Cached Nix Builds in GitHub Actions

This example demonstrates how to run Nix builds in GitHub Actions with Namespace.

Namespace dramatically speeds up the build performance by offering:

• higher performance per runner core
• flexible runner shapes (vCPU, RAM)
• local, high-performance Cache Volumes

In the example, we configure the Namespace runner with the following block:

    runs-on:
      - nscloud-ubuntu-22.04-amd64-4x16-with-cache
      - nscloud-cache-size-60gb
      - nscloud-cache-tag-cache-nix

Given this configuration, our workflow will run on a machine with 4 vCPU and 16 GB of RAM. Also, we mount a local, high-performance cache with 60 GB size at mount point /cache.

Next, we bind mount /nix to /cache/nix so that Nix artifacts are fully cached between runs.

Finally, we build netperf with Nix.