moby/docs/sources/articles/configuring.md

page_title: Configuring Docker page_description: Configuring the Docker daemon on various distributions page_keywords: docker, daemon, configuration

Configuring Docker on various distributions

After successfully installing Docker, the docker daemon runs with it's default configuration. You can configure the docker daemon by passing configuration flags to it directly when you start it.

In a production environment, system administrators typically configure the docker daemon to start and stop according to an organization's requirements. In most cases, the system administrator configures a process manager such as SysVinit, Upstart, or systemd to manage the docker daemon's start and stop.

Some of the daemon's options are:

Flag	Description
-D, --debug=false	Enable or disable debug mode. By default, this is false.
-H,--host=[]	Daemon socket(s) to connect to.
--tls=false	Enable or disable TLS. By default, this is false.

The command line reference has the complete list of daemon flags.

Direct Configuration

If you're running the docker daemon directly by running docker -d instead of using a process manager, you can append the config options to the run command directly.

Here is a an example of running the docker daemon with config options:

docker -d -D --tls=false -H tcp://0.0.0.0:2375

These options :

• Enable -D (debug) mode
• Set tls to false
• Listen for connections on tcp://0.0.0.0:2375

Ubuntu

After successfully installing Docker for Ubuntu, you can check the running status using Upstart in this way:

$ sudo status docker
docker start/running, process 989

You can start/stop/restart docker using

$ sudo start docker

$ sudo stop docker

$ sudo restart docker

Configuring Docker

You configure the docker daemon in the /etc/default/docker file on your system. You do this by specifying values in a DOCKER_OPTS variable. To configure Docker options:

1. Log into your system as a user with sudo or root privileges.

2. If you don't have one, create the /etc/default/docker file in your system.

   Depending on how you installed Docker, you may already have this file.

3. Open the file with your favorite editor.

    $ sudo vi /etc/default/docker
   

4. Add a DOCKER_OPTS variable with the following options. These options are appended to the docker daemon's run command.

    DOCKER_OPTS=" --dns 8.8.8.8 --dns 8.8.4.4 -D --tls=false -H tcp://0.0.0.0:2375 "
   

These options :

• Set dns server for all containers
• Enable -D (debug) mode
• Set tls to false
• Listen for connections on tcp://0.0.0.0:2375

5. Save and close the file.

6. Restart the docker daemon.

     $ sudo restart docker
   

7. Verify that the docker daemon is running as specified wit the ps command.

    $ ps aux | grep docker | grep -v grep