From 6b028bcf358fbba1f48db6e380d3348e8bd5210a Mon Sep 17 00:00:00 2001
From: Martin Milata <martin@martinmilata.cz>
Date: Sun, 31 May 2020 22:47:10 +0200
Subject: [PATCH] nixos/prometheus-bitcoin-exporter: init

---
 .../monitoring/prometheus/exporters.nix       |  1 +
 .../prometheus/exporters/bitcoin.nix          | 82 +++++++++++++++++++
 nixos/tests/prometheus-exporters.nix          | 18 ++++
 3 files changed, 101 insertions(+)
 create mode 100644 nixos/modules/services/monitoring/prometheus/exporters/bitcoin.nix

diff --git a/nixos/modules/services/monitoring/prometheus/exporters.nix b/nixos/modules/services/monitoring/prometheus/exporters.nix
index 5f6a86afdcd..7dc7630ac0a 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters.nix
@@ -25,6 +25,7 @@ let
     "artifactory"
     "bind"
     "bird"
+    "bitcoin"
     "blackbox"
     "collectd"
     "dnsmasq"
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/bitcoin.nix b/nixos/modules/services/monitoring/prometheus/exporters/bitcoin.nix
new file mode 100644
index 00000000000..43721f70b49
--- /dev/null
+++ b/nixos/modules/services/monitoring/prometheus/exporters/bitcoin.nix
@@ -0,0 +1,82 @@
+{ config, lib, pkgs, options }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.bitcoin;
+in
+{
+  port = 9332;
+  extraOpts = {
+    rpcUser = mkOption {
+      type = types.str;
+      default = "bitcoinrpc";
+      description = ''
+        RPC user name.
+      '';
+    };
+
+    rpcPasswordFile = mkOption {
+      type = types.path;
+      description = ''
+        File containing RPC password.
+      '';
+    };
+
+    rpcScheme = mkOption {
+      type = types.enum [ "http" "https" ];
+      default = "http";
+      description = ''
+        Whether to connect to bitcoind over http or https.
+      '';
+    };
+
+    rpcHost = mkOption {
+      type = types.str;
+      default = "localhost";
+      description = ''
+        RPC host.
+      '';
+    };
+
+    rpcPort = mkOption {
+      type = types.port;
+      default = 8332;
+      description = ''
+        RPC port number.
+      '';
+    };
+
+    refreshSeconds = mkOption {
+      type = types.ints.unsigned;
+      default = 300;
+      description = ''
+        How often to ask bitcoind for metrics.
+      '';
+    };
+
+    extraEnv = mkOption {
+      type = types.attrsOf types.str;
+      default = {};
+      description = ''
+        Extra environment variables for the exporter.
+      '';
+    };
+  };
+  serviceOpts = {
+    script = ''
+      export BITCOIN_RPC_PASSWORD=$(cat ${cfg.rpcPasswordFile})
+      exec ${pkgs.prometheus-bitcoin-exporter}/bin/bitcoind-monitor.py
+    '';
+
+    environment = {
+      BITCOIN_RPC_USER = cfg.rpcUser;
+      BITCOIN_RPC_SCHEME = cfg.rpcScheme;
+      BITCOIN_RPC_HOST = cfg.rpcHost;
+      BITCOIN_RPC_PORT = toString cfg.rpcPort;
+      METRICS_ADDR = cfg.listenAddress;
+      METRICS_PORT = toString cfg.port;
+      REFRESH_SECONDS = toString cfg.refreshSeconds;
+    } // cfg.extraEnv;
+  };
+}
diff --git a/nixos/tests/prometheus-exporters.nix b/nixos/tests/prometheus-exporters.nix
index c32cd341e5e..b921090f527 100644
--- a/nixos/tests/prometheus-exporters.nix
+++ b/nixos/tests/prometheus-exporters.nix
@@ -136,6 +136,24 @@ let
       '';
     };
 
+    bitcoin = {
+      exporterConfig = {
+        enable = true;
+        rpcUser = "bitcoinrpc";
+        rpcPasswordFile = pkgs.writeText "password" "hunter2";
+      };
+      metricProvider = {
+        services.bitcoind.default.enable = true;
+        services.bitcoind.default.rpc.users.bitcoinrpc.passwordHMAC = "e8fe33f797e698ac258c16c8d7aadfbe$872bdb8f4d787367c26bcfd75e6c23c4f19d44a69f5d1ad329e5adf3f82710f7";
+      };
+      exporterTest = ''
+        wait_for_unit("prometheus-bitcoin-exporter.service")
+        wait_for_unit("bitcoind-default.service")
+        wait_for_open_port(9332)
+        succeed("curl -sSf http://localhost:9332/metrics | grep -q '^bitcoin_blocks '")
+      '';
+    };
+
     blackbox = {
       exporterConfig = {
         enable = true;