{ # enable the node exporter on all nixos hosts # https://github.com/NixOS/nixpkgs/blob/nixos-25.11/nixos/modules/services/monitoring/prometheus/exporters/node.nix services.prometheus.exporters.node = { enable = true; listenAddress = "0.0.0.0"; port = 9100; # There're already a lot of collectors enabled by default # https://github.com/prometheus/node_exporter?tab=readme-ov-file#enabled-by-default enabledCollectors = [ "systemd" "logind" ]; # use either enabledCollectors or disabledCollectors # disabledCollectors = []; extraFlags = [ # Exclude pseudo/ephemeral FS: # - /proc, /sys: kernel pseudo-FS, always size 0 # - /dev: tmpfs/devices, not meaningful for disk usage # Exclude system/runtime tmp dirs: # - /run/credentials/... → systemd service secrets (strict perms) # - /run/user/... → per-user tmpfs (0700, IPC sockets, not storage) # Exclude container/runtime mounts: # - /var/lib/docker/, /var/lib/containers/ and /var/lib/kubelet/ → too much overlay/tmpfs mounts, # often EACCES (strict perms, namespaces) → false alerts # Exclude user bind mounts: # - /home/ryan/.+ → bind-mounted from /persistent (NixOS tmpfs-root setup), # monitoring /persistent is sufficient # Note: ^(/|/persistent/) prefix ensures both root-level and # /persistent-prefixed paths (used in NixOS's tmpfs-as-root setup) are excluded. "--collector.filesystem.mount-points-exclude=^(/|/persistent/)(dev|proc|sys|run/credentials/.+|run/user/.+|var/lib/docker/.+|var/lib/containers/.+|var/lib/kubelet/.+|home/ryan/.+)($|/)" ]; }; }