Use build-in selector and respect limits in client

Use the new built-in selector option, as well as respecting node limits,
when performing migrate or move actions on a VM via the clients.

client-api/api_lib/pvcapi.py

@@ -425,12 +425,12 @@ def vm_stop(name):
     }
     return flask.jsonify(output), retcode
 
-def vm_move(name, node, selector):
+def vm_move(name, node):
     """
     Move a VM to another node.
     """
     zk_conn = pvc_common.startZKConnection(config['coordinators'])
-    retflag, retdata = pvc_vm.move_vm(zk_conn, name, node, selector)
+    retflag, retdata = pvc_vm.move_vm(zk_conn, name, node)
     if retflag:
         retcode = 200
     else:
@@ -442,12 +442,12 @@ def vm_move(name, node, selector):
     }
     return flask.jsonify(output), retcode
 
-def vm_migrate(name, node, selector, flag_force):
+def vm_migrate(name, node, flag_force):
     """
     Temporarily migrate a VM to another node.
     """
     zk_conn = pvc_common.startZKConnection(config['coordinators'])
-    retflag, retdata = pvc_vm.migrate_vm(zk_conn, name, node, selector, flag_force)
+    retflag, retdata = pvc_vm.migrate_vm(zk_conn, name, node, flag_force)
     if retflag:
         retcode = 200
     else:

client-api/pvc-api.py

@@ -338,11 +338,6 @@ def api_vm_node(vm):
             node = flask.request.values['node']
         else:
             node = None
-        # Get target selector
-        if 'selector' in flask.request.values:
-            selector = flask.request.values['selector']
-        else:
-            selector = None
         # Get permanent flag
         if 'permanent' in flask.request.values and flask.request.values['permanent']:
             flag_permanent = True
@@ -358,9 +353,9 @@ def api_vm_node(vm):
         is_migrated = pvcapi.vm_is_migrated(vm)
 
         if action == 'migrate' and not flag_permanent:
-            return pvcapi.vm_migrate(vm, node, selector, flag_force)
+            return pvcapi.vm_migrate(vm, node, flag_force)
         if action == 'migrate' and flag_permanent:
-            return pvcapi.vm_move(vm, node, selector)
+            return pvcapi.vm_move(vm, node)
         if action == 'unmigrate' and is_migrated:
             return pvcapi.vm_unmigrate(vm)
 

client-cli/pvc.py

@@ -520,19 +520,14 @@ def vm_stop(domain):
     '-t', '--target', 'target_node', default=None,
     help='Target node to migrate to; autodetect if unspecified.'
 )
-@click.option(
+def vm_move(domain, target_node):
-    '-s', '--selector', 'selector', default='mem', show_default=True,
-    type=click.Choice(['mem','load','vcpus','vms']),
-    help='Method to determine optimal target node during autodetect.'
-)
-def vm_move(domain, target_node, selector):
     """
     Permanently move virtual machine DOMAIN, via live migration if running and possible, to another node. DOMAIN may be a UUID or name.
     """
 
     # Open a Zookeeper connection
     zk_conn = pvc_common.startZKConnection(zk_host)
-    retcode, retmsg = pvc_vm.move_vm(zk_conn, domain, target_node, selector)
+    retcode, retmsg = pvc_vm.move_vm(zk_conn, domain, target_node)
     cleanup(retcode, retmsg, zk_conn)
 
 ###############################################################################
@@ -546,23 +541,18 @@ def vm_move(domain, target_node, selector):
     '-t', '--target', 'target_node', default=None,
     help='Target node to migrate to; autodetect if unspecified.'
 )
-@click.option(
-    '-s', '--selector', 'selector', default='mem', show_default=True,
-    type=click.Choice(['mem','load','vcpus','vms']),
-    help='Method to determine optimal target node during autodetect.'
-)
 @click.option(
     '-f', '--force', 'force_migrate', is_flag=True, default=False,
     help='Force migrate an already migrated VM; does not replace an existing previous node value.'
 )
-def vm_migrate(domain, target_node, selector, force_migrate):
+def vm_migrate(domain, target_node, force_migrate):
     """
     Temporarily migrate running virtual machine DOMAIN, via live migration if possible, to another node. DOMAIN may be a UUID or name. If DOMAIN is not running, it will be started on the target node.
     """
 
     # Open a Zookeeper connection
     zk_conn = pvc_common.startZKConnection(zk_host)
-    retcode, retmsg = pvc_vm.migrate_vm(zk_conn, domain, target_node, selector, force_migrate, is_cli=True)
+    retcode, retmsg = pvc_vm.migrate_vm(zk_conn, domain, target_node, force_migrate, is_cli=True)
     cleanup(retcode, retmsg, zk_conn)
 
