feat: initial commit — uptime monitor (forked from go-upkeep)

Go-based uptime monitor with SQLite/Postgres storage, TUI dashboard, SSH server, alerting, and clustering support.
2026-05-14 11:05:10 -04:00
commit 02f0a39d97
25 changed files with 2834 additions and 0 deletions
@@ -0,0 +1,69 @@
+package cluster
+
+import (
+	"fmt"
+	"go-upkeep/internal/monitor"
+	"net/http"
+	"time"
+)
+
+type Config struct {
+	Mode       string // "leader" or "follower"
+	PeerURL    string // URL of the Leader (e.g., http://primary:8080)
+	SharedKey  string // Security Key
+}
+
+func Start(cfg Config) {
+	if cfg.Mode == "leader" {
+		fmt.Println("Cluster: Running as LEADER (Active)")
+		monitor.SetEngineActive(true)
+		return
+	}
+
+	if cfg.Mode == "follower" {
+		fmt.Println("Cluster: Running as FOLLOWER (Passive)")
+		monitor.SetEngineActive(false) // Start passive
+		go runFollowerLoop(cfg)
+	}
+}
+
+func runFollowerLoop(cfg Config) {
+	client := http.Client{Timeout: 2 * time.Second}
+	
+	// Failover Configuration
+	failures := 0
+	threshold := 3 
+
+	for {
+		time.Sleep(5 * time.Second)
+
+		req, _ := http.NewRequest("GET", cfg.PeerURL+"/api/health", nil)
+		if cfg.SharedKey != "" {
+			req.Header.Set("X-Upkeep-Secret", cfg.SharedKey)
+		}
+
+		resp, err := client.Do(req)
+		isLeaderHealthy := false
+		
+		if err == nil && resp.StatusCode == 200 {
+			isLeaderHealthy = true
+			resp.Body.Close()
+		}
+
+		if isLeaderHealthy {
+			failures = 0
+			if monitor.IsEngineActive() {
+				// Leader is back, yield
+				monitor.SetEngineActive(false)
+				monitor.AddLog("Cluster: Leader detected. Switching to PASSIVE.")
+			}
+		} else {
+			failures++
+			// If failures exceed threshold, take over
+			if failures >= threshold && !monitor.IsEngineActive() {
+				monitor.SetEngineActive(true)
+				monitor.AddLog("Cluster: Leader Unreachable. Switching to ACTIVE.")
+			}
+		}
+	}
+}