Extract POM version, for a job from Github Actions - github-actions

Question

I am trying to test with Github Actions to build my docker container automatically.
In my POM, the version of the docker image that I create with JIB, I extract it from the version of my project.
<groupId>io.xxx.my-proyect</groupId>
<artifactId>my-proyect</artifactId>
<version>0.2.0-SNAPSHOT</version>
<name>my-proyect</name>
...
<plugin>
<groupId>com.google.cloud.tools</groupId>
....
<to>
<image>XXX/my-proyect:${version}</image>
</to>
</plugin>
Github Actions:
- name: package
run: ./mvnw package jib:dockerBuild
- name: push
run: docker push xxx/my-proyect:VERSION (<-- Extract from version property of my POM)
Anyone have any idea how to do it.

Answer 1

You can ask Maven using maven-help-plugin:
mvn help:evaluate -Dexpression=project.version -q -DforceStdout
If the command prints nothing (because -q suppresses all output including the evaluated version), then it's probably because the maven-help-plugin being used is too old. If so, you can pin the version like this:
mvn org.apache.maven.plugins:maven-help-plugin:3.2.0:evaluate -Dexpression=project.version -q -DforceStdout
Or, you could pin the version 3.2.0 in your pom.xml or in a parent pom.xml (if applicable).
Note that running a Maven command always takes some time, so it may add a few seconds to your build time. Passing --offline may help if it works (or may not so much).
Alternatively, you could run jib:build instead of jib:dockerBuild to have Jib directly push to xxx/my-project:VERSION. Looking at your YAML, there does not seem any good reason to run jib:dockerBuild followed by docker push. Using jib:build in this case will substantially cut your build time, as Jib loses a lot of performance optimizations when pushing to a local Docker daemon.
UDPATE: also, unless you are using Jib's <containerizingMode>packaged configuration, you don't need mvn package. mvn compile jib:... will suffice (and marginally faster).