Docker /usr/lib/systemd

• /usr/lib/systemd/system/docker.socket
• Docker /usr/lib/systemd Tutorial
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Many Linux distributions use systemd to start the Docker daemon. This documentshows a few examples of how to customize Docker’s settings.

Starting the Docker daemon

Once Docker is installed, you will need to start the Docker daemon.bash$ sudo systemctl start docker# or on older distributions, you may need to use$ sudo service docker startIf you want Docker to start at boot, you should also:bash$ sudo systemctl enable docker# or on older distributions, you may need to use$ sudo chkconfig docker on## Custom Docker daemon options

I have installed Docker with yum install docker: $ uname -a Linux caspgval4 3.10.0-229.20.1.el7.x8664 #1 SMP Wed Nov 4 10:08:36 CST 2015 x8664 x8664 x8664 GNU/Linux $ docker -version Docker. Nov 14, 2017 This is a bug report This is a feature request I searched existing issues before opening this one Expected behavior Docker should be started. Actual behavior Cannot start docker At CentOS 7. Good evening, I'm looking for the best way to move docker directory (default /var/lib/docker) to another directory. (Technically other disk partition) I'm using devicemapper, and I think a lot of things are mounted, so it's not as easy a. Okay so the problem was two-fold. One was that you (probably) have to change the dockerd group with -group, and also you have to change the docker.socket.service group as well. The other part is that you need to modify the settings with a systemd override ( sudo systemctl edit docker) rather than making changes in /lib/systemd.

There are a number of ways to configure the daemon flags and environment variablesfor your Docker daemon.

The recommended way is to use a systemd drop-in file (as described inthe systemd.unitdocumentation). These are local files named <something>.conf in the/etc/systemd/system/docker.service.d directory. This could also be/etc/systemd/system/docker.service, which also works for overridingthe defaults from /lib/systemd/system/docker.service.

However, if you had previously used a package which had anEnvironmentFile (often pointing to /etc/sysconfig/docker) then forbackwards compatibility, you drop a file with a .conf extension intothe /etc/systemd/system/docker.service.d directory including thefollowing:

To check if the docker.service uses an EnvironmentFile:

Alternatively, find out where the service file is located:

You can customize the Docker daemon options using override files as explained in theHTTP Proxy example below. The files located in /usr/lib/systemd/systemor /lib/systemd/system contain the default options and should not be edited.

Runtime directory and storage driver

You may want to control the disk space used for Docker images, containersand volumes by moving it to a separate partition.

In this example, we’ll assume that your docker.service file looks something like:

This will allow us to add extra flags via a drop-in file (mentioned above) byplacing a file containing the following in the /etc/systemd/system/docker.service.ddirectory:

You can also set other environment variables in this file, for example, theHTTP_PROXY environment variables described below.

To modify the ExecStart configuration, specify an empty configuration followedby a new configuration as follows:

If you fail to specify an empty configuration, Docker reports an error such as:

/usr/lib/systemd/system/docker.socket

HTTP proxy

This example overrides the default docker.service file.

If you are behind an HTTP proxy server, for example in corporate settings,you will need to add this configuration in the Docker systemd service file.

1. Create a systemd drop-in directory for the docker service:

2. Create a file called /etc/systemd/system/docker.service.d/http-proxy.confthat adds the HTTP_PROXY environment variable:

3. If you have internal Docker registries that you need to contact withoutproxying you can specify them via the NO_PROXY environment variable:

4. Flush changes:

5. Verify that the configuration has been loaded:

6. Restart Docker:

Docker /usr/lib/systemd Tutorial

Manually creating the systemd unit files

When installing the binary without a package, you may wantto integrate Docker with systemd. For this, simply install the two unit files(service and socket) from the githubrepositoryto /etc/systemd/system.

Docker /usr/lib/systemd Download