+        app: liveness-example
+    spec:
+      containers:
+      - name: liveness-example
+        image: dbdock/liveness-example:1.0.0
+        imagePullPolicy: IfNotPresent
+        resources:
+          requests:
+            memory: 400Mi
+            cpu: 400m
+        ports:
+        - containerPort: 8080
+        readinessProbe:
+          httpGet:
+            path: /health
+            port: 8080
+          initialDelaySeconds: 10
+          timeoutSeconds: 2
+          periodSeconds: 3
+          failureThreshold: 1
+        livenessProbe:
+          httpGet:
+            path: /health
+            port: 8080
+          initialDelaySeconds: 20
+          timeoutSeconds: 2
+          periodSeconds: 8
+          failureThreshold: 1

spring-cloud/spring-cloud-kubernetes/object-configurations/readiness-example-k8s-template.yaml

@@ -0,0 +1,54 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: readiness-example
+spec:
+  selector:
+    app: readiness-example
+  ports:
+  - port: 8080
+
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: readiness-example
+spec:
+  selector:
+    matchLabels:
+      app: readiness-example
+  replicas: 1
+  strategy:
+    rollingUpdate:
+      maxUnavailable: 0
+  template:
+    metadata:
+      labels:
+        app: readiness-example
+    spec:
+      containers:
+      - name: readiness-example
+        image: dbdock/readiness-example:1.0.0
+        imagePullPolicy: IfNotPresent
+        resources:
+          requests:
+            memory: 400Mi
+            cpu: 400m
+        ports:
+        - containerPort: 8080
+        readinessProbe:
+          httpGet:
+            path: /health
+            port: 8080
+          initialDelaySeconds: 40
+          timeoutSeconds: 2
+          periodSeconds: 3
+          failureThreshold: 5
+        livenessProbe:
+          httpGet:
+            path: /health
+            port: 8080
+          initialDelaySeconds: 100
+          timeoutSeconds: 2
+          periodSeconds: 8
+          failureThreshold: 1

spring-cloud/spring-cloud-kubernetes/pom.xml

@@ -11,6 +11,8 @@
     <modules>
         <module>demo-frontend</module>
         <module>demo-backend</module>
+        <module>liveness-example</module>
+        <module>readiness-example</module>
     </modules>
 
     <parent>

spring-cloud/spring-cloud-kubernetes/readiness-example/Dockerfile

@@ -0,0 +1,11 @@
+FROM openjdk:8-jdk-alpine
+
+# Create app directory
+RUN mkdir -p /usr/opt/service
+
+# Copy app
+COPY target/*.jar /usr/opt/service/service.jar
+
+EXPOSE 8080
+
+ENTRYPOINT exec java -jar /usr/opt/service/service.jar

spring-cloud/spring-cloud-kubernetes/readiness-example/pom.xml

@@ -0,0 +1,49 @@
+<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.5.17.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>readiness-example</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-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>

spring-cloud/spring-cloud-kubernetes/readiness-example/src/main/java/com/baeldung/readiness/Application.java

@@ -0,0 +1,12 @@
+package com.baeldung.readiness;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

spring-cloud/spring-cloud-kubernetes/readiness-example/src/main/java/com/baeldung/readiness/health/CustomHealthIndicator.java

@@ -0,0 +1,27 @@
+package com.baeldung.readiness.health;
+
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class CustomHealthIndicator implements HealthIndicator {
+
+    private boolean isHealthy = false;
+
+    public CustomHealthIndicator() {
+        ScheduledExecutorService scheduled = Executors.newSingleThreadScheduledExecutor();
+        scheduled.schedule(() -> {
+            isHealthy = true;
+        }, 40, TimeUnit.SECONDS);
+    }
+
+    @Override
+    public Health health() {
+        return isHealthy ? Health.up().build() : Health.down().build();
+    }
+}

spring-cloud/spring-cloud-kubernetes/readiness-example/src/main/resources/resources/application.properties

@@ -0,0 +1 @@
+server.port=8080

spring-cloud/spring-cloud-kubernetes/readiness-example/src/main/resources/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

spring-cloud/spring-cloud-kubernetes/readiness-example/src/test/java/com/baeldung/SpringContextIntegrationTest.java

@@ -0,0 +1,17 @@
+package com.baeldung;
+
+import com.baeldung.readiness.Application;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = Application.class)
+public class SpringContextIntegrationTest {
+
+	@Test
+	public void contextLoads() {
+	}
+
+}