How to Debug Docker Registries Like a Pro

Debugging Docker Registries

Everyone is talking about Docker registries, so let’s take a few minutes to talk about how to debug them. Here are a few tools in my toolbox that I can recommend for troubleshooting Docker registries.

Docker in Docker

Also referred to as “dind”, this official project from Docker offers Docker images for pretty much every Docker version out there. Set up (and destroy) any docker version, literally, in seconds — super useful for testing version-specific behavior.

Charles Proxy

One of the best troubleshooting-oriented HTTP proxies out there. From inspecting HTTP headers and request/response payload, to setting up request breakpoints and terminating requests abruptly (and watching things collapse), there isn’t a lot more one can ask from such a tool!


Master of sockets (“socat” means “socket cat”, where “cat” is the unix ‘cat’ command – Get It?). Nothing can hide from Socat – dig out the nitty gritty from virtually any type of socket you can think of. With Docker, we use Socat to debug the client<>daemon interaction.


A lightweight (6Mb), non-production reverse-proxy written in Go, tailored to work with JFrog Artifactory. Groxy provides an easy gateway to the Artifactory Docker registry APIs. Pull the docker image, use the JSON-based configuration file to point to your Artifactory URL, port and docker repository names, and you’re up and running. Nginx and Apache are not invited to this party.

Want to see these in action? Take a look at some of my actual walkthroughs that demonstrate exactly how you can easily implement these powerful and readily available tools.

Visit the JFrog Knowledge Base to find the answers to your questions directly from our experts.