maven built dockerized project that runs a node application - docker

Question

I have a project that is built via maven, its a dockerized project for a node application.
I want to be able to customize my CMD/EntryPoint based on the maven build arguments.
I know that when we do docker run and provide it the arguments it is accepted and that works fine.
but I want to do the same thing from maven commandline.
Is there a way to let docker run know the argument passed in the maven commandline?
or even better can I edit the dockerfile and read commandline args of maven and use in the dockerfile ENTRYPOINT?
Thanks in advance,
Minakshi

Answer 1

Based on this, you can either use maven-resources-plugin to replace instances of ${...} with the values set in maven before you build the docker file.
Example:
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
<executions>
<execution>
<id>filter-dockerfile</id>
<phase>generate-resources</phase>
<goals>
<goal>copy-resources</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}</outputDirectory>
<resources>
<resource>
<directory>src/main/docker</directory>
<filtering>true</filtering>
</resource>
</resources>
</configuration>
</execution>
</executions>
This assume your docker file is under src/main/docker/ path. The replaced docker file will be copied on ${project.build.directory} path.
Or based on this comment, you could pass arguments to docker file.
Example:
On your maven docker plugin
<configuration>
<buildArgs>
<artifactId>${project.artifactId}</artifactId>
<groupId>${project.groupId}</groupId>
</buildArgs>
</configuration>
Then access those properties as ARGs on docker file
ARG artifactId
ARG groupId
ENV ARTIFACT_ID=${artifactId} GROUP_ID=${groupId}
Hope this help answer you question.

Answer 2

Thank you for the responses
I used the resource filtering in maven to solve my problem:
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<userdefvariable></userdefvariable> // variable that you want to pass along
</properties>
<build>
<resources>
<resource>
<directory>src/main/resource</directory> // path to the file (can be anything)
<filtering>true</filtering> // must be true this is what does replacement
</resource>
</resources>
</build>
add to maven commands: "resources:resources -Duserdefvariable=value"
//this setup generates a file in target folder after running the mvn commands, where the variable is injected with the value given by the user.
in Dockerfile now you can instead put in a command to run the file:
CMD ["sh", "path to the script in target folder"]
// in this script should be the commands that you want to use