Initial revisin of healthchecker, inspired by HAProxy

internal/prober/prober.go

@@ -0,0 +1,49 @@
+package prober
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"git.ipng.ch/ipng/vpp-maglev/internal/config"
+	"git.ipng.ch/ipng/vpp-maglev/internal/health"
+)
+
+// ProbeFunc is the signature for a health check probe.
+type ProbeFunc func(ctx context.Context, cfg ProbeConfig) health.ProbeResult
+
+// ProbeConfig holds all parameters needed to execute a single probe.
+type ProbeConfig struct {
+	Target           net.IP        // backend address to probe
+	Port             uint16        // destination port (used by TCP and HTTP probers)
+	ProbeSrc         net.IP        // source address to bind; nil lets the OS choose
+	HealthCheckNetns string        // network namespace name; sockets are created inside it
+	Timeout          time.Duration
+	HTTP             *config.HTTPParams // non-nil for type http/https
+	TCP              *config.TCPParams  // non-nil for type tcp
+}
+
+// ForType returns the ProbeFunc registered for the given healthcheck type.
+// Returns a failing stub for unknown types.
+func ForType(t string) ProbeFunc {
+	switch t {
+	case "icmp":
+		return ICMPProbe
+	case "tcp":
+		return TCPProbe
+	case "http":
+		return HTTPProbe
+	case "https":
+		return HTTPSProbe
+	default:
+		return func(_ context.Context, _ ProbeConfig) health.ProbeResult {
+			return health.ProbeResult{
+				OK:     false,
+				Layer:  health.LayerUnknown,
+				Code:   "UNKNOWN",
+				Detail: fmt.Sprintf("unknown probe type %q", t),
+			}
+		}
+	}
+}