Public Registry Proxy Cache✯
The proxyfied registry proxies several public registries. In practice, you retrieve an image from a public registry through registry.isima.fr, which downloads and then caches it.
What are the benefits?
- Faster: Frequently used images are served from the local cache within the establishment's network.
- No rate limiting: You bypass download quotas imposed by some public registries (notably Docker Hub's rate limits).
- Transparent: No special configuration required; simply prefix the image name.
Available Proxyfied Registries✯
| Public Registry | Prefix to use on registry.isima.fr |
|---|---|
| Docker Hub | registry.isima.fr/dh/<image>:<tag> |
| Docker Hardened Images | registry.isima.fr/dhi/<image>:<tag> |
| GitHub Container Registry | registry.isima.fr/ghcr/<image>:<tag> |
| Google Container Registry | registry.isima.fr/gcr/<image>:<tag> |
| Quay | registry.isima.fr/quay.io/<image>:<tag> |
| Linuxserver.io | registry.isima.fr/lscr/<image>:<tag> |
Retrieving an Image via the Proxy✯
Simply prefix the image name with registry.isima.fr/<prefix>/.
Official Docker Hub images are located in the library namespace. A user image retains its namespace <user>/<image>.
# nginx (official image: hub.docker.com/_/nginx)
docker pull registry.isima.fr/dh/library/nginx:latest
# a user image (hub.docker.com/r/bitnami/postgresql)
docker pull registry.isima.fr/dh/bitnami/postgresql:16
# ghcr.io/home-assistant/home-assistant:stable
docker pull registry.isima.fr/ghcr/home-assistant/home-assistant:stable
# quay.io/prometheus/prometheus:latest
docker pull registry.isima.fr/quay.io/prometheus/prometheus:latest
# gcr.io/distroless/static-debian12
docker pull registry.isima.fr/gcr/distroless/static-debian12
# lscr.io/linuxserver/nextcloud:latest
docker pull registry.isima.fr/lscr/linuxserver/nextcloud:latest
In a Dockerfile
You can also point your FROM instructions to the proxy to speed up your builds:
FROM registry.isima.fr/dh/library/python:3.12-slim
How Does the Cache Work?✯
- First
pull: The image is downloaded from the public registry, served, and then cached. - Subsequent
pulls: The registry checks with the source if the image has changed. If unchanged, the cached version is served directly. - Source unreachable: If the public registry is unavailable, the cached version remains accessible.
Retention Policy
Images from a proxy cache project are automatically purged from the cache after a period of inactivity (default: 7 days without use). A purged image will simply be re-downloaded on the next pull.
Authentication
Depending on the configuration, access to proxy cache projects may require authentication (docker login registry.isima.fr). Be sure to do this, especially in your GitLab pipelines.