om health

The om health command checks the health of your Nix install. Furthermore, individual projects can configure their own health checks in their flake.nix. For example, the nammayatri project checks that the cachix cache is in use.

Checks performed

Note that some checks are considered non-essential. For eg., the disk space check looks for 1TB+ disk space, but if the user is on a laptop with 256GB SSD, the check will report a warning instead of failing. This can also be configured in per-project basis from flake.nix (see below).

Usage

om health

To run use the health check configuration specified in a project flake, pass that flake as an argument. For eg., to run halth checks defined from the nammayatri project, run:

# The argument can be any flake URL (including a local path)
om health github:nammayatri/nammayatri

Per-project configuration

To add project specific health checks or configure health checks, add the following to your om.yaml:

health:
  default:
    caches:
      required:
        - "https://ourproject.cachix.org"

To see all available configuration options, run om health --dump-schema. This will dump the schema of the configuration in JSON format. Convert that to YAML to see what can be added under the om.health.default key of your om.yaml.

$ om health --dump-schema | nix run nixpkgs#yq-go -- -P

This will output:

flake-enabled: {}
nix-version:
  min-required: 2.16.0
rosetta:
  enable: true
  required: true
max-jobs: {}
trusted-users: {}
caches:
  required:
    - https://cache.nixos.org/
direnv:
  enable: true
  required: false
shell:
  enable: true
  required: false

Adding devShell check

You can automatically run om health as part of direnv invocation; see om develop for details.