Test Container test cases are failing due to "Could not find a valid Docker environment"

If you're using MAC, in my case, to solve the problem I had to add a link.

Follow the command below:

sudo ln -s $HOME/.docker/run/docker.sock /var/run/docker.sock

In my case, this error was caused by root permission. If you are using ubuntu, docker wants permission to create a container and test-containers can not ask you for this permission at runtime. So you need to make docker runnable without sudo.

Try these steps to create a docker group and add a connected user:

$ sudo groupadd docker
$ sudo gpasswd -a $USER docker
$ sudo service docker restart

Try this in step 3 if you are using Ubuntu 14.04-15.10:

$ sudo service docker.io restart

After all, steps try some docker commands in the terminal without sudo like:

$ docker ps

If you are taking permission error, restart your computer, and then this must be fixed.

According to @AmyDoxy's suggestion, in addition to these steps, if the test container still can't find docker run the following command:

$ sudo chmod 666 /var/run/docker.sock

No other answers across the internet worked for me, likely because my case was somewhat unique. I am hoping this answer allows others in this weird, particular scenario to realize what is the problem.

So If:

1. You are on Linux
2. You are running your tests through an IDE
3. You installed IDE through flatpak, snap, or any other package manager that does sandboxing

The issue is that you are sandboxed by the package manager in the application. If you have a socket at /var/run/docker.sock (default), but the tests can't pick it up, this is why. That file does not exist in the sandbox, only on the host filesystem. Depending on the package manager, /var/run may be mounted inside the sandbox, so check your particular documentation. The most straightforward way to resolve this is to install the IDE outside of a sandbox via a tarball or some other thing.

I had a similar exception on my M1 Mac, when switching from Docker Desktop to Rancher Desktop. The approach suggested by @Wanderson Xesquevixos de Sique turned out to solve things, except that the path for symbolic linkage turned out to be different:

sudo ln -s ~/.rd/docker.sock /var/run/docker.sock

This issue also happens when your docker demon is not running. Starting it and running the tests again would fix the issue if it used to work before.

You can check weither docker is running by executing the following command in a shell

docker ps

If you are using Docker Desktop, simply check the flag "Allow the default Docker socket to be used" in Settings

It could be one of several issues:

• Unstable network connection as you suggested
• You have not logged in to dockerhub from your terminal

In my case I needed to also add my user to the docker user group as per this link:

• I also pulled the image before running the test, just in case.
• One more thing I had to do was to specify the image name when initialising the TestContainers instance as is shown below:

testcontainers tries to auto-detect how to connect to docker by inspecting the environment variable DOCKER_HOST or the file <user home>/.testcontainers.properties

In my case (Win10 + Docker Desktop on WSL2), I had to expose the docker daemon on tcp://localhost:2375 without TLS and then either: 1) set the environment variable and its value (in IDE or system) to DOCKER_HOST=tcp://localhost:2375 or 2) create the file <user home>/.testcontainers.properties and add this lines:

docker.host=tcp\://localhost\:2375
# This second line might be not completely necessary:
docker.client.strategy=org.testcontainers.dockerclient.EnvironmentAndSystemPropertyClientProviderStrategy

BTW, if you expose the daemon, it would be better if you restrict access to it from outside your machine, using the Windows Firewall (it's not sarcasm ;-) )

Testcontainers communicate to docker via sockets. In the newer version of Docker Desktop sockets are disabled by default.

This can be enabled Preferences -> Advanced -> "Enable default Docker socket (Requires password)"

I am using colima, and only this worked for me(2019 i9 mac).

export TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE=/var/run/docker.sock
export DOCKER_HOST=unix://${HOME}/.colima/docker.sock
sudo ln -s $HOME/.colima/docker.sock /var/run/docker.sock

Maybe you forgot start docker on your computer. This solved the problem for me.

If you are using colima, use

sudo ln -s $HOME/.colima/default/docker.sock /var/run/docker.sock

In my case , I have moved from Docker desktop to Rancher Desktop, and this command from @volkovs worked form

sudo ln -s $HOME/.rd/docker.sock /var/run/docker.sock

The official documentation will help you.

$ dockerd-rootless-setuptool.sh install

None of the solutions listed here did not work for me. I installed docker desktop, and docker.sock was not in /var/run/docker.sock.

