m/hut/monitoring.nix

@@ -3,6 +3,7 @@
 {
   imports = [
     ../module/slurm-exporter.nix
+    ../module/meteocat-exporter.nix
     ./gpfs-probe.nix
     ./nix-daemon-exporter.nix
   ];
@@ -110,6 +111,7 @@
             "127.0.0.1:9341" # Slurm exporter
             "127.0.0.1:9966" # GPFS custom exporter
             "127.0.0.1:9999" # Nix-daemon custom exporter
+            "127.0.0.1:9929" # Meteocat custom exporter
             "127.0.0.1:${toString config.services.prometheus.exporters.blackbox.port}"
           ];
         }];

m/module/meteocat-exporter.nix

@@ -0,0 +1,17 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  systemd.services."prometheus-meteocat-exporter" = {
+    wantedBy = [ "multi-user.target" ];
+    after = [ "network.target" ];
+    serviceConfig = {
+      Restart = mkDefault "always";
+      PrivateTmp = mkDefault true;
+      WorkingDirectory = mkDefault "/tmp";
+      DynamicUser = mkDefault true;
+      ExecStart = "${pkgs.meteocat-exporter}/bin/meteocat-exporter";
+    };
+  };
+}

pkgs/meteocat-exporter/default.nix

@@ -0,0 +1,25 @@
+{ python3Packages, lib }:
+
+python3Packages.buildPythonApplication rec {
+  pname = "meteocat-exporter";
+  version = "1.0";
+
+  src = ./.;
+
+  doCheck = false;
+
+  build-system = with python3Packages; [
+    setuptools
+  ];
+
+  dependencies = with python3Packages; [
+    beautifulsoup4
+    lxml
+    prometheus-client
+  ];
+
+  meta = with lib; {
+    description = "MeteoCat Prometheus Exporter";
+    platforms = platforms.linux;
+  };
+}

pkgs/meteocat-exporter/meteocat-exporter

@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+
+import time
+from prometheus_client import start_http_server, Gauge
+from bs4 import BeautifulSoup
+from urllib import request
+
+# Configuration -------------------------------------------
+meteo_station = "X8" # Barcelona - Zona Universitària
+listening_port = 9929
+update_period = 60 * 5 # Each 5 min
+# ---------------------------------------------------------
+
+metric_tmin = Gauge('meteocat_temp_min', 'Min temperature')
+metric_tmax = Gauge('meteocat_temp_max', 'Max temperature')
+metric_tavg = Gauge('meteocat_temp_avg', 'Average temperature')
+metric_srad = Gauge('meteocat_solar_radiation', 'Solar radiation')
+
+def update(st):
+    url = 'https://www.meteo.cat/observacions/xema/dades?codi=' + st
+    response = request.urlopen(url)
+    data = response.read()
+    soup = BeautifulSoup(data, 'lxml')
+    table = soup.find("table", {"class" : "tblperiode"})
+    rows = table.find_all('tr')
+    row = rows[-1] # Take the last row
+    row_data = []
+    header = row.find('th')
+    header_text = header.text.strip()
+    row_data.append(header_text)
+    for col in row.find_all('td'):
+        row_data.append(col.text)
+    try:
+        # Sometimes it will return '(s/d)' and fail to parse
+        metric_tavg.set(float(row_data[1]))
+        metric_tmax.set(float(row_data[2]))
+        metric_tmin.set(float(row_data[3]))
+        metric_srad.set(float(row_data[10]))
+        #print("ok: temp_avg={}".format(float(row_data[1])))
+    except:
+        print("cannot parse row: {}".format(row))
+        metric_tavg.set(float("nan"))
+        metric_tmax.set(float("nan"))
+        metric_tmin.set(float("nan"))
+        metric_srad.set(float("nan"))
+
+if __name__ == '__main__':
+    start_http_server(port=listening_port, addr="localhost")
+    while True:
+        try:
+            update(meteo_station)
+        except:
+            print("update failed")
+        time.sleep(update_period)

pkgs/meteocat-exporter/setup.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python
+
+from setuptools import setup, find_packages
+
+setup(name='meteocat-exporter',
+      version='1.0',
+      # Modules to import from other scripts:
+      packages=find_packages(),
+      # Executables
+      scripts=["meteocat-exporter"],
+     )

pkgs/overlay.nix

@@ -54,4 +54,5 @@ final: prev:
   });
 
   prometheus-slurm-exporter = prev.callPackage ./slurm-exporter.nix { };
+  meteocat-exporter = prev.callPackage ./meteocat-exporter/default.nix { };
 }