Basic

Dockerfile

@@ -1,7 +1,12 @@
-FROM openjdk:11.0.1-jre-slim-sid
+FROM maven:3.6-jdk-11-slim as BUILD
+COPY . /src
+WORKDIR /src
+RUN mvn install -DskipTests
 
-CMD ["/usr/bin/java", "-jar", "/app/app.jar"]
-
-# Add the service itself
-ARG JAR_FILE=demo-0.0.1-SNAPSHOT.jar
-COPY target/${JAR_FILE} /app/app.jar
+FROM openjdk:11.0.1-jre-slim-stretch
+EXPOSE 8080
+WORKDIR /app
+ARG JAR=hello-0.0.1-BASIC.jar
+
+COPY --from=BUILD /src/target/$JAR /app.jar
+ENTRYPOINT ["java","-jar","/app.jar"]

README.md

@@ -0,0 +1,113 @@
+# Spring Hello World
+
+This is a very basic Spring Hello World application that serves the value of the application property `message` via the web.
+
+## Quick Start
+
+Clone the repo down locally:
+
+```console
+git clone https://github.com/paulczar/spring-helloworld.git
+cd spring-hello-world
+```
+
+Assuming you have Java and Maven installed you can run it with:
+
+```console
+$ mvn spring-boot:run
+2019-02-27 15:08:41.186  INFO 29802 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
+2019-02-27 15:08:41.420  INFO 29802 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
+2019-02-27 15:08:41.426  INFO 29802 --- [           main] net.paulcz.hello.Application             : Started Application in 2.217 seconds (JVM running for 5.332)
+2019-02-27 15:08:55.500  INFO 29802 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
+2019-02-27 15:08:55.500  INFO 29802 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
+2019-02-27 15:08:55.506  INFO 29802 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 5 ms
+```
+
+Point your web browser or use wget/curl/httpy at `localhost:8080`:
+
+```console
+$ http localhost:8080
+HTTP/1.1 200
+Content-Length: 17
+Content-Type: text/plain;charset=UTF-8
+Date: Wed, 27 Feb 2019 21:13:35 GMT
+
+hello development
+```
+
+## Build and Run
+
+### With Maven
+
+```console
+$ mvn clean install
+...
+...
+[INFO] --- maven-jar-plugin:3.1.1:jar (default-jar) @ hello ---
+[INFO] Building jar: /home/user/development/spring/hello/target/hello-0.0.1-BASIC.jar
+[INFO] ------------------------------------------------------------------------
+[INFO] BUILD SUCCESS
+[INFO] ------------------------------------------------------------------------
+[INFO] Total time: 3.238 s
+[INFO] Finished at: 2019-02-27T15:15:42-06:00
+[INFO] ------------------------------------------------------------------------
+```
+
+Then you can run it like so:
+
+> Note: the `MESSAGE` environment variable is not neccesary, but is instead showing that you can change the `message` property to get a different response when accessing the application.
+
+```console
+$ MESSAGE="hello world" java -jar target/hello-0.0.1-BASIC.jar
+
+  .   ____          _            __ _ _
+ /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
+( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
+ \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
+  '  |____| .__|_| |_|_| |_\__, | / / / /
+ =========|_|==============|___/=/_/_/_/
+ :: Spring Boot ::        (v2.1.3.RELEASE)
+
+2019-02-27 15:16:41.581  INFO 30710 --- [           main] net.paulcz.hello.Application             : Starting Application v0.0.1-SNAPSHOT on paulczar with PID 30710 (/home/pczarkowski/development/spring/hello/target/hello-0.0.1-SNAPSHOT.jar started by pczarkowski in /home/pczarkowski/development/spring/hello)
+2019-02-27 15:16:41.584  INFO 30710 --- [           main] net.paulcz.hello.Application             : The following profiles are active: development
+2019-02-27 15:16:42.862  INFO 30710 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
+2019-02-27 15:16:42.893  INFO 30710 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
+2019-02-27 15:16:42.893  INFO 30710 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.16]
+2019-02-27 15:16:42.904  INFO 30710 --- [           main] o.a.catalina.core.AprLifecycleListener   : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [/usr/java/packages/lib:/usr/lib/x86_64-linux-gnu/jni:/lib/x86_64-linux-gnu:/usr/lib/x86_64-linux-gnu:/usr/lib/jni:/lib:/usr/lib]
+2019-02-27 15:16:42.974  INFO 30710 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
+2019-02-27 15:16:42.974  INFO 30710 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1297 ms
+2019-02-27 15:16:43.266  INFO 30710 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
+2019-02-27 15:16:43.556  INFO 30710 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
+2019-02-27 15:16:43.561  INFO 30710 --- [           main] net.paulcz.hello.Application             : Started Application in 2.546 seconds (JVM running for 2.978)
+
+```
+
+### With Docker
+
+If you have Docker you can skip using Maven and Java and Build a docker image:
+
+```console
+$ docker build -t paulczar/spring-hello .
+...
+...
+Step 9/10 : COPY --from=BUILD /src/target/$JAR /app.jar
+ ---> 8dc7d3d7bde4
+Step 10/10 : ENTRYPOINT ["java","-jar","/app.jar"]
+ ---> Running in b96dbe5b88c0
+Removing intermediate container b96dbe5b88c0
+ ---> 5405805d6f47
+Successfully built 5405805d6f47
+Successfully tagged paulczar/spring-hello:latest
+```
+
+Run it:
+
+```console
+$ docker run --name spring-hello -d --rm -p 8080:8080 paulczar/spring-hello
+6d47dc1ea4833f1a68c6969d4969a74a4d656b9a85600fd089b3cf0ca9716b9d
+
+$ curl localhost:8080
+hello development
+
+$ docker rm -f spring-hello
+```

pom.xml

@@ -11,7 +11,7 @@
     </parent>
     <groupId>net.paulcz</groupId>
     <artifactId>hello</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
+    <version>0.0.1-BASIC</version>
     <name>hello</name>
     <description>Hello World App</description>
 
@@ -29,15 +29,6 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-        <!-- needed for spring kubernetes config reloads -->
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-actuator</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.cloud</groupId>
-            <artifactId>spring-cloud-starter-kubernetes-config</artifactId>
-        </dependency>
     </dependencies>
 
     <dependencyManagement>

src/main/java/net/paulcz/hello/Application.java

@@ -5,8 +5,6 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.cloud.context.refresh.ContextRefresher;
-import org.springframework.cloud.context.restart.RestartEndpoint;
 
 @SpringBootApplication
 @RestController

src/main/java/net/paulcz/hello/MyConfig.java

@@ -2,8 +2,6 @@
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.cloud.context.refresh.ContextRefresher;
-import org.springframework.cloud.context.restart.RestartEndpoint;
 
 @Configuration
 @ConfigurationProperties(prefix = "")

src/main/resources/application.yaml

@@ -1,9 +1,5 @@
 spring.profiles.active: development
-logging.level.org.springframework.cloud.kubernetes: DEBUG
 message: hello default
 ---
 spring.profiles: development
 message: hello development
----
-spring.profiles: kubernetes
-message: hello kubernetes

src/main/resources/bootstrap.yaml

@@ -1,8 +1,2 @@
 spring.application.name: hello
-spring.profiles: default,development,kubernetes
-spring.cloud.kubernetes.enabled: true
-spring.cloud.kubernetes.config.enabled: true
-spring.cloud.kubernetes.reload.enabled: true
-spring.cloud.kubernetes.reload.mode: event
-spring.cloud.kubernetes.reload.strategy: refresh
-management.endpoint.restart.enabled: true
+spring.profiles: default,development