 ###############################################################################

client-common/common.py

@@ -288,18 +288,46 @@ def getPrimaryNode(zk_conn):
     return primary_node
 
 #
-# Get the list of valid target nodes
+# Find a migration target
 #
-def getNodes(zk_conn, dom_uuid):
+def findTargetHypervisor(zk_conn, config, dom_uuid):
+    # Determine VM node limits; set config value if read fails
+    try:
+        node_limit = zkhandler.readdata(zk_conn, '/domains/{}/node_limit'.format(node)).split(',')
+    except:
+        node_limit = None
+        zkhandler.writedata(zk_conn, { '/domains/{}/node_limit'.format(node): 'None' })
+
+    # Determine VM search field or use default; set config value if read fails
+    try:
+        search_field = zkhandler.readdata(zk_conn, '/domains/{}/node_selector'.format(node)).split(',')
+    except:
+        search_field = config.migration_target_selector
+        zkhandler.writedata(zk_conn, { '/domains/{}/node_selector'.format(node): config.migration_target_selector })
+
+    # Execute the search
+    if search_field == 'mem':
+        return findTargetHypervisorMem(zk_conn, node_limit, dom_uuid)
+    if search_field == 'load':
+        return findTargetHypervisorLoad(zk_conn, node_limit, dom_uuid)
+    if search_field == 'vcpus':
+        return findTargetHypervisorVCPUs(zk_conn, node_limit, dom_uuid)
+    if search_field == 'vms':
+        return findTargetHypervisorVMs(zk_conn, node_limit, dom_uuid)
+
+    # Nothing was found
+    return None
+
+# Get the list of valid target nodes
+def getHypervisors(zk_conn, node_limit, dom_uuid):
     valid_node_list = []
     full_node_list = zkhandler.listchildren(zk_conn, '/nodes')
-
+    current_node = zkhandler.readdata(zk_conn, '/domains/{}/node'.format(dom_uuid))
-    try:
-        current_node = zkhandler.readdata(zk_conn, '/domains/{}/node'.format(dom_uuid))
-    except:
-        current_node = None
 
     for node in full_node_list:
+        if node_limit and node not in node_limit:
+            continue
+
         daemon_state = zkhandler.readdata(zk_conn, '/nodes/{}/daemonstate'.format(node))
         domain_state = zkhandler.readdata(zk_conn, '/nodes/{}/domainstate'.format(node))
 
@@ -311,64 +339,50 @@ def getNodes(zk_conn, dom_uuid):
 
         valid_node_list.append(node)
 
-    if not valid_node_list:
-        # We found no valid nodes; possibly they're all flushed or all down. Return the entire list instead.
-        valid_node_list = full_node_list
-
     return valid_node_list
-    
-#
-# Find a migration target
-#
-def findTargetNode(zk_conn, search_field, dom_uuid):
-    if search_field == 'mem':
-        return findTargetNodeMem(zk_conn, dom_uuid)
-    if search_field == 'load':
-        return findTargetNodeLoad(zk_conn, dom_uuid)
-    if search_field == 'vcpus':
-        return findTargetNodeVCPUs(zk_conn, dom_uuid)
-    if search_field == 'vms':
-        return findTargetNodeVMs(zk_conn, dom_uuid)
-    return None
 
-# via allocated memory
+# via free memory (relative to allocated memory)
-def findTargetNodeMem(zk_conn, dom_uuid):
+def findTargetHypervisorMem(zk_conn, node_limit, dom_uuid):
-    least_alloc = math.inf
+    most_allocfree = 0
     target_node = None
 
-    node_list = getNodes(zk_conn, dom_uuid)
+    node_list = getHypervisors(zk_conn, node_limit, dom_uuid)
     for node in node_list:
-        alloc = float(zkhandler.readdata(zk_conn, '/nodes/{}/memalloc'.format(node)))
+        memalloc = int(zkhandler.readdata(zk_conn, '/nodes/{}/memalloc'.format(node)))
+        memused = int(zkhandler.readdata(zk_conn, '/nodes/{}/memused'.format(node)))
+        memfree = int(zkhandler.readdata(zk_conn, '/nodes/{}/memfree'.format(node)))
+        memtotal = memused + memfree
+        allocfree = memtotal - memalloc
 
-        if alloc < least_alloc:
+        if allocfree > most_allocfree:
-            least_alloc = alloc
+            most_allocfree = allocfree
             target_node = node
 
     return target_node
 
 # via load average
-def findTargetNodeLoad(zk_conn, dom_uuid):
+def findTargetHypervisorLoad(zk_conn, node_limit, dom_uuid):
-    least_load = math.inf
+    least_load = 9999
     target_node = None
 
