Can't connect to Docker running in WSL2 VM if Testcontainers runs on Windows and Docker Desktop is not used

[saurabh4studies]

Test container failed to start and throws Exception when try to run test case.

Host system: Windows 10
WSL2 based system: Ubuntu App for windows
Docker installed inside: Ubuntu App for windows

Using WSL2 based Ubuntu App on windows and setup docker in it. We are able to connect containers run inside it from host system i.e. Windows 10 through Ubuntu App IP address and port on which containers are running. In case of test containers it fails and throws below exception

Exception:

java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration

	at org.testcontainers.dockerclient.DockerClientProviderStrategy.lambda$getFirstValidStrategy$7(DockerClientProviderStrategy.java:215)
	at java.util.Optional.orElseThrow(Optional.java:290)
	at org.testcontainers.dockerclient.DockerClientProviderStrategy.getFirstValidStrategy(DockerClientProviderStrategy.java:207)
	at org.testcontainers.DockerClientFactory.getOrInitializeStrategy(DockerClientFactory.java:136)
	at org.testcontainers.DockerClientFactory.client(DockerClientFactory.java:178)
	at org.testcontainers.LazyDockerClient.getDockerClient(LazyDockerClient.java:14)
	at org.testcontainers.LazyDockerClient.authConfig(LazyDockerClient.java:12)
	at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:310)
	at infrastructure.DatabaseContainer.start(DatabaseContainer.java:30)
	at com.ecw.hplus.chat.ChannelFeatureShould.before(ChannelFeatureShould.java:70)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

Test case file:

import infrastructure.DatabaseContainer;
import infrastructure.MySqlDatabaseContainer;

import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

@RunWith(Parameterized.class)
public class AFeatureShould extends SimpleRepositoryTest {

    private static final MySqlDatabaseContainer mysql = new MySqlDatabaseContainer("mysql.sql");
    
    @Parameterized.Parameters
    public static DatabaseContainer[] getDatabaseContainer() {
        return new DatabaseContainer[]{
                mysql
        };
    }

    @BeforeClass
    public static void before() {
        mysql.start();
    }

    @Test
    public void test() {
        // assertions
    }
}

Tried to mitigate this issue by modifying /etc/docker/deamon.json and C:/Users/myuser/.testcontainers.properties files and not succeeded.

/etc/docker/deamon.json:

{
        "hosts": ["unix:///var/run/docker.sock", "tcp://127.0.0.1:2375"]
}

C:/Users/myuser/.testcontainers.properties:

docker.client.strategy=org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy
docker.host=tcp\://<ip-of-ubuntu-app>\:2375

[kiview]

Thanks for raising this issue @saurabh4studies.
Using Testcontainers from Windows, with manually installed Docker daemon in WSL2 (and without Docker Desktop) is currently not supported.

If you can't use Docker Desktop, I'd suggest running your tests from within WSL2 instead.

There might be ways to manually configure Testcontainers, Windows, Docker, and WSL2 to make your setup work, but we did not yet have time to dive into this topic.

[saurabh4studies]

Thanks for raising this issue @saurabh4studies. Using Testcontainers from Windows, with manually installed Docker daemon in WSL2 (and without Docker Desktop) is currently not supported.

If you can't use Docker Desktop, I'd suggest running your tests from within WSL2 instead.

There might be ways to manually configure Testcontainers, Windows, Docker, and WSL2 to make your setup work, but we did not yet have time to dive into this topic.

Thank you @kiview for your insights.

[xa4atur]

@saurabh4studies

Add these dependencies:

testImplementation 'org.testcontainers:testcontainers:1.16.3'
testImplementation 'org.testcontainers:junit-jupiter:1.16.3'
implementation 'com.github.docker-java:docker-java-api:3.2.8'

And change org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy to org.testcontainers.dockerclient.EnvironmentAndSystemPropertyClientProviderStrategy in .testcontainers.properties

docker.host=tcp\://127.0.0.1\:2375

[kiview]

Thanks for sharing this workaround @xa4atur. Are you sure you need to define implementation 'com.github.docker-java:docker-java-api:3.2.8'? This should not be necessary.

[artjomka]

Had similar issue, but with @kiview help was manage to resolve it.
Short summary:

implementation 'com.github.docker-java:docker-java-api:3.2.8' is not necessary

My .testcontainers.properties looks like this

docker.client.strategy=org.testcontainers.dockerclient.EnvironmentAndSystemPropertyClientProviderStrategy
docker.host=tcp\://127.0.0.1\:2375

Docker socket was located in different folder, so it was necessary to set TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE environment variable, in my case it was
TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE=/mnt/wsl/shared-docker/docker.sock

[xa4atur]

Thanks for sharing this workaround @xa4atur. Are you sure you need to define implementation 'com.github.docker-java:docker-java-api:3.2.8'? This should not be necessary.

Indeed, it is not necessary as docker-java-api is a transitive dependency: https://mvnrepository.com/artifact/org.testcontainers/testcontainers/1.16.0

[sz763]

I had faced with same issue. The following steps fixed it https://gist.github.com/sz763/3b0a5909a03bf2c9c5a057d032bd98b7, I hope it will help you.
UPD: saurabh4studies pay attention, you've incorrect file name deamon.json , it must be daemon.json.

[easterwood]

@saurabh4studies Which version of testcontainers did you used in this case?

[eddumelendez]

Closing due to it is resolved.

[mbuchner]

For me the issue was solved when I stopped using localhost (also tried 127.0.0.1) and used the eth0 address of WSL.

My Powershell script to set the DOCKER_HOST environment variable: (problem is that wsl ip is not static)

$wslip = ((wsl hostname -I) -split " ")[0]
$dockerhost = "tcp://" + $wslip + ":2375"
setx DOCKER_HOST $dockerhost
Write-Host "Set: setx DOCKER_HOST $dockerhost"
#get-childitem env:*
Read-Host -Prompt "Press Enter to exit"

[VVATOR]

Maybe my note might help someone...

How to make WSL Docker accessible from Windows host:

Run with Powershell (as admin):

  $dockerhost = "tcp://" + $wslip + ":2375"
  setx DOCKER_HOST $dockerhost
  Write-Host "Set: setx DOCKER_HOST $dockerhost"
  #get-childitem env:*
  Read-Host -Prompt "Press Enter to exit"

This command returns connection address like tcp://172.25.34.178:2375
Its address we should add to configuration c:\Users<user_name>.testcontainers.properties
that testcontainers used to connection with docker

docker.client.strategy=org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy
docker.host=tcp://172.25.34.178:2375

# docker.host it's internal wsl IP that should be configured to access in WSL 

In WSL terminal you should to add address from the previous step to /etc/docker/daemon.json
with come text editor

{
  "hosts": [
    "unix:///var/run/docker.sock", 
    "tcp://172.25.34.178:2375"
  ]
}

Restart wsl wih help PowerShell:

  wsl --shutdown
  wsl -l

Useful links:

• Fix the issue with listening docker from host in WSL
• How to install WSL
• DB Integration Tests with Spring Boot and Testcontainers