Download all dependencies, plugin dependencies, compilers, etc. with Maven?

Question

I'm baking a Docker image which runs a Maven task at runtime. It looks kind of like this:

ADD pom.xml /srv
ADD src /srv/src

WORKDIR /srv
RUN mvn dependencies:go-offline scala:testCompile

At runtime, I'm running mvn gatling:execute to run a load testing utility.

My POM looks like this:

<project>
  <dependencies>
        <dependency>
            <groupId>io.gatling</groupId>
            <artifactId>gatling-core</artifactId>
            <version>${gatling.version}</version>
        </dependency>
        <dependency>
            <groupId>io.gatling</groupId>
            <artifactId>gatling-http</artifactId>
            <version>${gatling.version}</version>
        </dependency>
        <dependency>
            <groupId>io.gatling</groupId>
            <artifactId>gatling-app</artifactId>
            <version>${gatling.version}</version>
        </dependency>
        <dependency>
            <groupId>io.gatling.highcharts</groupId>
            <artifactId>gatling-charts-highcharts</artifactId>
            <version>${gatling.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>${scala-maven-plugin.version}</version>
            </plugin>
            <plugin>
                <groupId>io.gatling</groupId>
                <artifactId>gatling-maven-plugin</artifactId>
                <version>${gatling-plugin.version}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>execute</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

What I want to have happen is that when I ultimately run mvn gatling:execute, I don't want to have to download any dependencies, I'd like them all baked into the image at build time.

However, even executing mvn dependencies:go-offline scala:testCompile doesn't get me all of the way there. Running gatling:execute still requires downloading more dependencies.

How can I download absolutely everything that Maven requires into my Docker image, so that no downloads at runtime are required?

Sruti

Have you tried binding the Gatling execution to a phase and see whether dependencies:go-offline picks it up? – Trephine

What do you suggest? I'm sorry, long day, not sure exactly what you mean. – Sruti

Something like <execution><phase>integration-test</phase><goals><goal>execute</goal></goals></execution> – Trephine

The problem is that I can't run gatling:execute without massively pwning an endpoint ;) – Sruti

That's understandable, but not a problem if you don't go past the mvn package phase. Regardless of that, did the maven dependency plugin find the Gatling dependencies if they are bound to a phase? – Trephine

@TrentBartlem Can you submit that as an answer as to how I should modify my pom? – Sruti

@NaftuliTzviKay what is your objective? Do you want to distribute this image (e.g. in the company), or do you want to use it as a build environment and you don't want to download the same stuff with every build? If it's the latter, you can put your maven repository directory in a docker volume. – Netherlands

@Netherlands I want to distribute a Docker image which runs mvn gatling:execute, but I'd like all of the dependencies to be compiled into the image at build-time, not at run-time. Waiting for Maven to download the internet at Docker container start time is something I'd like to avoid. – Sruti

I guess you mean dependency:go-offline, right? Normally, maven will check SNAPSHOT dependencies once per day. Do you have any? Also try forcing the offline mode when running execute: mvn -o gatling:execute. – Netherlands

@NaftuliTzviKay did what I suggested in my previous comment work for you? – Netherlands

Answer 1

You don't necessarily have to run the simulation with the maven plugin, do you? You can use maven to package a jar with all dependencies and execute the gatling runner from it.

Halland

I know. I needed something fast, I didn't want to muck around with the maven assembly plugin all day trying to get a Scala application packaged and running properly. – Sruti

Answer 2

You can download all dependencies using: mvn dependency:copy-dependencies

After this you all project's dependencies will be available in the ./target/dependency/ folder.

Condonation