rancherOS/docs/os/configuration/docker/index.md

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title: Configuring Docker in RancherOS layout: os-default

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Configuring Docker or System Docker

In RancherOS, you can configure System Docker and Docker daemons by using cloud-config.

Configuring Docker

In your cloud-config, Docker configuration is located under the rancher.docker key.

#cloud-config
rancher:
  docker:
    tls: true
    tls_args: [--tlsverify, --tlscacert=ca.pem, --tlscert=server-cert.pem, --tlskey=server-key.pem, '-H=0.0.0.0:2376']
    storage_driver: overlay

You can also customize Docker after it's been started using ros config.

$ sudo ros config set rancher.docker.storage_driver overlay

Valid Keys for Docker

Many of the standard Docker daemon arguments can be placed under the rancher.docker key. The command needed to start the Docker daemon will be generated based on these arguments. The following arguments are currently supported.

Key	Value
bridge	String
config_file	String
containerd	String
debug	Boolean
exec_root	String
group	String
graph	String
host	List
insecure_registry	List
live_restore	Boolean
log_driver	String
log_opts	Map where keys and values are strings
pid_file	String
registry_mirror	String
restart	Boolean
selinux_enabled	Boolean
storage_driver	String
userland_proxy	Boolean

In addition to the standard daemon arguments, there are a few fields specific to RancherOS.

Key	Value	Default	Description
extra_args	List of Strings	[]	Arbitrary daemon arguments, appended to the generated command
environment	List of Strings	[]
tls	Boolean	false	When setting up TLS, this key needs to be set to true.
tls_args	List of Strings (used only if tls: true)	[]
server_key	String (used only if tls: true)	""	PEM encoded server TLS key.
server_cert	String (used only if tls: true)	""	PEM encoded server TLS certificate.
ca_key	String (used only if tls: true)	""	PEM encoded CA TLS key.
storage_context	String	console	Specifies the name of the system container in whose context to run the Docker daemon process.

Configuring System Docker

In your cloud-config, System Docker configuration is located under the rancher.system_docker key.

#cloud-config
rancher:
  system_docker:
    storage_driver: overlay

Valid Keys for System Docker

All daemon arguments shown in the first table are also available to System Docker. The following are also supported.

Key	Value	Default	Description
extra_args	List of Strings	[]	Arbitrary daemon arguments, appended to the generated command
environment	List of Strings (optional)	[]