'Proxy Cache' without '<harbor_server_name>/<proxy_project_name>' prefix?

[rogerfydp]

We are currently using [distribution](https://github.com/distribution/distribution) to cache Docker images from external repositories. In our setup, distribution is deployed on 10.0.0.50:5000. To use this setup in our Docker environments, we modify the Docker daemon configuration as follows:

"insecure-registries": [
    "http://10.0.0.50:5000"
],
"registry-mirrors": [
    "http://10.0.0.50:5000"
]

This setup works perfectly for us because we can continue referencing images in our docker-compose files or equivalent with the original Docker Hub image names, without requiring any prefixes.

For example:

services:
  app:
    image: nginx:latest

Now, we are considering migrating entirely to Harbor. However, based on the [Harbor documentation](https://goharbor.io/docs/2.1.0/administration/configure-proxy-cache/), it states:

To start using the proxy cache, configure your Docker pull commands or pod manifests to reference the proxy cache project by adding <harbor_servername>/<proxy_project_name>/ as a prefix to the image tag. For example:

docker pull <harbor_server_name>/<proxy_project_name>/goharbor/harbor-core:dev

While this approach works, it requires us to modify all docker-compose files or equivalent to include the <harbor_server_name>/<proxy_project_name>/ prefix, as shown:

services:
  app:
    image: <harbor_server_name>/<proxy_project_name>/nginx:latest

This introduces additional complexity for us.

Question:
Is there a recommended way in Harbor to achieve the same simple setup as we currently have with distribution, where we can continue referencing images without prefixes (e.g., just nginx:latest) while using Harbor's proxy cache functionality?

If not, is this feature planned or possible with custom configuration?

[ianseyer]

If I am understanding this correctly, we would like the same feature.

for example, if we have an upstream proxied registry that contains repository a, it would be nice to be able to pull the image located at a/b/c:latest via this proxy project by hitting harbor.com/a/b/c:latest rather than harbor.com/a/a/b/c:latest

EDIT: upon re-reading your issue, I do not believe this is possbile: the registry is a part of the tag. The docker client does not support changing the default registry from dockerhub.

[stonezdj]

Proxy cache in Harbor differs from registry-mirrors in distribution, do you have many applications run with docker-compose?

[reasonerjt]

EDIT: upon re-reading your issue, I do not believe this is possbile: the registry is a part of the tag. The docker client does not support changing the default registry from dockerhub.

I think this is correct, it won't be possible without changing the code at client-side.

[Vad1mo]

duplicate of #21342