How to use Testcontainers Cloud with internal Docker registries?

Instructions for users who need to pull images from a ‘private’ registry that is not accessible from the public internet. Docker Hub, Amazon ECR, GCR, etc users *do not* need to use this feature, as these registries are exposed to the public internet

This feature requires version v1.2.0+ of the Testcontainers Cloud Desktop/agent application. 

Testcontainers Cloud Desktop usage:

Set per-user configuration in the ~/.testcontainers.properties file:

cloud.private_registry.proxy.url = https://private.registry.example.com:8999

enables images such as [private.registry.example.com:8999/prefix/name](<http://private.registry.example.com:8999/prefix/name>) to be pulled.

cloud.private_registry.proxy.allowed_image_name_globs = *,*/*

or

cloud.private_registry.proxy.allowed_image_name_globs = somepath/*,otherpath/namedimage

comma separated list of globs for images allow-listed for pulls (*,*/* means all). We recommend keeping the allow-list as small as possible.

Updates will be loaded on startup so you need to Restart Testcontainers Cloud application

agent CLI usage:

Add flags to the CLI invocation:

--private-registry-url=https://private.registry.example.com:8999

enables images such as [private.registry.example.com:8999/prefix/name](<http://private.registry.example.com:8999/prefix/name>) to be pulled.

--private-registry-allowed-image-name-globs=*,*/* 

or

--private-registry-allowed-image-name-globs=somepath/*,otherpath/namedimage

comma separated list of globs for images allow-listed for pulls (*,*/* means all). We recommend keeping the allow-list as small as possible.

Current limitations:

• At present, only a single private registry can be allow-listed for proxying.
• Image pull is supported, but push will be prevented.
• Proxying must be configured on a per-machine basis, but we expect this to later be configurable organisation-wide
• Credentials/tokens for all public/private docker registries are visible to the Testcontainers library and Testcontainers Cloud (data is proxied but not stored).
• Images pulled from private registries are cached within users’ Testcontainers Cloud VM, which is deleted automatically after being idle for approximately 30 minutes.