Tech notes on the go

Tuesday, July 7, 2015

Maven-style continuous delivery

Let's say you have a java program.
Also you have a continuous integration server,
that builds java jar file (artifact) and deploys it to artifactory
(or you just use mvn clean compile deploy to upload latest version to artifactory).

Let's say you also have a bunch of hosts that suppose to run the artifact.

How do you deploy (deliver) the artifact to all the hosts?

We'll use maven for that - exec:java goal and dependency management would help a lot.

On target hosts:

1. create file pom.xml (a bit of xml)

<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/maven-v4_0_0.xsd">

<artifactId>cool-program</artifactId>

<version>1.0-SNAPSHOT</version>

<dependencies>

<dependency>

<groupId>my.cool.sw</groupId>

<artifactId>my-cool-deployed-jar</artifactId>

<version>1.0-SNAPSHOT</version>

</dependency>

</dependencies>

</project>

2. exec

mvn exec:java -Dexec.mainClass="my.cool.sw.MainClass"

That's it.

No need to copy jar file to hosts each time sw is updated and uploaded to artifactory.
All the hosts would run latest possible version from artifactory.
Easy to automate and to maintain.

Thursday, June 11, 2015

Maven single jar with dependencies

just add the following to pom.xml file

<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>

</build>

and you run it with

mvn clean compile assembly:single

Compile goal should be added before assembly:single or otherwise the code on your own project is not included.

See more details in comments.

Commonly this goal is tied to a build phase to execute automatically. This ensures the JAR is built when executing mvn install or performing a deployment/release.

<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>

<phase>package</phase>

<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>

src: StackOverflow :-)