Build on Micha Kops' Tech Notes

Package a Spring Boot App as RPM

Fri, 14 May 2021 00:00:00 +0200

Goals

Package a Spring Boot Service as RPM Package
Configure systemd integration
Add install/uninstall hooks to create users, directories etc.

Maven Setup

<?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>2.4.2</version>
    <relativePath/>
  </parent>
  <groupId>com.hascode</groupId>
  <artifactId>sample-app</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <name>sample-app</name>

  <properties>
    <java.version>11</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>
  </dependencies>

  <build>
    <plugins>
      <plugin> (1)
        <groupId>de.dentrassi.maven</groupId>
        <artifactId>rpm</artifactId>
        <version>1.5.0</version>
        <executions>
          <execution>
            <goals>
              <goal>rpm</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <packageName>sample-app</packageName>
          <skipSigning>true</skipSigning>
          <group>Application/Misc</group>
          <requires>
            <require>java-11-openjdk-headless</require> (2)
          </requires>
          <entries>
            <entry> (3)
              <name>/opt/sample-app</name>
              <directory>true</directory>
              <user>root</user>
              <group>root</group>
              <mode>0755</mode>
            </entry>
            <entry> (4)
              <name>/opt/sample-app/log</name>
              <directory>true</directory>
              <user>sample-app</user>
              <group>sample-app</group>
              <mode>0750</mode>
            </entry>
            <entry> (5)
              <name>/opt/sample-app/sample-app.jar</name>
              <file>${project.build.directory}/${project.build.finalName}.jar</file>
              <user>root</user>
              <group>root</group>
              <mode>0644</mode>
            </entry>
            <entry> (6)
              <name>/usr/lib/systemd/system/sample-app.service</name>
              <file>${project.basedir}/src/main/dist/sample-app.service</file>
              <mode>0644</mode>
            </entry>
          </entries>
          <beforeInstallation> (7)
            <file>${project.basedir}/src/main/dist/preinstall.sh</file>
          </beforeInstallation>
          <afterInstallation>
            <file>${project.basedir}/src/main/dist/postinstall.sh</file>
          </afterInstallation>
          <beforeRemoval>
            <file>${project.basedir}/src/main/dist/preuninstall.sh</file>
          </beforeRemoval>
          <license>All rights reserved</license>
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>

Creating a Windows Executable from a Jar using Maven

Tue, 07 Aug 2012 00:00:00 +0200

Often in the life of a developer there is the need to create a windows executable for a Java application that is build and packaged in a Jar file.

The following short example shows how to create an executable Jar first and a windows executable containing vendor information, a nice icon and other stuff afterwards by using a combination of the Maven Shade Plugin and the launch4j Plugin for Maven.

Integrating Groovy in your Maven builds using GMaven

Tue, 12 Jul 2011 00:00:00 +0200

Often ant tasks are used in Maven builds but wouldn’t it be more attractive to integrate the Groovy language into our build process?

GMaven is the answers to this problem and brings together Maven and Groovy. It allows us to execute Groovy scripts inline from our Maven configuration, from a local script or even from a remote location. In the following short examples I am going to show how to configure Maven to execute Groovy scripts from different locations.

Dependency management in Grails 1.2

Sun, 23 May 2010 00:00:00 +0200

Sometimes I get the impression that there are many Maven haters in the Groovy/Grails community – now with version 1.2 of the Grails framework they are able to abandon the evil satanic Grails Maven Plugin and embrace the neverending joys of a slim, nice, sexy dependency resolution dsl .. here we go .. lets define some dependencies wheee …

Our dependency configuration is defined in grails-app/config/BuildConfig.groovy as a property named grails.project.dependency.resolution:
```
grails.project.dependency.resolution = {
// here will be some dependencies
}
```

A look at Maven 3 alpha

Sat, 22 May 2010 00:00:00 +0200

We are all waiting for a stable release of Maven3 with following updates ..

faster, more performant .. save us time building our software and some precious memory ;)
improved artifact resolution api and plugin api
better osgi integration
a few bugfixes
no mixing of application dependencies and tooling dependencies
though it does not matter that much to me: polyglot features .. e.g.: “Writing your pom files in Groovy”
version-less parent elements for multi-module or multi-pom projects, no need to define the parent version in every submodule
better artifact resolution, which dependency or pom supplied which artifact to the outcome .. got that information from: “Splitter from the world of Java”

How to add a local lib directory to Maven

Thu, 18 Mar 2010 00:00:00 +0100

Sometimes there is a dependency not available at a remote repository and one is too lazy to set up a local maven repository – that’s when one adds a directory in the project structure and wants maven to find dependencies there.

Create a directory called “lib” in the project root

Add the following markup to the pom.xml inside the <repositories>-Tag (create if it does not exist):

<repository>
    <id>lib</id>
    <name>lib</name>
    <releases>
        <enabled>true</enabled>
        <checksumPolicy>ignore</checksumPolicy>
    </releases>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
    <url>file://${project.basedir}/lib</url>
</repository>

GitHub Snippets

Mon, 01 Mar 2010 00:00:00 +0100

GitHub Actions

Step to check variables and redistribute as env

The following step does ..

check of given variables are set, if not, exit with an error that is visible in the action’s log
provide the given input as environment variable in GITHUB_ENV

- name: configuration
      env:
        VAR1: ${{ needs.configure.outputs.something }}
        VAR2: ${{ vars.SOMETHING_OTHER }}/
        VAR3: "something_other_other"
      run: |
        for var in VAR1 VAR2 VAR3; do [ -n "${!var}" ] || { echo "$var is missing"; exit 1; }; echo "$var=${!var}" >> "$GITHUB_ENV"; done

GitLab Snippets

Mon, 01 Mar 2010 00:00:00 +0100

Generate AsciiDoc Documentation and Publish it with GitLab Pages

We setup a repository and add a directory named docs there .. this is the home of our AsciiDoc files.

We’re using asciidoctor/docker-asciidoctor as Docker image for tool provisioning

This is the .gitlab-ci.yml, we’re running the stage only when something in the docs directory has changed.

stages:
  - "Build docs"

# The name of the job activates the GitLab pages publication
pages:
  image: asciidoctor/docker-asciidoctor
  stage: "Build docs"
  tags:
    - build
  script:
    - sh ./gen_docs.sh
    - mv output public
  only:
    refs:
      - master
    changes:
      - /docs/*
  artifacts:
    paths:
      - public
    expose_as: 'Documentation Archive'

Maven Snippets

Mon, 01 Mar 2010 00:00:00 +0100

Extract Coordinates from the POM

Helpful for build and integration environments, pipelines etc.

Exctract the Project version from the pom.xml

mvn org.apache.maven.plugins:maven-help-plugin:3.1.0:evaluate -Dexpression=project.version -q -DforceStdout

Override a Property via local configuration

e.g. to override the property xxx from your project’s pom.xml

Create a directory .mvn in your project directory root
Create a file named maven.config in this directory
Insert -Dxxx=newvalue into the file to override this property

Don’t forget to add .mvn to your .gitignore!