This charm provides a registry for storage and distribution of docker images. See https://docs.docker.com/registry/ for details.
Deployment
The registry is deployed as a stand alone application and supports integration with clients that implement the docker-registry interface.
Standalone Registry
For testing purposes, a simple, insecure registry can be deployed with:
juju deploy docker-registry
Secure Registry with TLS
This charm supports TLS via the tls-certificates relation. This can
be enabled by deploying and relating to a TLS provider, such as easyrsa:
juju deploy docker-registry
juju deploy easyrsa
juju add-relation easyrsa docker-registry
This charm also supports configuration-based TLS, which does not require a relation to a TLS provider. Instead, transfer required files and configure this charm as follows:
juju scp /my/local/ca.pem docker-registry/0:/home/ubuntu/ca.pem
juju scp /my/local/cert.crt docker-registry/0:/home/ubuntu/cert.crt
juju scp /my/local/cert.key docker-registry/0:/home/ubuntu/cert.key
juju config docker-registry \
tls-ca-path=/home/ubuntu/ca.pem \
tls-cert-path=/home/ubuntu/cert.crt \
tls-key-path=/home/ubuntu/cert.key
Finally, custom TLS data may be provided as base64-encoded config options to
the charm. The configured tls-*-blob data will be written to corresponding
configured tls-*-path files:
juju config docker-registry \
tls-ca-blob=$(base64 /path/to/ca) \
tls-cert-blob=$(base64 /path/to/cert) \
tls-key-blob=$(base64 /path/to/key)
Proxied Registry
This charm supports an http proxy relation that allows operators to
control how the registry is exposed on the network. This is achieved by
deploying and relating to a proxy provider, such as haproxy:
juju deploy docker-registry
juju deploy haproxy
juju relate haproxy docker-registry
Note: For juju 2.9.X
add-relationcommand must be used instead of relate.
When multiple docker-registry units are deployed, the proxy will be
configured with one unit chosen as the primary proxied service with remaining
units configured as backups. This provides a highly available deployment that
will fail over to a backup if the primary service becomes unavailable.
Note: HA deployments require the proxy to be in
active-passivepeering mode, which is the default forhaproxy.
TLS/SSL
TLS is supported between haproxy and docker-registry, though some manual
configuration is required. You will need to transfer the registry CA certificate
to the proxy so the registry certificate can be verified. The path to the
CA must match on both registry and proxy units. For example:
juju run --unit haproxy/$UNIT_NUM 'mkdir -p /etc/docker/registry'
juju run --unit haproxy/$UNIT_NUM 'chown ubuntu:ubuntu /etc/docker/registry'
juju scp docker-registry/$UNIT_NUM:/etc/docker/registry/ca.crt ./ca.crt
juju scp ./ca.crt haproxy/$UNIT_NUM:/etc/docker/registry
Nagios Monitoring
This charm supports monitoring with nagios:
juju deploy docker-registry
juju deploy nrpe --series bionic
juju relate docker-registry nrpe
Kubernetes Integration
See the Private Docker Registry documentation for details on integrating this charm with Kubernetes.
Actions
Adding Images
To make an image available in the deployed registry, it must be tagged and
pushed. This charm provides the push action to do this:
juju run-action --wait docker-registry/0 push \
image=<image> pull=<True|False> tag=<optional-tag-name>
This action will always tag and push a local image to the registry. By
specifying pull=True (the default), the action will first pull the
given image and subsequently tag/push it.
The default image tag is ‘net_loc/name:version’, where ‘net_loc’ is the
http-host config option or http[s]://[private-ip]:[port] if config is not
set. The image tag can be overriden by specifying the tag action parameter.
Listing Images
List images known to the registry with the images action:
juju run-action --wait docker-registry/0 images \
options=<extra-args> repository=<repository[:tag]>
This runs docker images on the registry machine. The optional options and
repository parameters are passed through to the underlying command. For
example, show non-truncated output with numeric image IDs:
juju run-action --wait docker-registry/0 images \
options="--no-trunc --quiet"
Removing Images
Remove images from the registry with the rmi action:
juju run-action --wait docker-registry/0 rmi \
options=<extra-args> image=<image [image...]>
This runs docker rmi on the registry machine. The image name (or space
separated names) must be specified using the image parameter. The optional
options parameter is passed through to the underlying command. For
example, remove the ubuntu:18.04 image without deleting untagged parents:
juju run-action --wait docker-registry/0 rmi \
options="--no-prune" image="ubuntu:18.04"
Starting/Stopping
The registry is configured to start automatically with the dockerd system service. It can also be started or stopped with charm actions as follows:
juju run-action --wait docker-registry/0 stop
juju run-action --wait docker-registry/0 start
Authentication
This charm supports basic (htpasswd) as well as token-based authentication. Configure either method as follows:
juju config docker-registry \
auth-basic-user='admin' \
auth-basic-password='redrum'
juju config docker-registry \
auth-token-issuer='auth.example.com' \
auth-token-realm='myorg' \
auth-token-root-certs='$(base64 /path/to/file)' \
auth-token-service='myapp'
Delete by digest
The recommended way to delete images from the registry is to use the rmi
action. If necessary, this charm can be configured to
allow deletion of blobs and manifests by digest by setting
the storage-delete config option to true:
juju config docker-registry storage-delete=true
Read-Only Mode
The registry can be switched to read-only mode by setting
the storage-read-only config option to true:
juju config docker-registry storage-read-only=true
This may be useful when performing maintenance or deploying an environment with complex authentication requirements.
As an example, consider a scenario that requires unauthenticated pull and authenticated push access to the registry. This can be achieved by deploying this charm twice with the same storage backend (for example, a Swift object storage cluster):
juju deploy docker-registry public --config <storage-swift-opts>
juju deploy docker-registry private --config <storage-swift-opts>
Configure the unauthenticated public registry to be read-only, and enable authentication for the private registry:
juju config public storage-read-only=true
juju config private <auth-opts>
With a common storage backend and appropriate configuration, unauthenticated public users have a read-only view of the images pushed by authenticated private users.
S3 Storage
The charm supports S3 or S3-compatible storage(like RADOS in CEPH), which may be configured in the following way:
juju config docker-registry \
storage-s3-region=<region> \
storage-s3-bucket=<bucket-name> \
storage-s3-secretkey=<secret-key> \
storage-s3-accesskey=<access-key>
Please note that the options above are required. All extra options can be found in configuration.yaml or on the charmhub configuration page.
Swift Storage
Note: Please note that Swift driver is deprecated and is not supported in new distribution versions.
The charm supports Swift configuration options that can be used to store images in a Swift backend:
juju config docker-registry \
storage-swift-authurl=<url> \
storage-swift-container=<container> \
storage-swift-password=<pass> \
storage-swift-region=<region> \
storage-swift-tenant=<tenant> \
storage-swift-username=<user>
Note: If any of the above config options are set, then they must all be set. Optional params are noted below.
It is possible to configure the swift backend with an OpenStack domain name for Identity v3. To enable this, set the following optional config parameter:
storage-swift-domain=<val>
Also note that if the swift container is empty, requests to the registry may return 503 errors like the following:
{"errors":[{"code":"UNAVAILABLE","message":"service unavailable","detail":"health check failed: please see /debug/health"}]}
Per Registry becomes permanently unavailable after 30 seconds, using S3 driver · Issue #2292 · distribution/distribution · GitHub, upload an empty file called “files” at the root of the container to workaround the issue.
For the swift driver configuration see here for more details.