[JAVA] Create a flyway jar with maven and docker build (migrate) with docker-maven-plugin

I'm pretty addicted to it, so I'll summarize it.

Docker-maven-plugin to use

docker-maven-plugin is released from the following two.

• fabric8io/docker-maven-plugin
• spotify/docker-maven-plugin

This time I used docker-maven-plugin of fabric8io.

to docker buid

buid has two modes.

1. Describe from and cmd in pom.xml and buy method
2. How to refer to another Dockerfile from pom.xml and buy it

Regarding 1, it is as follows.

<configuration>
  <images>
    <image>
      <alias>service</alias> 
      <name>fabric8/docker-demo:${project.version}</name>

      <build> 
         <from>java:8</from> 
         <assembly>
           <descriptor>docker-assembly.xml</descriptor> 
         </assembly>
         <cmd> 
            <shell>java -jar /maven/service.jar</shell>
         </cmd>
      </build>
    </image>
</configuration>

2 is as follows.

        <configuration>
          <images>
            <image>
              <name>${project.name}</name>
              <build>
                <dockerFileDir>${project.basedir}</dockerFileDir>
              </build>
            </image>
          </images>
        </configuration>

I chose the method of 2. The reason is

• When migrating, you need to have a sql file, but if you use method 1, you cannot COPY.

Create a Dockerfile directly under the project and specify the bid reference destination.

project/
  ┝src
  ┝Dockerfile
  ┝pom.xml

How to migrate using Dockerfile

Dockerfile

FROM amazoncorretto:11-alpine
COPY maven /maven/jar/
COPY ${flyway.sqldir}/V1__Initialize.sql sql/
COPY ${flyway.confdir}/flyway.conf conf/
CMD java -XX:MaxRAMPercentage=75 -jar \
    maven/jar/${project.name}-${project.version}.jar \
    -url=jdbc:mysql://host.docker.internal:${db.port}/${db.name} \
    -user=${db.username} \
    -password=${db.password} \
    -configFiles=conf/flyway.conf \
    -jarDirs="" \
    migrate

point

(1) Place the created jar in the second layer.

COPY maven /maven/jar/
COPY ${flyway.sqldir}/V1__Initialize.sql sql/
COPY ${flyway.confdir}/flyway.conf conf/

As a mechanism of flyway, when searching for sql and conf files, go to the folder two levels above. Make the directory structure as follows.

/
├sql
│ └V1__Initialize.sql
├conf
│ └flyway.conf
├maven
  └jar
    └flyway.jar

(2) Use properties of pom.xml when copying sql and conf files.

pom.xml

...
  <properties>
    <flyway.sqldir>${project.basedir}/src/main/resources/db/migration</flyway.sqldir>
    <flyway.confdir>${project.basedir}/src/local/resources</flyway.confdir>
  </properties>
...

If you write it directly in Dockerfile, it will refer to an unintended path. Fix the path declared and referenced in properties.

③ Remove famous files when creating flyway jar

pom.xml

...
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>3.2.1</version>
        <configuration>
          <filters>
            <filter>
              <artifact>*:*</artifact>
              <excludes>
                <exclude>META-INF/*.SF</exclude>
                <exclude>META-INF/*.DSA</exclude>
                <exclude>META-INF/*.RSA</exclude>
              </excludes>
            </filter>
...

Install the above plugin. Without this, a SecurityException will occur.

run migrate with docker run

mvn package docker:buid

A docker Image is created.

docker run ${project.name}

Is executed.

References

http://dmp.fabric8.io/#docker:build

https://stackoverflow.com/questions/43525202/how-to-copy-files-from-an-absolute-path-to-docker-image-using-docker-maven-plugi

https://www.tssol.net/blog/2019/10/26/java_lang_securityexception_invalid-signature-file-digest-for-manifest-main-attributes/

https://oboe2uran.hatenablog.com/entry/2015/10/21/120700