Initial commit

checker/rule.go

@@ -0,0 +1,147 @@
+package checker
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"strings"
+
+	sdk "git.happydns.org/checker-sdk-go/checker"
+)
+
+func Rule() sdk.CheckRule {
+	return &xmppRule{}
+}
+
+type xmppRule struct{}
+
+func (r *xmppRule) Name() string {
+	return "xmpp_server"
+}
+
+func (r *xmppRule) Description() string {
+	return "Checks discovery, STARTTLS, SASL and federation auth of an XMPP server"
+}
+
+func (r *xmppRule) ValidateOptions(opts sdk.CheckerOptions) error {
+	if v, ok := opts["mode"]; ok {
+		if s, ok := v.(string); ok && s != "" && !slices.Contains(validModes, s) {
+			return fmt.Errorf(`mode must be "c2s", "s2s", or "both"`)
+		}
+	}
+	return nil
+}
+
+func (r *xmppRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) sdk.CheckState {
+	var data XMPPData
+	if err := obs.Get(ctx, ObservationKeyXMPP, &data); err != nil {
+		return sdk.CheckState{
+			Status:  sdk.StatusError,
+			Message: fmt.Sprintf("failed to load XMPP observation: %v", err),
+			Code:    "xmpp.observation_error",
+		}
+	}
+
+	issues := append([]Issue(nil), data.Issues...)
+
+	// Fold related TLS observations (from a downstream TLS checker, if any)
+	// into the XMPP issue list so cert/chain problems show up on the XMPP
+	// service page without requiring a separate glance at the TLS checker.
+	related, _ := obs.GetRelated(ctx, TLSRelatedKey)
+	issues = append(issues, tlsIssuesFromRelated(related)...)
+
+	// Reduce issue list to the worst severity.
+	worst := sdk.StatusOK
+	critMsgs, warnMsgs := []string{}, []string{}
+	var firstCritCode, firstWarnCode string
+
+	for _, is := range issues {
+		switch is.Severity {
+		case SeverityCrit:
+			if worst < sdk.StatusCrit {
+				worst = sdk.StatusCrit
+			}
+			if firstCritCode == "" {
+				firstCritCode = is.Code
+			}
+			critMsgs = append(critMsgs, is.Message)
+		case SeverityWarn:
+			if worst < sdk.StatusWarn {
+				worst = sdk.StatusWarn
+			}
+			if firstWarnCode == "" {
+				firstWarnCode = is.Code
+			}
+			warnMsgs = append(warnMsgs, is.Message)
+		}
+	}
+
+	mode, _ := sdk.GetOption[string](opts, "mode")
+	if mode == "" {
+		mode = "both"
+	}
+	wantC2S := mode != "s2s"
+	wantS2S := mode != "c2s"
+
+	// Even without issues, the check isn't OK unless we got at least one
+	// working endpoint in each requested mode.
+	if (wantC2S && !data.Coverage.WorkingC2S) || (wantS2S && !data.Coverage.WorkingS2S) {
+		if worst < sdk.StatusCrit {
+			worst = sdk.StatusCrit
+		}
+		var missing []string
+		if wantC2S && !data.Coverage.WorkingC2S {
+			missing = append(missing, "c2s")
+		}
+		if wantS2S && !data.Coverage.WorkingS2S {
+			missing = append(missing, "s2s")
+		}
+		critMsgs = append(critMsgs, "no working "+strings.Join(missing, "/")+" endpoint")
+		if firstCritCode == "" {
+			firstCritCode = CodeAllEndpointsDown
+		}
+	}
+
+	meta := map[string]any{
+		"working_c2s": data.Coverage.WorkingC2S,
+		"working_s2s": data.Coverage.WorkingS2S,
+		"has_ipv4":    data.Coverage.HasIPv4,
+		"has_ipv6":    data.Coverage.HasIPv6,
+		"endpoints":   len(data.Endpoints),
+		"issue_count": len(data.Issues),
+	}
+
+	switch worst {
+	case sdk.StatusOK:
+		return sdk.CheckState{
+			Status:  sdk.StatusOK,
+			Message: fmt.Sprintf("XMPP operational (c2s=%v, s2s=%v, %d endpoints)", data.Coverage.WorkingC2S, data.Coverage.WorkingS2S, len(data.Endpoints)),
+			Code:    "xmpp.ok",
+			Meta:    meta,
+		}
+	case sdk.StatusWarn:
+		return sdk.CheckState{
+			Status:  sdk.StatusWarn,
+			Message: "XMPP works with warnings: " + joinTop(warnMsgs, 2),
+			Code:    firstWarnCode,
+			Meta:    meta,
+		}
+	default:
+		return sdk.CheckState{
+			Status:  sdk.StatusCrit,
+			Message: "XMPP broken: " + joinTop(critMsgs, 2),
+			Code:    firstCritCode,
+			Meta:    meta,
+		}
+	}
+}
+
+func joinTop(msgs []string, n int) string {
+	if len(msgs) == 0 {
+		return ""
+	}
+	if len(msgs) <= n {
+		return strings.Join(msgs, "; ")
+	}
+	return strings.Join(msgs[:n], "; ") + fmt.Sprintf(" (+%d more)", len(msgs)-n)
+}