beenull/moby
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Merge pull request #22763 from zreigz/doc-multiple-daemons

Browse source 
Add documentation for running multiple daemons
This commit is contained in:
Sven Dowideit 2016-06-02 18:01:02 -07:00
commit 9be8f04950
1 changed files with 56 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

56
docs/reference/commandline/dockerd.md
View file

@ -977,3 +977,59 @@ has been provided in flags and `cluster-advertise` not, `cluster-advertise`
can be added in the configuration file without accompanied by `--cluster-store`
Configuration reload will log a warning message if it detects a change in
previously configured cluster configurations.
## Running multiple daemons
> **Note:** Running multiple daemons on a single host is considered as "experimental". The user should be aware of
> unsolved problems. This solution may not work properly in some cases. Solutions are currently under development
> and will be delivered in the near future.
This section describes how to run multiple Docker daemons on a single host. To
run multiple daemons, you must configure each daemon so that it does not
conflict with other daemons on the same host. You can set these options either
by providing them as flags, or by using a [daemon configuration file](#daemon-configuration-file).
The following daemon options must be configured for each daemon:
```bash
-b, --bridge= Attach containers to a network bridge
--exec-root=/var/run/docker Root of the Docker execdriver
-g, --graph=/var/lib/docker Root of the Docker runtime
-p, --pidfile=/var/run/docker.pid Path to use for daemon PID file
-H, --host=[] Daemon socket(s) to connect to
--config-file=/etc/docker/daemon.json Daemon configuration file
--tlscacert="~/.docker/ca.pem" Trust certs signed only by this CA
--tlscert="~/.docker/cert.pem" Path to TLS certificate file
--tlskey="~/.docker/key.pem" Path to TLS key file
```
When your daemons use different values for these flags, you can run them on the same host without any problems.
It is very important to properly understand the meaning of those options and to use them correctly.
- The `-b, --bridge=` flag is set to `docker0` as default bridge network. It is created automatically when you install Docker.
If you are not using the default, you must create and configure the bridge manually or just set it to 'none': `--bridge=none`
- `--exec-root` is the path where the container state is stored. The default value is `/var/run/docker`. Specify the path for
your running daemon here.
- `--graph` is the path where images are stored. The default value is `/var/lib/docker`. To avoid any conflict with other daemons
set this parameter separately for each daemon.
- `-p, --pidfile=/var/run/docker.pid` is the path where the process ID of the daemon is stored. Specify the path for your
pid file here.
- `--host=[]` specifies where the Docker daemon will listen for client connections. If unspecified, it defaults to `/var/run/docker.sock`.
- `--config-file=/etc/docker/daemon.json` is the path where configuration file is stored. You can use it instead of
daemon flags. Specify the path for each daemon.
- `--tls*` Docker daemon supports `--tlsverify` mode that enforces encrypted and authenticated remote connections.
The `--tls*` options enable use of specific certificates for individual daemons.
Example script for a separate “bootstrap” instance of the Docker daemon without network:
```bash
$ docker daemon \
-H unix:///var/run/docker-bootstrap.sock \
-p /var/run/docker-bootstrap.pid \
--iptables=false \
--ip-masq=false \
--bridge=none \
--graph=/var/lib/docker-bootstrap \
--exec-root=/var/run/docker-bootstrap
```