basics.md

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Basics	false	2

Basics

This page covers most of the common configs one might want to set on a Docker container. Please note that @Svc and @WebHealthCheck (or @TCPHealthCheck) are mandatory for each descriptor, so they will be present in each example.

Mounting a volume

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@Volume(host="/home/myuser/application.properties", container="/application.properties")
public class MyDescriptor {}

Useful but not quite enough for a test. Dockerunit supports mounting of resources from the test classpath.

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@Volume(host="application.properties", container="/application.properties", useClasspath=true)
public class MyDescriptor {}

The snippet above mounts the application.properties file from the src/test/resources directory inside your project.

This way you can easily mount different config files for different tests inside your Docker container.

Passing an environment variable

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@Env({"FOO=foo", "BAR=bar"})
public class MyDescriptor {}

This is equivalent to docker run -e FOO=foo -e BAR=bar my-docker-image

Exposing a container port to the host

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@PublishPort(host=9080, container=8080) 
public class MyDescriptor {}

This is equivalent to docker run -p 9080:8080 my-docker-image

Exposing a container port to a random host port (to avoid port conflicts)

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@PublishPorts
public class MyDescriptor {}

This is equivalent to docker run -P my-docker-image

Provide or override the command to execute once the container starts

import com.github.dockerunit.core.annotation.*;
import com.github.dockerunit.discovery.consul.annotation.*;

@Svc(name="my-service", image="my-docker-image")
@WebHealthCheck(port=8080)
@Command({"cat", "/etc/hosts"})
public class MyDescriptor {}

This is equivalent to docker run my-docker-image cat /etc/hosts

Need more to get started? Try looking at a full example.