initial commit

internal/auditlog/auditlog.go

@@ -0,0 +1,120 @@
+// Package auditlog records administrative changes made through the web UI, the
+// REST API and the CLI.
+//
+// Audit writes are rare compared to DNS queries, so they are synchronous and
+// best-effort: a failure to record an audit entry is logged but never fails the
+// operation the administrator asked for.
+package auditlog
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"strconv"
+	"strings"
+
+	"github.com/owen/vibedns/internal/database"
+	"github.com/owen/vibedns/internal/models"
+)
+
+// Sources an audit entry can originate from.
+const (
+	SourceWeb    = "web"
+	SourceAPI    = "api"
+	SourceCLI    = "cli"
+	SourceSystem = "system"
+)
+
+// Object types recorded in the audit log.
+const (
+	ObjectZone     = "zone"
+	ObjectRecord   = "record"
+	ObjectNetwork  = "network"
+	ObjectPolicy   = "policy"
+	ObjectList     = "list"
+	ObjectDomain   = "domain"
+	ObjectSettings = "settings"
+	ObjectCache    = "cache"
+	ObjectAdmin    = "admin"
+	ObjectToken    = "api_token"
+	ObjectBackup   = "backup"
+	ObjectConfig   = "config"
+	ObjectQueryLog = "query_log"
+)
+
+// Logger writes audit entries.
+type Logger struct {
+	db  *database.DB
+	log *slog.Logger
+}
+
+// New creates an audit logger.
+func New(db *database.DB, log *slog.Logger) *Logger {
+	return &Logger{db: db, log: log}
+}
+
+// Actor identifies who performed an action and from where.
+type Actor struct {
+	Name     string
+	Source   string
+	ClientIP string
+}
+
+// SystemActor is used for changes the server makes on its own behalf.
+func SystemActor() Actor { return Actor{Name: "system", Source: SourceSystem} }
+
+// CLIActor is used for changes made through the command line.
+func CLIActor() Actor { return Actor{Name: "cli", Source: SourceCLI} }
+
+// Record writes an audit entry. Secrets must never be passed in details: this
+// is enforced by convention at the call sites, which pass names and counts
+// rather than values.
+func (l *Logger) Record(ctx context.Context, a Actor, action, objectType, objectID, objectName, details string) {
+	if l == nil || l.db == nil {
+		return
+	}
+	e := models.AuditEntry{
+		Actor:      a.Name,
+		Source:     defaultString(a.Source, SourceWeb),
+		ClientIP:   a.ClientIP,
+		Action:     action,
+		ObjectType: objectType,
+		ObjectID:   objectID,
+		ObjectName: objectName,
+		Details:    truncate(details, 2000),
+	}
+	if err := l.db.InsertAudit(ctx, e); err != nil {
+		l.log.Error("could not write audit entry", "error", err, "action", action)
+	}
+}
+
+// RecordID is Record with an integer object ID.
+func (l *Logger) RecordID(ctx context.Context, a Actor, action, objectType string, id int64, objectName, details string) {
+	l.Record(ctx, a, action, objectType, strconv.FormatInt(id, 10), objectName, details)
+}
+
+// Changes renders a set of field changes as an audit detail string.
+func Changes(pairs ...string) string {
+	if len(pairs)%2 != 0 {
+		return strings.Join(pairs, " ")
+	}
+	var parts []string
+	for i := 0; i < len(pairs); i += 2 {
+		parts = append(parts, fmt.Sprintf("%s=%s", pairs[i], pairs[i+1]))
+	}
+	return strings.Join(parts, ", ")
+}
+
+func defaultString(v, def string) string {
+	if strings.TrimSpace(v) == "" {
+		return def
+	}
+	return v
+}
+
+func truncate(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	return s[:n] + "..."
+}