Docker Hub and JFrog announced a partnership that would enable JFrog Artifactory users to avoid Docker Hub image pull rate and retention limits.
Last year in August, Docker had announced rate limit policies for image pulls and an inactive image retention policy. In a subsequent announcement in November 2020, they stated the postponement of the latter. However, rate limits continued to apply at different tiers of paid Docker subscriptions. Docker Pro and Team users are free from the rate limits - "as long as the quantities are not excessive or abusive". Free Docker Hub logged-in users have a limit of 200 container image requests per 6 hours, whereas anonymous users have a limit of 100 pulls in the same period. These restrictions are not present for non-commercial open source projects that satisfy certain criteria.
JFrog's Artifactory is a repository for software artifacts, Helm charts and Docker images that can be self-hosted or used as a SaaS solution. The new partnership between JFrog and Docker Hub removes these restrictions for users who access Docker Hub via JFrog’s Artifactory. This applies to both free and paid JFrog subscriptions, according to their pricing page, as of this writing.
This development covers a couple of use cases in JFrog. One of them is using JFrog Artifactory as a pull-through cache for Docker Hub images. This is possible by configuring Docker Hub as a remote repository, thus reducing the number of pulls made to Docker Hub. Images stored in the cache are refreshed periodically. Another is using Artifactory itself as a container registry, where images are pulled from Docker Hub and stored locally. Images stored in an Artifactory registry are not subject to the retention limits in Docker Hub either - because they are local copies.
Users of registries hosted by cloud vendors can usually take advantage of local caching offered by the vendors. For example, Google Container Registry (GCR) "caches frequently-accessed public Docker Hub images" on mirror.gcr.io. Both GCR and Amazon’s Elastic Container Registry (ECR), another public registry announced last year, do have service quotas but they are high enough that normal usage is unlikely to reach them. The same applies to Azure Container Registry.
The partnership also includes dedicated channels to support mutual customers, according to the press release. It noted that this is the first step in possible future collaborations between the two companies.