DOCKER_OPTS do not work in config file /etc/default/docker
I have changed /etc/default/docker with DOCKER_OPTS="-H tcp://127.0.0.1:2375 -H unix:///var/run/docker.sock" (docker version 1.4.1 in ubuntu 14.04), but it do not take any effect for me (not listening at port 2375 ). It seems that docker do not read this initial config file because I found export http_proxy enviroment do not work too. Only sudo docker -H tcp://127.0.0.1:2375 -H unix:///var/run/docker.sock -d works. It really confused me! According to docker documentation , The recommended way to configure the daemon flags and environment variables for your Docker daemon is to use a systemd