Docker (Ubuntu, Linux) – #ERROR: Couldn’t connect to Docker daemon at http+docker://localhost – is it running?

it’s means in many times(%95), your user not under docker group placed, or your post-install (docker group, user actions etc. steps) not completely done yet. For temporary fix, you can your docker/docker-compose command with sudo run.

kzorloglu@kzorloglu:~/projects/chameleon$ composer up
#ERROR: Couldn't connect to Docker daemon at http+docker://localhost - is it running?

If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.

to

kzorloglu@kzorloglu:~/projects/chameleon$ sudo composer up