checker: split monolithic rule into per-concern rules

checker/rules_reachability.go

@@ -0,0 +1,70 @@
+// 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"
+)
+
+// reachabilityRule verifies each target replied to at least one probe.
+// A target with 100% packet loss is considered unreachable.
+type reachabilityRule struct{}
+
+func (r *reachabilityRule) Name() string { return "ping.reachable" }
+func (r *reachabilityRule) Description() string {
+	return "Verifies every target replied to at least one ICMP probe."
+}
+
+func (r *reachabilityRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ 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.reachable.no_targets")}
+	}
+
+	out := make([]sdk.CheckState, 0, len(data.Targets))
+	for _, t := range data.Targets {
+		if t.Received == 0 {
+			out = append(out, sdk.CheckState{
+				Status:  sdk.StatusCrit,
+				Subject: t.Address,
+				Message: fmt.Sprintf("Target unreachable (0/%d replies).", t.Sent),
+				Code:    "ping.reachable.unreachable",
+				Meta:    map[string]any{"target": t},
+			})
+		} else {
+			out = append(out, sdk.CheckState{
+				Status:  sdk.StatusOK,
+				Subject: t.Address,
+				Message: fmt.Sprintf("Target reachable (%d/%d replies).", t.Received, t.Sent),
+				Code:    "ping.reachable.ok",
+				Meta:    map[string]any{"target": t},
+			})
+		}
+	}
+	return out
+}