Harmonia v2.0.0 release

[Mic92]

Harmonia is a binary cache that serves /nix/store over HTTP to other machines.

Harmonia now includes built-in zstd compression for content. If you previously had the nginx zstd module configured, you can safely remove it. Nix will automatically utilize compression when it is available.

This release eliminates libnix dependencies from Harmonia, meaning there is no longer any “unsafe” code in its source tree, except for a single call to libsodium for signing. Instead, Harmonia now uses the nix-daemon protocol whenever it needs to interact with Nix.

[TheDragon]

Is there any potential downsides to running this alongside ncps on the same machine with the same nix-store?

Just curious as they do (if I understand correctly) seem to compliment one another.

If so, would I need to make any particular adjustments to the recommended configuration in Harmonia’s README?

A link, just in case you didn’t recognize the name

Announcing ncps: A Nix Cache Proxy Server for Faster Builds!

Hey Nix community, I’m excited to announce ncps, a new proxy server designed to speed up your Nix dependency retrieval and build times, especially in environments with multiple machines. ncps acts as a local binary cache on your network, fetching store paths from upstream caches (like cache.nixos.org) and storing them locally. This means: Reduced bandwidth usage: Each dependency is pulled only once onto the cache, and then all machines on your network can use it, saving on internet costs and…

[Mic92]

I think they can be combined, but I never tried that. Only caveat might be that at least when I checked ncps supports less features i.e no logs or nar listing, so you might loose that.

[numinit]

In my experience, they complement each other very nicely. In fact, the NixOS tests for NCPS use Harmonia to test substitution. (I learned this while working on tests for substitution over 802.11s mesh).

[TheDragon]

Thanks @Mic92 and @numinit - really appreciate the feedback… I’ll give it a shot!