archetype-resources.README.md Maven / Gradle / Ivy
#set( $symbol_pound = '#' )
#set( $symbol_dollar = '$' )
#set( $symbol_escape = '\' )
${symbol_pound} ${artifactId}
A dockerized Java standalone application with Maven build
[](https://www.apache.org/licenses/LICENSE-2.0.html)
[](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html)
${symbol_pound}${symbol_pound} What is this?
This project shows how to automate the creation of a Docker image with a Java command line application using Maven.
- Creates a docker image that runs a Java [main method](src/main/java/${pkgPath}/HelloWorld.java) on start of the container and terminates after the program is finished
- Example application that writes the environment variables from the Docker container to a test file.
- Also outputs some log statements
- Uses the fabric8 [maven-docker-plugin](https://github.com/fabric8io/docker-maven-plugin)
- Build the image
- Start a container for an [integration test](src/test/java/${pkgPath}/HelloWorldIT.java)
- Has a plain [Dockerfile](src/main/docker/Dockerfile) to configure the image
- Uses the [maven-dependency-plugin](https://maven.apache.org/plugins/maven-dependency-plugin/) to collect the JARs needed for the application
- Uses an [assembly.xml](src/main/assembly.xml) file to copy all files to the image
- Mounts a directory in the container as a volume to a host directory
- Uses the [system-maven-plugin](https://github.com/fuin/system-maven-plugin) to set the current user/group for the mount
- Uses [logback](https://logback.qos.ch/) for logging
- Creates a "logback.xml" configuration automatically if it does not exist. This allows a user to configure the log level for multiple runs of the container.
- Log file is created in the mounted directory of the host.
${symbol_pound}${symbol_pound} Build
Checkout the project and build it using the [Takari Maven Wrapper](https://github.com/takari/maven-wrapper).
Inside the root directory of the project type the following:
```
./mvnw clean verify
```
If this was successful you should see something like:
```
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
```
Verify that a Docker image was created:
```
docker images
```
The new image should be listed with two tags:
```
REPOSITORY TAG
${company}/${artifactId} 0.1.0-SNAPSHOT
${company}/${artifactId} latest
```
Now run the application by typing:
```
docker run ${symbol_escape}
--volume "${symbol_dollar}(pwd)"/data:/usr/src/${artifactId}/data ${symbol_escape}
--user ${symbol_dollar}UID:${symbol_dollar}UID ${symbol_escape}
--env my_var=abc123 ${symbol_escape}
${company}/${artifactId}
```
After running the container there should be three files in the [data](data) dircetory of the project:
```
hello-world.log
hello-world.txt
logback.xml
```