kayobe/doc/source/configuration/reference/docker-registry.rst

Docker registry

This section covers configuration of the Docker registry that may be deployed, by default on the seed host. Docker registry configuration is typically applied in ${KAYOBE_CONFIG_PATH}/docker-registry.yml. Consult the Docker registry documentation for further details of registry usage and configuration.

The registry is deployed during the kayobe seed host configure command.

Configuring the registry

docker_registry_enabled

Whether a docker registry is enabled. Default is false. When set to true, the Docker registry is deployed on all hosts in the docker-registry group. By default this includes the seed host.

docker_registry_env

Dict of environment variables to provide to the docker registry container. This allows to configure the registry by overriding specific configuration options, as described at https://docs.docker.com/registry/configuration/ For example, the registry can be configured as a pull through cache to Docker Hub by setting REGISTRY_PROXY_REMOTEURL to "https://registry-1.docker.io". Note that it is not possible to push to a registry configured as a pull through cache. Default is {}.

docker_registry_network_mode

The network mode used for the docker registry container. Default is host. When set to bridge, port mapping is configured to expose the registry through port docker_registry_port.

docker_registry_port

The port on which the docker registry server should listen. Default is 4000. When docker_registry_network_mode is set to host, configures the port used by the registry server inside the container. When docker_registry_network_mode is set to bridge, configures the overlay network port.

docker_registry_datadir_volume

Name or path to use as the volume for the docker registry. Default is docker_registry.

TLS

It is recommended to enable TLS for the registry.

docker_registry_enable_tls

Whether to enable TLS for the registry. Default is false.

docker_registry_cert_path

Path to a TLS certificate to use when TLS is enabled. Default is none.

docker_registry_key_path

Path to a TLS key to use when TLS is enabled. Default is none.

For example, the certificate and key could be stored with the Kayobe configuration, under ${KAYOBE_CONFIG_PATH}/docker-registry/. These files may be encrypted via Ansible Vault.

docker_registry_enable_tls: true
docker_registry_cert_path: "{{ kayobe_config_path }}/docker-registry/cert.pem
docker_registry_key_path: "{{ kayobe_config_path }}/docker-registry/key.pem

Basic authentication

It is recommended to enable HTTP basic authentication for the registry. This needs to be done in conjunction with enabling TLS for the registry: using basic authentication over unencrypted HTTP is not supported.

docker_registry_enable_basic_auth

Whether to enable basic authentication for the registry. Default is false.

docker_registry_basic_auth_htpasswd_path

Path to a htpasswd formatted password store for the registry. Default is none.

The password store uses a htpasswd format. The following example shows how to generate a password and add it to the kolla user in the password store. The password store may be stored with the Kayobe configuration, under ${KAYOBE_CONFIG_PATH}/docker-registry/. The file may be encrypted via Ansible Vault.

uuidgen | tr -d '\n' > registry-password
cat registry-password | docker run --rm -i --entrypoint htpasswd httpd:latest -niB kolla > $KAYOBE_CONFIG_PATH/docker-registry/htpasswd

Next we configure Kayobe to enable basic authentication for the registry, and specify the path to the password store.

docker_registry_enable_basic_auth: true
docker_registry_basic_auth_htpasswd_path: "{{ kayobe_config_path }}/docker-registry/htpasswd"

Using the registry

Enabling the registry does not automatically set the configuration for Docker engine to use it. This should be done via the docker_registry variable <configuration-hosts-docker>.

TLS

If the registry is using a privately signed TLS certificate, it is necessary to configure Docker engine with the CA certificate <configuration-hosts-docker>.

If TLS is enabled, Docker engine should be configured to use HTTPS to communicate with it:

docker_registry_insecure: false

Basic authentication

If basic authentication is enabled, Kolla Ansible needs to be configured with the username and password.

kolla_docker_registry_username: <registry username>
kolla_docker_registry_password: <registry password>