Alloy configuration updates (#21)

* feat: switch to nixpkgs alloy package and service, some improvements to alloy ergonomics

* feat: nix flake update

* fix: update alloy-forwarder nix config for new module

flake.nix

@@ -7,9 +7,6 @@
 
  srvos.url = "github:nix-community/srvos";
  srvos.inputs.nixpkgs.follows = "nixpkgs";
-
- pkgs-nix.url = "github:ALT-F4-LLC/pkgs.nix";
- pkgs-nix.inputs.nixpkgs.follows = "nixpkgs";
  };
 
  outputs = inputs @ {flake-parts, ...}:

modules/mixins/alloy-forwarder/config.alloy

@@ -20,20 +20,29 @@ prometheus.receive_http "forward" {
  ]
 }
 
-prometheus.scrape "linux_node" {
- targets = prometheus.exporter.unix.node.targets
- forward_to = [ grafana_cloud.stack.receivers.metrics ]
+// Set instance label to the hostname
+prometheus.relabel "instance" {
+ forward_to = [grafana_cloud.stack.receivers.metrics]
+ rule {
+ target_label = "instance"
+ replacement = local.file.hostname.content
+ }
 }
 
 prometheus.exporter.unix "node" {
 }
 
+prometheus.scrape "linux_node" {
+ targets = prometheus.exporter.unix.node.targets
+ forward_to = [prometheus.relabel.instance.receiver]
+}
+
 prometheus.exporter.self "agent" {
 }
 
 prometheus.scrape "agent" {
  targets = prometheus.exporter.self.agent.targets
- forward_to = [ grafana_cloud.stack.receivers.metrics ]
+ forward_to = [prometheus.relabel.instance.receiver]
 }
 
 loki.source.api "receive" {
@@ -46,45 +55,21 @@ loki.source.api "receive" {
  ]
 }
 
-loki.relabel "journal" {
- forward_to = []
-
- rule {
- source_labels = ["__journal__systemd_unit"]
- target_label = "unit"
- }
- rule {
- source_labels = ["__journal__boot_id"]
- target_label = "boot_id"
- }
- rule {
- source_labels = ["__journal__transport"]
- target_label = "transport"
- }
- rule {
- source_labels = ["__journal_priority_keyword"]
- target_label = "level"
- }
- rule {
- source_labels = ["__journal__hostname"]
- target_label = "instance"
- }
-}
-
 loki.source.journal "read" {
  forward_to = [
  grafana_cloud.stack.receivers.logs,
  ]
- relabel_rules = loki.relabel.journal.rules
+ relabel_rules = concat(
+ loki.relabel.journal.rules,
+ loki.relabel.instance.rules,
+ )
  labels = {
  "job" = "integrations/node_exporter",
  }
 }
 
 otelcol.exporter.prometheus "to_prometheus" {
- forward_to = [
- grafana_cloud.stack.receivers.metrics,
- ]
+ forward_to = [grafana_cloud.stack.receivers.metrics]
 }
 
 otelcol.exporter.loki "to_loki" {

modules/mixins/alloy-forwarder/default.nix

@@ -15,12 +15,9 @@
  4317 # OTLP/gRPC
  ];
 
- services.alloy = {
- extraArgs = "--stability.level public-preview";
-
- environmentFiles = [ "/run/keys/grafana-cloud" ];
- extraEnvironment = {
- GRAFANA_CLOUD_STACK = "altf4llc";
- };
+ services.alloy.extraFlags = ["--stability.level=public-preview"];
+ systemd.services.alloy.serviceConfig.EnvironmentFile = [ "/run/keys/grafana-cloud" ];
+ systemd.services.alloy.environment = {
+ GRAFANA_CLOUD_STACK = "altf4llc";
  };
 }

modules/mixins/alloy/base.alloy

@@ -0,0 +1,56 @@
+// Grab hostname from /etc instead of environment variables
+local.file "hostname" {
+ filename = "/etc/hostname"
+}
+
+// Set hostname from /etc
+loki.relabel "instance" {
+ forward_to = []
+
+ rule {
+ target_label = "instance"
+ replacement = local.file.hostname.content
+ }
+}
+
+// Loki journal relabeller
+loki.relabel "journal" {
+ forward_to = []
+
+ rule {
+ source_labels = ["__journal__systemd_unit"]
+ target_label = "unit"
+ }
+
+ rule {
+ source_labels = ["__journal__boot_id"]
+ target_label = "boot_id"
+ }
+
+ rule {
+ source_labels = ["__journal__transport"]
+ target_label = "transport"
+ }
+
+ rule {
+ source_labels = ["__journal_priority_keyword"]
+ target_label = "level"
+ }
+
+ rule {
+ source_labels = ["__journal_container_name"]
+ target_label = "container_name"
+ }
+
+ rule {
+ source_labels = ["__journal_image_name"]
+ target_label = "container_image"
+ }
+
+ rule {
+ source_labels = ["__journal_container_id"]
+ target_label = "container_id"
+ }
+}
+
+// vim:ft=hcl

modules/mixins/alloy/config.alloy

@@ -64,7 +64,7 @@ prometheus.relabel "instance" {
  forward_to = [otelcol.receiver.prometheus.default.receiver]
  rule {
  target_label = "instance"
- replacement = env("HOSTNAME")
+ replacement = local.file.hostname.content
  }
 }
 

modules/mixins/alloy/default.nix

@@ -1,18 +1,15 @@
-{ pkgs-nix, pkgs, ... }: {
- imports = [ pkgs-nix.nixosModules.alloy ];
-
+{ ... }: {
  environment.etc."alloy/config.alloy" = {
  source = ./config.alloy;
  mode = "0440";
  user = "root";
  };
 
- services.alloy = {
- enable = true;
- package = pkgs-nix.packages.${pkgs.system}.alloy;
- openFirewall = true;
- configPath = "/etc/alloy";
- group = "root";
+ environment.etc."alloy/base.alloy" = {
+ source = ./base.alloy;
+ mode = "0440";
  user = "root";
  };
+
+ services.alloy.enable = true;
 }