-    node_list = getNodes(zk_conn, dom_uuid)
+    node_list = getHypervisors(zk_conn, node_limit, dom_uuid)
     for node in node_list:
-        load = float(zkhandler.readdata(zk_conn, '/nodes/{}/cpuload'.format(node)))
+        load = int(zkhandler.readdata(zk_conn, '/nodes/{}/load'.format(node)))
 
         if load < least_load:
             least_load = load
-            target_node = node
+            target_hypevisor = node
 
     return target_node
 
 # via total vCPUs
-def findTargetNodeVCPUs(zk_conn, dom_uuid):
+def findTargetHypervisorVCPUs(zk_conn, node_limit, dom_uuid):
-    least_vcpus = math.inf
+    least_vcpus = 9999
     target_node = None
 
-    node_list = getNodes(zk_conn, dom_uuid)
+    node_list = getHypervisors(zk_conn, node_limit, dom_uuid)
     for node in node_list:
-        vcpus = float(zkhandler.readdata(zk_conn, '/nodes/{}/vcpualloc'.format(node)))
+        vcpus = int(zkhandler.readdata(zk_conn, '/nodes/{}/vcpualloc'.format(node)))
 
         if vcpus < least_vcpus:
             least_vcpus = vcpus
@@ -377,13 +391,13 @@ def findTargetNodeVCPUs(zk_conn, dom_uuid):
     return target_node
 
 # via total VMs
-def findTargetNodeVMs(zk_conn, dom_uuid):
+def findTargetHypervisorVMs(zk_conn, node_limit, dom_uuid):
-    least_vms = math.inf
+    least_vms = 9999
     target_node = None
 
-    node_list = getNodes(zk_conn, dom_uuid)
+    node_list = getHypervisors(zk_conn, node_limit, dom_uuid)
     for node in node_list:
-        vms = float(zkhandler.readdata(zk_conn, '/nodes/{}/domainscount'.format(node)))
+        vms = int(zkhandler.readdata(zk_conn, '/nodes/{}/domainscount'.format(node)))
 
         if vms < least_vms:
             least_vms = vms

client-common/vm.py

@@ -398,7 +398,7 @@ def stop_vm(zk_conn, domain):
 
     return True, 'Forcibly stopping VM "{}".'.format(domain)
 
-def move_vm(zk_conn, domain, target_node, selector):
+def move_vm(zk_conn, domain, target_node):
     # Validate that VM exists in cluster
     dom_uuid = getDomainUUID(zk_conn, domain)
     if not dom_uuid:
@@ -408,13 +408,18 @@ def move_vm(zk_conn, domain, target_node, selector):
     current_node = zkhandler.readdata(zk_conn, '/domains/{}/node'.format(dom_uuid))
 
     if not target_node:
-        target_node = common.findTargetNode(zk_conn, selector, dom_uuid)
+        target_node = common.findTargetNode(zk_conn, dom_uuid)
     else:
         # Verify node is valid
         valid_node = common.verifyNode(zk_conn, target_node)
         if not valid_node:
             return False, 'Specified node "{}" is invalid.'.format(target_node)
 
+        # Check if node is within the limit
+        limit = zkhandler.readdata(zk_conn, '/domains/{}/node_limit'.format(dom_uuid).split(',')
+        if target_node not in limit:
+            return False, 'Specified node "{}" is not in the allowed list of nodes for VM "{}".'.format(target_node, domain)
+
         # Verify if node is current node
         if target_node == current_node:
             common.stopZKConnection(zk_conn)
@@ -435,7 +440,7 @@ def move_vm(zk_conn, domain, target_node, selector):
 
     return True, 'Permanently migrating VM "{}" to node "{}".'.format(domain, target_node)
 
-def migrate_vm(zk_conn, domain, target_node, selector, force_migrate, is_cli=False):
+def migrate_vm(zk_conn, domain, target_node, force_migrate, is_cli=False):
     # Validate that VM exists in cluster
     dom_uuid = getDomainUUID(zk_conn, domain)
     if not dom_uuid:
@@ -463,13 +468,18 @@ def migrate_vm(zk_conn, domain, target_node, selector, force_migrate, is_cli=Fal
             return False, 'ERROR: VM "{}" has been previously migrated.'.format(domain)
 
     if not target_node:
-        target_node = common.findTargetNode(zk_conn, selector, dom_uuid)
+        target_node = common.findTargetNode(zk_conn, dom_uuid)
     else:
         # Verify node is valid
         valid_node = common.verifyNode(zk_conn, target_node)
         if not valid_node:
             return False, 'Specified node "{}" is invalid.'.format(target_node)
 
+        # Check if node is within the limit
+        limit = zkhandler.readdata(zk_conn, '/domains/{}/node_limit'.format(dom_uuid).split(',')
+        if target_node not in limit:
+            return False, 'Specified node "{}" is not in the allowed list of nodes for VM "{}".'.format(target_node, domain)
+
         # Verify if node is current node
         if target_node == current_node:
             common.stopZKConnection(zk_conn)