Docker Hub is a repository for Docker images — a place to store the Linux containers. It’s a single site (in a logical, not physical, sense) run by Docker Inc. It was conceived of as a library — “a Wikipedia, if you will, of the images themselves,” says Scott Johnston, Docker’s senior vice president of product.
But Docker has been pleased to see a rise in another use case — collaborative application development. The Hub’s creators had anticipated this but have been pleasantly surprised at how fervently its caught on.
Applications are often built by teams rather than by individuals, and Docker Hub gives them a place to leave containers for one another to use; they can also use scripts to automate the building of a pipeline of containers, Johnston says. It’s as though the Hub has become a platform for automating workflows.
Docker Hub now boasts more than 300,000 accounts from 17,000 organizations. That’s rapid growth, considering the hub didn’t exist 16 months ago, and that forced Docker to rethink the Hub’s architecture. “We’ve completely rebuilt the back-end stack, and we completely rebuilt the front-end stack,” Johnston says.
The “rebuilding” of the stacks is actually an ongoing process — by the DevOps principle of continuous integration, it never really ends — but the changes Johnston refers to are specific to nine months of work that ended during the summer.
Docker also corralled Docker Hub to less than five service providers. “It used to be spread across 20 different service providers,” Johnston says, adding that the new setup means fewer hops across the WAN.
All the changes have improved download speeds by a factor of 2.5 and interface response times by a factor of 1.9, Docker claims.
Docker also offers a private alternative to the Hub, called the Docker Trusted Registry (DTR). Formerly called Docker Hub Enterprise and launched to general availability in June, DTR is downloadable from Docker Hub and sets up a mini-Docker Hub that can sit behind an organization’s firewall.
Yesterday, Docker announced a version of DTR for Amazon Web Services (AWS), allowing customers to essentially rent an AWS-hosted version of DTR.