Initial scaffolding and layout

Set up the modules of the flake. At this time, the flake is split into
modules and machines. Considering that additional top-level sections --
such as packages and shells -- will also be added, it might make sense
to keep all nix related things in one top-level directory, alongside the
flake.nix file.

This is all under the assumption that later amendments to the project
will introduce other tech, such as terraform.

3 files changed, 104 insertions, 0 deletions

diff --git a/modules/xnet/monitoring/default.nix b/modules/xnet/monitoring/default.nix
new file mode 100644
index 0000000..87ae724
--- /dev/null
+++ b/modules/xnet/monitoring/default.nix
@@ -0,0 +1,38 @@
+{ config, ... }:
+let
+  inherit (config.networking) hostName;
+  inherit (config.services.prometheus) exporters;
+in
+{
+  imports = [ ./grafana.nix ./prometheus.nix ];
+
+  exporters = {
+    node = {
+      enable = true;
+      enabledCollectors = [ "processes" "systemd" ];
+    };
+
+    systemd = {
+      enable = true;
+      extraFlags = [
+        "--systemd.collector.enable-ip-accounting"
+        "--systemd.collector.enable-restart-count"
+      ];
+    };
+  };
+
+  services.prometheus.scrapeConfigs = [
+    {
+      job_name = "node";
+      static_configs = [{
+        targets = [ "${hostName}:${toString exporters.node.port}" ];
+      }];
+    }
+    {
+      job_name = "systemd";
+      static_configs = [{
+        targets = [ "${hostName}:${toString exporters.systemd.port}" ];
+      }];
+    }
+  ];
+}
diff --git a/modules/xnet/monitoring/grafana.nix b/modules/xnet/monitoring/grafana.nix
new file mode 100644
index 0000000..6a37ce1
--- /dev/null
+++ b/modules/xnet/monitoring/grafana.nix
@@ -0,0 +1,51 @@
+{ config, pkgs, ... }: {
+  services.grafana.provision = {
+    enable = true;
+    datasources.settings.datasources = [{
+      name = "Prometheus";
+      type = "prometheus";
+      url = "http://localhost:9090";
+      access = "proxy";
+      editable = false;
+    }];
+
+    dashboards.settings.providers = [{
+      name = "Fetched Dashboards";
+      options.path = "/etc/grafana/dashboards";
+    }];
+  };
+
+  environment.etc = {
+    "grafana/dashboards/node-exporter.json" = {
+      user = "grafana";
+      group = "grafana";
+      source = pkgs.fetchurl {
+        url = "https://grafana.com/api/dashboards/1860/revisions/37/download";
+        hash = "sha256-1DE1aaanRHHeCOMWDGdOS1wBXxOF84UXAjJzT5Ek6mM=";
+      };
+    };
+  };
+
+  services.grafana = {
+    enable = true;
+    settings.server = {
+      domain = "grafana.web.4kb.net";
+      protocol = "socket";
+    };
+    settings."auth.anonymous" = {
+      enabled = true;
+      org_role = "Admin";
+    };
+  };
+
+  users.groups.grafana.members = [ "nginx" ];
+  systemd.services.nginx.serviceConfig.ProtectHome = false;
+
+  services.nginx.virtualHosts."${config.services.grafana.settings.server.domain}" = {
+    useACMEHost = "4kb.net";
+    addSSL = true;
+    locations."/" = {
+      proxyPass = "http://unix:/${toString config.services.grafana.settings.server.socket}";
+    };
+  };
+}
diff --git a/modules/xnet/monitoring/prometheus.nix b/modules/xnet/monitoring/prometheus.nix
new file mode 100644
index 0000000..e32e078
--- /dev/null
+++ b/modules/xnet/monitoring/prometheus.nix
@@ -0,0 +1,15 @@
+{ config, ... }: {
+  services.prometheus = {
+    enable = true;
+    globalConfig.scrape_interval = "1m";
+    # scrapeConfigs = [{
+    #   job_name = "node";
+    #   relabel_configs = [{
+    #     source_labels = [ "__address__" ];
+    #     regex = "(.*):[0-9]+";
+    #     target_label = "instance";
+    #     replacement = "$1";
+    #   }];
+    # }];
+  };
+}