vrrp: T1884: Keep transition-script native behaviour and implement tr…

interface-definitions/vrrp.xml.in

@@ -197,6 +197,14 @@
                       </constraint>
                     </properties>
                   </leafNode>
+                  <leafNode name="stop">
+                    <properties>
+                      <help>Script to run on VRRP state transition to stop</help>
+                      <constraint>
+                        <validator name="script"/>
+                      </constraint>
+                    </properties>
+                  </leafNode>
                 </children>
               </node>
               <leafNode name="virtual-address">

python/vyos/keepalived.py

@@ -26,8 +26,6 @@
 stats_file = '/tmp/keepalived.stats'
 json_file = '/tmp/keepalived.json'
 
-state_dir = '/var/run/vyos/vrrp/'
-
 def vrrp_running():
     if not os.path.exists(vyos.keepalived.pid_file) \
       or not vyos.util.process_running(vyos.keepalived.pid_file):
@@ -38,6 +36,15 @@ def vrrp_running():
 def keepalived_running():
     return vyos.util.process_running(pid_file)
 
+## Clear VRRP data after showing
+def remove_vrrp_data(data_file):
+    if data_file == "json" and os.path.exists(json_file):
+        os.remove(json_file)
+    elif data_file == "stats" and os.path.exists(stats_file):
+        os.remove(stats_file)
+    elif data_file == "state" and os.path.exists(state_file):
+        os.remove(state_file)
+
 def force_state_data_dump():
     pid = vyos.util.read_file(pid_file)
     os.kill(int(pid), signal.SIGUSR1)
@@ -76,26 +83,6 @@ def decode_state(code):
 
     return state
 
-## The functions are mainly for transition script wrappers
-## to compensate for the fact that keepalived doesn't keep persistent
-## state between reloads.
-def get_old_state(group):
-    file = os.path.join(state_dir, "{0}.state".format(group))
-    if os.path.exists(file):
-        with open(file, 'r') as f:
-            data = f.read().strip()
-            return data
-    else:
-       return None
-
-def save_state(group, state):
-    if not os.path.exists(state_dir):
-        os.makedirs(state_dir)
-
-    file = os.path.join(state_dir, "{0}.state".format(group))
-    with open(file, 'w') as f:
-        f.write(state)
-
 ## These functions are for the old, and hopefully obsolete plaintext
 ## (non machine-readable) data format introduced by Vyatta back in the days
 ## They are kept here just in case, if JSON output option turns out or becomes

src/conf_mode/vrrp.py

@@ -37,6 +37,7 @@
 
 global_defs {
     dynamic_interfaces
+    script_user root
 }
 
 {% for group in groups -%}
@@ -117,6 +118,10 @@
     {% if group.fault_script -%}
         notify_fault "/usr/libexec/vyos/system/vrrp-script-wrapper.py --state fault --group {{ group.name }} --interface {{ group.interface }} {{ group.fault_script }}"
     {% endif -%}
+
+    {% if group.stop_script -%}
+        notify_stop "/usr/libexec/vyos/system/vrrp-script-wrapper.py --state stop --group {{ group.name }} --interface {{ group.interface }} {{ group.stop_script }}"
+    {% endif -%}
 }
 
 {% endfor -%}
@@ -178,6 +183,7 @@ def get_config():
         group["master_script"] = config.return_value("transition-script master")
         group["backup_script"] = config.return_value("transition-script backup")
         group["fault_script"] = config.return_value("transition-script fault")
+        group["stop_script"] = config.return_value("transition-script stop")
 
         if config.exists("no-preempt"):
             group["preempt"] = False

src/op_mode/vrrp.py

@@ -32,6 +32,7 @@ def print_summary():
         # Replace with inotify or similar if it proves problematic
         time.sleep(0.2)
         json_data = vyos.keepalived.get_json_data()
+        vyos.keepalived.remove_vrrp_data("json")
     except:
         print("VRRP information is not available")
         sys.exit(1)
@@ -63,6 +64,7 @@ def print_statistics():
         time.sleep(0.2)
         output = vyos.keepalived.get_statistics()
         print(output)
+        vyos.keepalived.remove_vrrp_data("stats")
     except:
         print("VRRP statistics are not available")
         sys.exit(1)
@@ -73,6 +75,7 @@ def print_state_data():
         time.sleep(0.2)
         output = vyos.keepalived.get_state_data()
         print(output)
+        vyos.keepalived.remove_vrrp_data("state")
     except:
         print("VRRP information is not available")
         sys.exit(1)

src/system/vrrp-script-wrapper.py

@@ -23,7 +23,6 @@
 import syslog
 
 import vyos.util
-import vyos.keepalived
 
 
 parser = argparse.ArgumentParser()
@@ -44,38 +43,22 @@
 # to pass arguments to the script
 args.script = " ".join(args.script)
 
-# Get the old state if it exists and compare it to the current state received
-# in command line options to avoid executing scripts if no real transition occured.
-# This is necessary because keepalived does not keep persistent state data even between
-# config reloads and will cheerfully execute everything whether it's required or not.
-
-old_state = vyos.keepalived.get_old_state(args.group)
-
-if (old_state is None) or (old_state != args.state):
-    exitcode = 0
-
-    # Run the script and save the new state
-
-    # Change the process GID to the config owners group to avoid screwing up
-    # running config permissions
-    os.setgid(vyos.util.get_cfg_group_id())
-
-    syslog.syslog(syslog.LOG_NOTICE, 'Running transition script {0} for VRRP group {1}'.format(args.script, args.group))
-    try:
-       ret = subprocess.call("%s %s %s %s" % ( args.script, args.state, args.interface, args.group), shell=True)
-       if ret != 0:
-           syslog.syslog(syslog.LOG_ERR, "Transition script {0} failed, exit status: {1}".format(args.script, ret))
-           exitcode = ret
-    except Exception as e:
-        syslog.syslog(syslog.LOG_ERR, "Failed to execute transition script {0}: {1}".format(args.script, e))
-        exitcode = 1
-
-    if exitcode == 0:
-        syslog.syslog(syslog.LOG_NOTICE, "Transition script {0} executed successfully".format(args.script))
-
-    vyos.keepalived.save_state(args.group, args.state)
-else:
-    syslog.syslog(syslog.LOG_NOTICE, "State of the group {0} has not changed, not running transition script".format(args.group))
+exitcode = 0
+# Change the process GID to the config owners group to avoid screwing up
+# running config permissions
+os.setgid(vyos.util.get_cfg_group_id())
+syslog.syslog(syslog.LOG_NOTICE, 'Running transition script {0} for VRRP group {1}'.format(args.script, args.group))
+try:
+    ret = subprocess.call("%s %s %s %s" % ( args.script, args.state, args.interface, args.group), shell=True)
+    if ret != 0:
+        syslog.syslog(syslog.LOG_ERR, "Transition script {0} failed, exit status: {1}".format(args.script, ret))
+        exitcode = ret
+except Exception as e:
+    syslog.syslog(syslog.LOG_ERR, "Failed to execute transition script {0}: {1}".format(args.script, e))
+    exitcode = 1
+
+if exitcode == 0:
+    syslog.syslog(syslog.LOG_NOTICE, "Transition script {0} executed successfully".format(args.script))
 
 syslog.closelog()
 sys.exit(exitcode)