DOCKER_OPTS do not work in config file /etc/default/docker

Question

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 14.0

Answer 1

In reply to the systemd comments in combination with Ubuntu: Ubuntu 14.04 still uses Upstart, so the changes to /etc/default/docker should have had the desired effect. It isn't until 15.04 that Ubuntu started using systemd by default.

In case you have Ubuntu 15.04 or later and thus need to use systemd, or if you explicitly choose to use systemd before 15.04, the correct and simplest way to get the desired effect of the OP, a TCP socket, would be:

1. Create the file /etc/systemd/system/docker.service.d/docker-tcp.conf
2. Add the contents below
3. Execute sudo systemctl daemon-reload
4. Execute sudo systemctl restart docker

File contents:

[Service]
ExecStart=
ExecStart=/usr/bin/docker daemon --host=tcp://127.0.0.1:2375