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) []