nixos: add module, test, package and patch

.gitignore

@@ -3,4 +3,5 @@ debian/files
 debian/prometheus-mgit-exporter.debhelper.log
 debian/prometheus-mgit-exporter.substvars
 debian/prometheus-mgit-exporter/
-prometheus-mgit-exporter
+prometheus-mgit-exporter
+result*

default.nix

@@ -0,0 +1,21 @@
+{ buildGoModule
+, lib
+}:
+
+buildGoModule rec {
+  pname = "prometheus-mgit-exporter";
+  # get version from BUILD.bazel
+  version = with builtins; elemAt (match ".*version = \"([0-9.]*)\".*" (readFile ./BUILD.bazel)) 0;
+
+  src = ./.;
+
+  vendorHash = "sha256-q2e6Q8MbnpOguUNxTumpm3tGbBNes3ada9ma1agcTvs=";
+
+  meta = with lib; {
+    description = "A collection of useful monitoring for Prometheus by mgIT GmbH.";
+    homepage = "https://github.com/mgit-at/prometheus-mgit-exporter";
+    license = licenses.apsl20;
+    maintainers = with maintainers; [ mkg20001 ];
+    mainProgram = "prometheus-mgit-exporter";
+  };
+}

flake.nix

@@ -0,0 +1,56 @@
+{
+  description = "A collection of useful monitoring for Prometheus by mgIT GmbH.";
+
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  inputs.patches4nixpkgs.url = "github:mgit-at/patches4nixpkgs/master";
+
+  outputs = { self, patches4nixpkgs, ... }@inputs:
+    let
+      patchPkgs = patches4nixpkgs.patch inputs.nixpkgs [ self ];
+      nixpkgs = patches4nixpkgs.eval patchPkgs;
+
+      supportedSystems = [ "x86_64-linux" "aarch64-linux" ];
+      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+    in
+    {
+      overlays.default = final: prev: {
+        prometheus-mgit-exporter = prev.callPackage ./. {};
+      };
+
+      patches4nixpkgs = nixpkgs: [
+        [
+          (! builtins.pathExists "${nixpkgs}/nixos/modules/services/monitoring/prometheus/mk-downstream-exporter.nix")
+          ./nixos-prom-downstream.patch
+        ]
+      ];
+
+      packages = forAllSystems (system:
+        let
+          pkgs = (import nixpkgs {
+            inherit system;
+            overlays = [ self.overlays.default ];
+          });
+        in
+        {
+          inherit (pkgs) prometheus-mgit-exporter;
+          default = pkgs.prometheus-mgit-exporter;
+        }
+      );
+
+      nixosModules = {
+        prometheus-mgit-exporter = import ./module.nix;
+      };
+
+      checks = forAllSystems (system:
+        let
+          pkgs = (import nixpkgs {
+            inherit system;
+            overlays = [ self.overlays.default ];
+          });
+        in
+        {
+          prometheus-mgit-exporter = pkgs.testers.runNixOSTest (import ./test.nix);
+        }
+      );
+  };
+}

mgit-exporter.nix

@@ -0,0 +1,159 @@
+# nixpkgs/nixos/modules/services/prometheus/exporters/mgit.nix
+{ config, lib, pkgs, options, utils, ... }:
+
+with lib;
+
+let
+  # for convenience we define cfg here
+  cfg = config.services.prometheus.exporters.mgit;
+  json = pkgs.formats.json {};
+  configurationFile = json.generate "config.json" cfg;
+in
+{
+  port = 9328; # The mgit exporter listens on this port by default
+
+  # `extraOpts` is an attribute set which contains additional options
+  # (and optional overrides for default options).
+  # Note that this attribute is optional.
+  extraOpts = {
+    listen = mkOption {
+      default = ":${toString cfg.port}";
+      type = types.str;
+      description = "Listening address";
+    };
+
+    certFile = {
+      enable = mkEnableOption "certificate file watching";
+      globs = mkOption {
+        default = [];
+        type = types.listOf types.str;
+        description = "List of globs";
+      };
+      exclude_system = mkOption {
+        type = types.bool;
+        description = "Exclude system certificates";
+        default = false;
+      };
+    };
+
+    mceLog = {
+      enable = mkEnableOption "MCE log";
+      path = mkOption {
+        default = "";
+        type = types.str;
+        description = "Path to MCE log";
+      };
+    };
+
+    ptHeartbeat = {
+      enable = mkEnableOption "PT heartbeat";
+      database = mkOption {
+        default = "";
+        type = types.str;
+        description = "Database for PT heartbeat";
+      };
+      table = mkOption {
+        default = "";
+        type = types.str;
+        description = "Table for PT heartbeat";
+      };
+      defaultsFile = mkOption {
+        default = "";
+        type = types.str;
+        description = "Defaults file for PT heartbeat";
+      };
+      masterId = mkOption {
+        default = 0;
+        type = types.int;
+        description = "Master ID for PT heartbeat";
+      };
+    };
+
+    fsTab = {
+      enable = mkEnableOption "fsTab";
+    };
+
+    binLog = {
+      enable = mkEnableOption "binLog";
+      path = mkOption {
+        default = "";
+        type = types.str;
+        description = "Path to binLog";
+      };
+    };
+
+    rasDaemon = {
+      enable = mkEnableOption "rasDaemon";
+      path = mkOption {
+        default = "";
+        type = types.str;
+        description = "Path to rasDaemon";
+      };
+    };
+
+    elk = {
+      enable = mkEnableOption "elk";
+      duration = mkOption {
+        default = "";
+        type = types.str;
+        description = "Duration for elk";
+      };
+      node = mkOption {
+        default = "default_node";
+        type = types.str;
+        description = "Node for elk";
+      };
+    };
+
+    exec = {
+      enable = mkEnableOption "exec";
+      scripts = mkOption {
+        default = {};
+        type = types.attrsOf (types.submodule ({ ... }: {
+          options = {
+            command = mkOption {
+              type = types.listOf types.str;
+              description = "Command";
+            };
+
+            dir = mkOption {
+              type = types.str;
+              description = "Working directory";
+              default = "";
+            };
+
+            timeout = mkOption {
+              type = types.str;
+              description = "Timeout";
+              default = "";
+            };
+          };
+        }));
+        description = "Scripts for exec";
+      };
+    };
+  };
+
+  # `serviceOpts` is an attribute set which contains configuration
+  # for the exporter's systemd service. One of
+  # `serviceOpts.script` and `serviceOpts.serviceConfig.ExecStart`
+  # has to be specified here. This will be merged with the default
+  # service configuration.
+  # Note that by default 'DynamicUser' is 'true'.
+  serviceOpts = {
+    unitConfig = {
+      Description = "mgIT exporter for Prometheus";
+      Documentation = "https://prometheus.io/docs/introduction/overview/";
+    };
+    serviceConfig = {
+      MemoryMax = "1G";
+      Restart = "on-failure";
+      RestartSec = 1;
+      DynamicUser = false;
+      ExecStart = utils.escapeSystemdExecArgs [
+        (getExe pkgs.prometheus-mgit-exporter)
+        "-config" (toString configurationFile)
+      ];
+    };
+  };
+}

module.nix

@@ -0,0 +1,8 @@
+{ modulesPath, ... }: {
+  imports = [
+    (import "${modulesPath}/services/monitoring/prometheus/mk-downstream-exporter.nix" {
+      name = "mgit";
+      file = ./mgit-exporter.nix;
+    })
+  ];
+}