Ability to run script before/after live migrations

Author: remibergsma

cloudstackops/xenserver.py

@@ -49,9 +49,12 @@
 # Class to handle XenServer patching
 class xenserver():
 
-    def __init__(self, ssh_user='root', threads=5):
+    def __init__(self, ssh_user='root', threads=5, pre_empty_script='xenserver_pre_empty_script.sh',
+                 post_empty_script='xenserver_post_empty_script.sh'):
         self.ssh_user = ssh_user
         self.threads = threads
+        self.pre_empty_script = pre_empty_script
+        self.post_empty_script = post_empty_script
 
     # Wait for hypervisor to become alive again
     def check_connect(self, host):
@@ -169,11 +172,16 @@ def host_evacuate(self, host):
 
     # Reboot a host when all conditions are met
     def host_reboot(self, host, halt_hypervisor=False):
-        # Disbale host
+        # Disable host
         if self.host_disable(host) is False:
             print "Error: Disabling host " + host.name + " failed."
             return False
 
+        # Execute pre-empty-script
+        if self.exec_script_on_hypervisor(host, self.pre_empty_script) is False:
+            print "Error: Executing script '" + self.pre_empty_script + "' on host " + host.name + " failed."
+            return False
+
         # Then evacuate it
         if self.host_evacuate(host) is False:
             print "Error: Evacuating host " + host.name + " failed."
@@ -185,6 +193,11 @@ def host_reboot(self, host, halt_hypervisor=False):
             return False
         print "Note: Host " + host.name + " has no VMs running, continuing"
 
+        # Execute post-empty-script
+        if self.exec_script_on_hypervisor(host, self.post_empty_script) is False:
+            print "Error: Executing script '" + self.post_empty_script + "' on host " + host.name + " failed."
+            return False
+
         # Finally reboot it
         try:
             with settings(host_string=self.ssh_user + "@" + host.ipaddress):
@@ -209,6 +222,15 @@ def host_reboot(self, host, halt_hypervisor=False):
             print "Error: Enabling host " + host.name + " failed."
             return False
 
+    # Execute script on hypervisor
+    def exec_script_on_hypervisor(self, host, script):
+        print "Note: Executing script %s on host %s.." % (script, host.name)
+        try:
+            with settings(show('output'), host_string=self.ssh_user + "@" + host.ipaddress):
+                return fab.run("bash /tmp/" + script)
+        except:
+            return False
+
     # Get VM count of a hypervisor
     def host_get_vms(self, host):
         try:
@@ -275,6 +297,12 @@ def put_scripts(self, host):
                     '/tmp/xenserver_fake_pvtools.sh', mode=0755)
                 put('xenserver_parallel_evacuate.py',
                     '/tmp/xenserver_parallel_evacuate.py', mode=0755)
+                if len(self.pre_empty_script) > 0:
+                    put(self.pre_empty_script,
+                        '/tmp/' + self.pre_empty_script, mode=0755)
+                if len(self.post_empty_script) > 0:
+                    put(self.post_empty_script,
+                        '/tmp/' + self.post_empty_script, mode=0755)
             return True
         except:
             print "Warning: Could not upload check scripts to host " + host.name + ". Continuing anyway."

xenserver_post_empty_script.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+echo "This is the post_empty script you could customise."

xenserver_pre_empty_script.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+echo "This is the pre_empty script you could customise."

xenserver_rolling_reboot.py

@@ -57,7 +57,10 @@ def handleArguments(argv):
     threads = 5
     global halt_hypervisor
     halt_hypervisor = False
-
+    global pre_empty_script
+    pre_empty_script = 'xenserver_pre_empty_script.sh'
+    global post_empty_script
+    post_empty_script = 'xenserver_post_empty_script.sh'
     # Usage message
     help = "Usage: ./" + os.path.basename(__file__) + ' [options]' + \
         '\n  --config-profile -c <profilename>\t\tSpecify the CloudMonkey profile name to ' \
@@ -68,14 +71,19 @@ def handleArguments(argv):
         '\n  --threads <nr>\t\t\t\tUse this number or concurrent migration threads ' + \
         '\n  --halt\t\t\t\t\tInstead of the default reboot, halt the hypervisor (useful in case of hardware ' \
         'upgrades) ' + \
+        '\n  --pre-empty-script\t\t\t\tBash script to run on hypervisor before starting the live migrations to empty ' \
+        'hypervisor (expected in same folder as this script)' + \
+        '\n  --post-empty-script\t\t\t\tBash script to run on hypervisor after a hypervisor has no more VMs running' \
+        '(expected in same folder as this script)' + \
         '\n  --debug\t\t\t\t\tEnable debug mode' + \
         '\n  --exec\t\t\t\t\tExecute for real' + \
         '\n  --prepare\t\t\t\t\tExecute some prepare commands'
 
     try:
         opts, args = getopt.getopt(
             argv, "hc:n:t:p", [
-                "credentials-file=", "clustername=", "ignore-hosts=", "threads=", "halt", "debug", "exec", "prepare"])
+                "credentials-file=", "clustername=", "ignore-hosts=", "threads=", "pre-empty-script=",
+                "post-empty-script=", "halt", "debug", "exec", "prepare"])
     except getopt.GetoptError as e:
         print "Error: " + str(e)
         print help
@@ -95,6 +103,10 @@ def handleArguments(argv):
             ignoreHostList = arg
         elif opt in ("--halt"):
             halt_hypervisor = True
+        elif opt in ("--pre-empty-script"):
+            pre_empty_script = arg
+        elif opt in ("--post-empty-script"):
+            post_empty_script = arg
         elif opt in ("--debug"):
             DEBUG = 1
         elif opt in ("--exec"):