java.lang.IllegalStateException at DockerClientProviderStrategy.java when running Springboot test on Ubuntu

Found the answer on stackoverflow

https://stackoverflow.com/a/68663970

The issue is the current login user cannot access docker.

Open your terminal and enter the command below to give the required permission to the user to access docker directly.

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

Once it’s all done, then try below command without sudo to see if it works

$ docker ps

If not, then try to reboot your machine.