Add hook system

files/config.yml

@@ -23,6 +23,27 @@
 
 #dns_ip: 127.0.0.1
 
+#
+# Optional path to the hooks base directory (default: <etc_dir>/hooks).
+# Executable files placed in this tree are run around zone and record mutations. The tree narrows
+# progressively; every level is optional and a hook fires for every event along its path:
+#
+#   hooks/                          -> every action and phase (zone+record, add+delete, pre+post)
+#   hooks/<kind>/                   -> all actions/phases of <kind> (zone|record)
+#   hooks/<kind>/<action>/          -> both phases of <action> (add|delete)
+#   hooks/<kind>/<action>/<phase>/  -> single phase only (pre|post)
+#
+# All matching hooks across all levels are collected and run sorted by filename (run-parts style);
+# only executable files are run. Each hook inherits the terminal: stdout/stderr appear live and it
+# may be interactive (prompt and read stdin). In batch mode (-b) stdin is /dev/null, so reads get EOF.
+# A pre-hook exiting non-zero aborts the operation (exit code 190); a post-hook failure prints an ERROR and continues.
+# Hooks receive context via env vars (DNSMGR_KIND/ACTION/PHASE/ZONE/VIEW and, for records,
+# DNSMGR_RECORD_NAME/TTL/TYPE/VALUE).
+# DNSMGR_ZONE_FILE (zone file path) is set only for managed zones and and not for zone add pre-hooks nor for zone delete post-hooks.
+#
+
+#hooks_dir: /etc/dns-manager/hooks
+
 #
 # Dictionary of paths to key files (TSIG) per view used for zone transfers and DDNS updates.
 # This option is mandatory when using views other than the default (_default) or if the usage of a key