Scaling out the docker registry

mattford63 · February 3, 2015, 7:01pm

I am looking to scale out a local stand-alone docker-registry for both HA and performance reasons.

A few questions:

can multiple containers point to the same S3 back-end
I assume the Redis cache can be the same for all containers?
how might search be affected?

Has anyone else done this?

Thanks for any pointers.

Kind regards,

Matt.

mattford63 · February 3, 2015, 7:27pm

After some research I’ve come up with the following plan:

Use Amazon Auto Scaling Groups to provision multiple Docker Registries via Docker then:

use a common S3 backend across the containers
use a common Elasticache (Redis) server across the containers
use a common RDS(mysql) SQLAlchemy end-point

The question is: is this sensible? Is it designed to work this way?

Many thanks for any pointers,

Matt.

alexnauda · March 3, 2015, 3:52pm

How did this work out for you?

mattford63 · March 3, 2015, 5:10pm

Hi,

It worked out well

I submitted a patch to the docs and got some dependencies (the python
mysql drivers) installed in the main docker image.

See here:

github.com

docker/docker-registry/blob/master/ADVANCED.md#high-availability-and-scaling

# Docker-Registry advanced use



## "extras"

The registry supports additional features (that require additional dependencies) that you may require at install time.

### Installation

If you are using the official registry container, you don't need to do anything, as all extras are installed by default.

If you are using pip, you have to explicitly request the extra you want, using pip extra syntax:

`pip install docker-registry[someextra]`

You can request several different extras at the same time by specifying a coma separated list, eg:

`pip install docker-registry[someextra,anotherextra]`

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Hope that helps,

Matt

akerekes · July 24, 2015, 3:56pm

Anyone has experience with scaling V2 registry in similar setup (using S3 backend)?

amurthy · March 10, 2016, 7:50am

Hi @akerekes, @mattford63

I am trying to make a similar setup (Two registry v2.3.1 containers both pointing to the same S3 backend) work, but when I try to pull an image on the second registry - with an image previously pushed by the first registry to S3 - I get an error specifying that the image could not be found.

Please can you share your other_args/DOCKER_OPTS and also how are you tagging the image during push/pull to S3?

Thanks
Aravind

cirocosta · April 26, 2017, 5:37pm

By the way, would it make sense to instead of using S3, use docker registry with a shared filesystem like EFS? Thanks!