Signed-off-by: Sven Dowideit <SvenDowideit@docker.com>
3.2 KiB
page_title: Controlling and configuring Docker using Systemd page_description: Controlling and configuring Docker using Systemd page_keywords: docker, daemon, systemd, configuration
Controlling and configuring Docker using Systemd
Many Linux distributions use systemd to start the Docker daemon. This document shows a few examples of how to customise Docker's settings.
Starting the Docker daemon
Once Docker is installed, you will need to start the Docker daemon.
$ sudo systemctl start docker
# or on older distributions, you may need to use
$ sudo service docker start
If you want Docker to start at boot, you should also:
$ sudo systemctl enable docker
# or on older distributions, you may need to use
$ sudo chkconfig docker on
Custom Docker daemon options
There are a number of ways to configure the daemon flags and environment variables for your Docker daemon.
If the docker.service
file is set to use an EnvironmentFile
(often pointing to /etc/sysconfig/docker
) then you can modify the
referenced file.
Or, you may need to edit the docker.service
file, which can be in /usr/lib/systemd/system
or /etc/systemd/service
.
Runtime directory and storage driver
You may want to control the disk space used for Docker images, containers and volumes by moving it to a separate partition.
In this example, we'll assume that your docker.services
file looks something like:
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target docker.socket
Requires=docker.socket
[Service]
Type=notify
EnvironmentFile=-/etc/sysconfig/docker
ExecStart=/usr/bin/docker -d -H fd:// $OPTIONS
LimitNOFILE=1048576
LimitNPROC=1048576
[Install]
Also=docker.socket
This will allow us to add extra flags to the /etc/sysconfig/docker
file by
setting OPTIONS
:
OPTIONS="--graph /mnt/docker-data --storage btrfs"
You can also set other environment variables in this file, for example, the
HTTP_PROXY
environment variables described below.
HTTP Proxy
This example overrides the default docker.service
file.
If you are behind a HTTP proxy server, for example in corporate settings, you will need to add this configuration in the Docker systemd service file.
Copy file /usr/lib/systemd/system/docker.service
to /etc/systemd/system/docker/service
.
Add the following to the [Service]
section in the new file:
Environment="HTTP_PROXY=http://proxy.example.com:80/"
If you have internal Docker registries that you need to contact without
proxying you can specify them via the NO_PROXY
environment variable:
Environment="HTTP_PROXY=http://proxy.example.com:80/" "NO_PROXY=localhost,127.0.0.0/8,docker-registry.somecorporation.com"
Flush changes:
$ sudo systemctl daemon-reload
Restart Docker:
$ sudo systemctl restart docker
Manually creating the systemd unit files
When installing the binary without a package, you may want
to integrate Docker with systemd. For this, simply install the two unit files
(service and socket) from the github
repository
to /etc/systemd/system
.