So I had to find docker.sock using ss -x -a | grep docker.sock:

u_str LISTEN 0      4096                     /home/xxx/.docker/desktop/docker.sock 37055              * 0             
u_str ESTAB  0      0                        /home/xxx/.docker/desktop/docker.sock 5890598            * 5891857       
u_str ESTAB  0      0                        /home/xxx/.docker/desktop/docker.sock 44658              * 49293  

I found that the file was in $HOME/.docker/desktop/docker.sock.

So to make it work, I had to run sudo ln -s $HOME/.docker/desktop/docker.sock /var/run/docker.sock

Hope it helps you :)

I am using Colima with multiple profiles and this worked for me:

sudo ln -s $HOME/.colima/{profilename}/docker.sock /var/run/docker.sock

For people using a rootless Podman, TestContainers currently only officially support Docker. Given Podman's aim to be a stand-in replacement for Docker, it is however possible to use it with TestContainers:

# Enable the Podman socket
systemctl --user enable podman.socket --now

# This environment variable is used by TestContainers
export DOCKER_HOST=unix:///run/user/`id -u`/podman/podman.sock

# Ryuk needs to be disabled to avoid running root containers in Podman
export TESTCONTAINERS_RYUK_DISABLED=true

The systemctl command only needs to be executed once. (will still work after reboots) The two export commands can be added to your bashrc or similar shell configuration.

you should also check context if you are using wsl
docker context ls
if you see 2 context like this

NAME            DESCRIPTION                               DOCKER ENDPOINT                             ERROR
default        Current DOCKER_HOST based configuration   unix:///var/run/docker.sock                 
desktop-linux*   Docker Desktop                npipe:////./pipe/dockerDesktopLinuxEngine

you should choose default cause it's daemon inside wsl and it doesn't see windows containers
and second one it's common windows daemon and wsl use it like proxy and sometimes for example if you execute test container it will not see windows daemon

And also dont forget to set docker_host manually
export DOCKER_HOST=unix:///var/run/docker.sock

I had the same problem but only when I try to debug code. In my case the problem was too many breakpoints in Intellij. When I deleted all of them (especially from previous debuggings) and then put only one which I needed, the test container started normally. Maybe my response can be helpful in case when any other options don't work.

In my case, Docker Desktop wasn't able to pull images because the CPU usage was 100%. Restarting the PC fixed my issue,

I was facing the same issue. I added the below dependency

<dependency>
    <groupId>net.java.dev.jna</groupId>
    <artifactId>jna</artifactId>
    <version>5.13.0</version>
</dependency>

In my case (linux), when docker ps worked but my test containers test threw the IllegalStateException, the solution was setting the DOCKER_HOST env var.

export DOCKER_HOST='unix:///var/run/docker.sock' 

In case it's useful, this is the line in test containers throwing the exception. I debugged backward from there:

https://github.com/testcontainers/testcontainers-java/blob/f7973aa659d5f871c6ee4830d1a786a22b2ee876/core/src/main/java/org/testcontainers/dockerclient/DockerClientProviderStrategy.java#L275

which brought me here, where it's configuring its connection to test: https://github.com/testcontainers/testcontainers-java/blob/f7973aa659d5f871c6ee4830d1a786a22b2ee876/core/src/main/java/org/testcontainers/dockerclient/DockerClientProviderStrategy.java#L275

So it needed the docker host URI. Which brought me here: https://github.com/testcontainers/testcontainers-java/blob/f7973aa659d5f871c6ee4830d1a786a22b2ee876/core/src/main/java/org/testcontainers/dockerclient/DockerClientProviderStrategy.java#L275

Setting DOCKER_HOST to that URI solved the issue.

I face this problem everytime I reboot my laptop and then the next test execution of @SpringBootTest along with @Testcontainers will fail with below error

Caused by: 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:277)
    at java.base/java.util.Optional.orElseThrow(Optional.java:403)

Details in StackTrace will point out to the below code block which attempts to launch a container

@Container
static LocalStackContainer localStack = new LocalStackContainer(DockerImageName.parse(LOCAL_STACK_VERSION))
    .withServices(SQS, STS, DYNAMODB,IAM)
    .waitingFor(Wait.forLogMessage(".*Ready.*", 1)).withExposedPorts(4556)
    .withStartupTimeout(Duration.ofMinutes(1));

And the simple reason for that is, my docker desktop is not launched post reboot. So, if I simply launch Docker Desktop and its up and running, then tests launched successfully.

Because tests with such setup needs a docker environment to launch containers, pull image from docker hub and so on.

If this is a regular problem for you, then you can enable Start Docker Desktop when you sign in to your computer option

Make sure you have Docker Desktop running locally