checker: split monolithic rule into per-concern rules

checker/rules_loss.go

@@ -0,0 +1,88 @@
+// This file is part of the happyDomain (R) project.
+// Copyright (c) 2020-2026 happyDomain
+// Authors: Pierre-Olivier Mercier, et al.
+//
+// This program is offered under a commercial and under the AGPL license.
+// For commercial licensing, contact us at <contact@happydomain.org>.
+//
+// For AGPL licensing:
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package checker
+
+import (
+	"context"
+	"fmt"
+
+	sdk "git.happydns.org/checker-sdk-go/checker"
+)
+
+// packetLossRule evaluates the observed packet-loss ratio of each target
+// against the configured warning/critical thresholds.
+type packetLossRule struct{}
+
+func (r *packetLossRule) Name() string { return "ping.packet_loss" }
+func (r *packetLossRule) Description() string {
+	return "Flags targets whose packet-loss ratio crosses the warning or critical threshold."
+}
+
+func (r *packetLossRule) ValidateOptions(opts sdk.CheckerOptions) error {
+	warn := sdk.GetFloatOption(opts, "warningPacketLoss", 10)
+	crit := sdk.GetFloatOption(opts, "criticalPacketLoss", 50)
+	if warn < 0 || warn > 100 {
+		return fmt.Errorf("warningPacketLoss must be between 0 and 100")
+	}
+	if crit < 0 || crit > 100 {
+		return fmt.Errorf("criticalPacketLoss must be between 0 and 100")
+	}
+	if crit <= warn {
+		return fmt.Errorf("criticalPacketLoss (%v) must be greater than warningPacketLoss (%v)", crit, warn)
+	}
+	return nil
+}
+
+func (r *packetLossRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
+	data, errSt := loadPingData(ctx, obs)
+	if errSt != nil {
+		return []sdk.CheckState{*errSt}
+	}
+	if len(data.Targets) == 0 {
+		return []sdk.CheckState{noTargetsState("ping.packet_loss.no_targets")}
+	}
+
+	warn := sdk.GetFloatOption(opts, "warningPacketLoss", 10)
+	crit := sdk.GetFloatOption(opts, "criticalPacketLoss", 50)
+
+	out := make([]sdk.CheckState, 0, len(data.Targets))
+	for _, t := range data.Targets {
+		state := sdk.CheckState{
+			Subject: t.Address,
+			Message: fmt.Sprintf("Packet loss %.0f%% (warn=%.0f%%, crit=%.0f%%).", t.PacketLoss, warn, crit),
+			Meta:    map[string]any{"target": t},
+		}
+		switch {
+		case t.PacketLoss >= crit:
+			state.Status = sdk.StatusCrit
+			state.Code = "ping.packet_loss.critical"
+		case t.PacketLoss >= warn:
+			state.Status = sdk.StatusWarn
+			state.Code = "ping.packet_loss.warning"
+		default:
+			state.Status = sdk.StatusOK
+			state.Code = "ping.packet_loss.ok"
+		}
+		out = append(out, state)
+	}
+	return out
+}