diff --git a/maven/content.md b/maven/content.md index b10caedcb..c518ad93d 100644 --- a/maven/content.md +++ b/maven/content.md @@ -6,28 +6,59 @@ # How to use this image -## Create a Dockerfile in your Maven project +You can run a Maven project by using the Maven Docker image directly, passing a Maven command to `docker run`: + +```console +$ docker run -it --rm --name my-maven-project -v "$(pwd)":/usr/src/mymaven -w /usr/src/mymaven %%IMAGE%%:3.3-jdk-8 mvn clean install +``` + +## Building local Docker image (optional) + +This is a base image that you can extend, so it has the bare minimum packages needed. If you add custom package(s) to the `Dockerfile`, then you can build your local Docker image like this: + +```console +$ docker build --tag my_local_%%IMAGE%%:3.5.2-jdk-8 . +``` + +# Reusing the Maven local repository + +The local Maven repository can be reused across containers by creating a volume and mounting it in `/root/.m2`. + + docker volume create --name maven-repo + docker run -it -v maven-repo:/root/.m2 %%IMAGE%% mvn archetype:generate # will download artifacts + docker run -it -v maven-repo:/root/.m2 %%IMAGE%% mvn archetype:generate # will reuse downloaded artifacts + +Or you can just use your home .m2 cache directory that you share e.g. with your Eclipse/IDEA: + +```console +$ docker run -it --rm -v "$PWD":/usr/src/mymaven -v "$HOME/.m2":/root/.m2 -v "$PWD/target:/usr/src/mymaven/target" -w /usr/src/mymaven %%IMAGE%% mvn clean package +``` + +# Packaging a local repository with the image + +The `$MAVEN_CONFIG` dir (default to `/root/.m2`) could be configured as a volume so anything copied there in a Dockerfile at build time is lost. For that reason the dir `/usr/share/maven/ref/` exists, and anything in that directory will be copied on container startup to `$MAVEN_CONFIG`. + +To create a pre-packaged repository, create a `pom.xml` with the dependencies you need and use this in your `Dockerfile`. `/usr/share/maven/ref/settings-docker.xml` is a settings file that changes the local repository to `/usr/share/maven/ref/repository`, but you can use your own settings file as long as it uses `/usr/share/maven/ref/repository` as local repo. ```dockerfile -FROM %%IMAGE%%:3.2-jdk-7-onbuild -CMD ["do-something-with-built-packages"] +COPY pom.xml /tmp/pom.xml +RUN mvn -B -f /tmp/pom.xml -s /usr/share/maven/ref/settings-docker.xml dependency:resolve ``` -Put this file in the root of your project, next to the pom.xml. +To add your custom `settings.xml` file to the image use -This image includes multiple ONBUILD triggers which should be all you need to bootstrap. The build will `COPY . /usr/src/app` and `RUN mvn install`. +```dockerfile +COPY settings.xml /usr/share/maven/ref/ +``` -You can then build and run the image: +For an example, check the `tests` dir + +# Running as non-root + +Maven needs the user home to download artifacts to, and if the user does not exist in the image an extra `user.home` Java property needs to be set. + +For example, to run as user `1000` mounting the host' Maven repo ```console -$ docker build -t my-maven . -$ docker run -it --name my-maven-script my-maven -``` - -## Run a single Maven command - -For many simple projects, you may find it inconvenient to write a complete `Dockerfile`. In such cases, you can run a Maven project by using the Maven Docker image directly, passing a Maven command to `docker run`: - -```console -$ docker run -it --rm --name my-maven-project -v "$PWD":/usr/src/mymaven -w /usr/src/mymaven %%IMAGE%%:3.2-jdk-7 mvn clean install +$ docker run -v ~/.m2:/var/maven/.m2 -ti --rm -u 1000 -e MAVEN_CONFIG=/var/maven/.m2 %%IMAGE%% mvn -Duser.home=/var/maven archetype:generate ```