DataSources/DnsmasqSource.cpp

@@ -3,21 +3,33 @@
 //
 
 #include "DnsmasqSource.h"
+#include <exception>
 #include <sstream>
+#include <iostream>
 #include <ranges>
+#include <array>
+#include <algorithm>
+
+namespace views = std::ranges::views;
 
 DnsmasqSource::DnsmasqSource() {
+    _leases.open("/var/lib/misc/dnsmasq.leases");
+    if(_leases.fail()) {
+        throw std::runtime_error("failed to open leases file");
+    }
 }
 
 std::vector<prometheus::Labels> DnsmasqSource::readLeases() {
-    std::ifstream leases("/var/lib/misc/dnsmasq.leases");
+    _leases.clear();
+    _leases.seekg(0);
+
     std::string line;
     std::vector<prometheus::Labels> result;
     auto labels = std::array{ "time", "mac", "ip", "host", "id" };
 
-    while(std::getline(leases, line)) {
+    while(std::getline(_leases, line)) {
         prometheus::Labels lineMap;
-        for(const auto [index, item]: std::views::split(line, ' ') | std::views::enumerate) {
+        for(const auto [index, item]: std::views::split(line, ' ') | views::enumerate) {
             lineMap[labels[index]] = std::string_view(item);
         }
         result.push_back(lineMap);

DataSources/DnsmasqSource.h

@@ -10,6 +10,18 @@
 #include <vector>
 
 class DnsmasqSource {
+public:
+    enum LeaseField: int {
+        EXPIRY_TIME = 0,
+        MAC         = 1,
+        IP          = 2,
+        HOST        = 3,
+        ID          = 4
+    };
+
+private:
+    std::ifstream _leases;
+
 public:
     DnsmasqSource();
     std::vector<prometheus::Labels> readLeases();

main.cpp

@@ -24,6 +24,7 @@ int main() {
         std::this_thread::sleep_for(std::chrono::seconds(1));
         for(const auto& leaseLabels: dnsmasq.readLeases()) {
             gouge.Add(leaseLabels).Set(1);
+            std::cout << "mac: " << leaseLabels.at("mac") << std::endl;
         }
     }