frida-gum VS mirrord

LD_PRELOAD1, available as an environment variable, is a feature provided by dynamic linkers like ld.so that lets us load a shared library into a process before the process loads anything else. In our case, we use LD_PRELOAD to load mirrord-layer, which overrides libc functions with a custom implementation. By overriding file and socket functions, we can then transparently plug the process into the remote pod, having it read and write files and traffic remotely without changing a single line of code. Overriding these libc functions on different systems would have been a difficult task and this is where Frida-gum comes to save the day through its inline hooking interceptor.

So, you've been using mirrord to simplify your development process (if you haven’t, go here!). Naturally, you want the traffic from the app you're debugging to go through the cluster environment, so your app can communicate with its clustery pals. There is a problem though: your latest change adds some new columns to the database, and you don’t want to modify the database in the cluster and affect everyone else working on it. You do have a local instance of the database that you can modify, so your app can use that, but you still want it to talk to all the other components in the cluster. So what now? The new outgoing traffic filter feature is here to solve exactly this type of problem!

I had the pleasure of talking to Eyal @ CTO at Metalbear and the maintainer of Mirrord. I got some crazy insights.

If you want to take mirrord for a spin, check out the quick start guide. We’d love to hear about your experience or just general thoughts - chat us up on our Discord or open an issue or discussion on GitHub.

We're building an open-source tool called mirrord which lets you run a local process in the context of a pod in your cloud environment. We often get asked how mirrord is different from Telepresence and so we decided to write a short blog post about it, which we hope would be valuable to those interested in local Kubernetes development:

Hands-on tutorial of mirrord.dev with the creators and Rawkode!

if you are interested in k8s, iptables, hooking libc, asm etc https://github.com/metalbear-co/mirrord

I gave my first CNCF talk in Toronto yesterday, talking about https://github.com/metalbear-co/mirrord , how all the features work, and how it's engineered!