Gitlab-runner docker executor trying to download maven dependencies - docker

Question

I've got a gitalb-runner running as a docker container.
This is my failed job for a mvn test command:
Running with gitlab-runner 10.4.0 (857480b6)
on mvn-build (ae93a255)
Using Docker executor with image maven:3.3.9-jdk-8 ...
Using docker image sha256:b4b185fdfd711067c07e8a1df1257645aff2781402dc147e52d9a09636f9a139 for predefined container...
Pulling docker image maven:3.3.9-jdk-8 ...
Using docker image maven:3.3.9-jdk-8 ID=sha256:9997d8483b2fc521a4159feab922546dda0c5c22b5084f86dfab48f123ae4364 for build container...
Running on runner-ae93a255-project-2-concurrent-0 via 49682264df2f...
Fetching changes...
HEAD is now at e197d19 Fixed yml
Checking out e197d191 as dev...
Skipping Git submodules setup
$ echo "Building project with maven"
Building project with maven
$ mvn $MAVEN_OPTS test
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building rest-client
[INFO] ------------------------------------------------------------------------
Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-resources-plugin/2.6/maven-resources-plugin-2.6.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 21.626 s
[INFO] Finished at: 2018-02-21T15:00:07+00:00
[INFO] Final Memory: 9M/118M
[INFO] ------------------------------------------------------------------------
[ERROR] Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-resources-plugin:jar:2.6: Could not transfer artifact org.apache.maven.plugins:maven-resources-plugin:pom:2.6 from/to central (https://repo.maven.apache.org/maven2): Connect to repo.maven.apache.org:443 [repo.maven.apache.org/151.101.12.215] failed: Connection refused (Connection refused) -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResolutionException
ERROR: Job failed: exit code 1
My question is do I really need to set up a proxy and have an internet connection?
Or there is any other option to provide maven with that missing plugin?
I mention that I've already configured repo mapping in config.toml:
oncurrent = 1
check_interval = 0
[[runners]]
name = "mvn-build"
url = "http://192.168.233.128/"
token = "ae93a255f60d0e1abdb26cc9f72cd5"
executor = "docker"
[runners.docker]
tls_verify = false
image = "maven:3.3.9-jdk-8"
privileged = false
disable_cache = false
volumes = ["/cache","/var/run/docker.sock:/var/run/docker.sock","/root/.m2/repository/:/root/.m2/repository/"]
shm_size = 0
[runners.cache]

Answer 1

The Maven plugins are locally cached in the .m2/repository folder so you can make sure that all the needed plugins and dependencies are available in the /root/.m2/repository/ folder of the server/VM hosting the gitlab-runner. For example by running once the mvn test on the server.
You would probably want to avoid that as any time a dependency is changed you would need to ssh into the build server and update the local Maven cache there.
Considering this, setting up a proxy and internet connection once would not be that bad. Unless you have some other restrictions and/or would like to avoid downloading dependencies from external maven repos.
In this case maybe it is best to setup a maven repository within the organization which caches any external dependencies from Maven central