Add per-node health checks with status indicators and scheduled probes.

service/internal/auth/ping_test.go

@@ -0,0 +1,96 @@
+package auth
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestPingHostUsesICMPWhenAvailable(t *testing.T) {
+	originalPing := runICMPPing
+	originalDial := dialTCP
+	t.Cleanup(func() {
+		runICMPPing = originalPing
+		dialTCP = originalDial
+	})
+
+	runICMPPing = func(hostIP string) error {
+		if hostIP != "10.0.0.1" {
+			t.Fatalf("host = %q", hostIP)
+		}
+		return nil
+	}
+	dialTCP = func(address string, timeout time.Duration) error {
+		t.Fatal("tcp should not be used when icmp succeeds")
+		return nil
+	}
+
+	result := PingHost("10.0.0.1")
+	if !result.OK {
+		t.Fatalf("expected ok, got %#v", result)
+	}
+	if result.Method != PingMethodICMP {
+		t.Fatalf("method = %q", result.Method)
+	}
+}
+
+func TestPingHostFallsBackToTCPWhenICMPFails(t *testing.T) {
+	originalPing := runICMPPing
+	originalDial := dialTCP
+	t.Cleanup(func() {
+		runICMPPing = originalPing
+		dialTCP = originalDial
+	})
+
+	runICMPPing = func(hostIP string) error {
+		return errors.New("ping unavailable: executable file not found")
+	}
+	dialTCP = func(address string, timeout time.Duration) error {
+		if address != "10.0.0.2:22" {
+			t.Fatalf("address = %q", address)
+		}
+		return nil
+	}
+
+	result := PingHost("10.0.0.2")
+	if !result.OK {
+		t.Fatalf("expected ok, got %#v", result)
+	}
+	if result.Method != PingMethodTCP {
+		t.Fatalf("method = %q", result.Method)
+	}
+}
+
+func TestPingHostFailsWhenBothFail(t *testing.T) {
+	originalPing := runICMPPing
+	originalDial := dialTCP
+	t.Cleanup(func() {
+		runICMPPing = originalPing
+		dialTCP = originalDial
+	})
+
+	runICMPPing = func(hostIP string) error {
+		return errors.New("100% packet loss")
+	}
+	dialTCP = func(address string, timeout time.Duration) error {
+		return errors.New("connection refused")
+	}
+
+	result := PingHost("10.0.0.3")
+	if result.OK {
+		t.Fatal("expected failure")
+	}
+	if result.Error == nil {
+		t.Fatal("expected error")
+	}
+	if result.Method != PingMethodTCP {
+		t.Fatalf("method = %q", result.Method)
+	}
+}
+
+func TestPingHostRequiresHostIP(t *testing.T) {
+	result := PingHost("  ")
+	if result.OK || result.Error == nil {
+		t.Fatalf("expected failure, got %#v", result)
+	}
+}