From b63f6a29581cf42c72a93715e6a73831cc9dcd13 Mon Sep 17 00:00:00 2001
From: Joshua Boniface <joshua@boniface.me>
Date: Tue, 5 Jun 2018 01:39:59 -0400
Subject: [PATCH] Major work on client-side application

---
 pvc.py  | 412 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 pvcf.py | 119 ++++++++++++++++
 2 files changed, 511 insertions(+), 20 deletions(-)

diff --git a/pvc.py b/pvc.py
index 550e5d46..f66b6a74 100755
--- a/pvc.py
+++ b/pvc.py
@@ -1,43 +1,415 @@
 #!/usr/bin/env python3
 
-import kazoo.client, socket, time
+import kazoo.client, socket, time, click
+import pvcf
 from lxml import objectify
 
-def help():
-    print("pvc - Parallel Virtual Cluster command-line utility")
+zk_host = '127.0.0.1:2181'
 
-def define_domain(domxmlfile):
+this_host = socket.gethostname()
+
+CONTEXT_SETTINGS = dict(help_option_names=['-h', '--help'])
+
+# Creates a new domain based on an XML file
+def define_domain(domxmlfile, target_hypervisor):
     with open(domxmlfile, 'r') as f_domxmlfile:
         data = f_domxmlfile.read()
         f_domxmlfile.close()
 
     parsed_xml = objectify.fromstring(data)
-    domuuid = parsed_xml.uuid
-    print('Adding domain %s to database' % domuuid)
+    domuuid = parsed_xml.uuid.text
+    domname = parsed_xml.name.text
+    print('Adding new VM with Name %s and UUID %s to database' % (domname, domuuid))
 
-    zk = kazoo.client.KazooClient(hosts='127.0.0.1:2181')
-    zk.start()
+    zk = pvcf.startZKConnection(zk_host)
     transaction = zk.transaction()
-    transaction.create('/domains/%s' % domuuid, "".encode('ascii'))
-    transaction.create('/domains/%s/state' % domuuid, "stop".encode('ascii'))
-    transaction.create('/domains/%s/hypervisor' % domuuid, socket.gethostname().encode('ascii'))
+    transaction.create('/domains/%s' % domuuid, domname.encode('ascii'))
+    transaction.create('/domains/%s/state' % domuuid, 'stop'.encode('ascii'))
+    transaction.create('/domains/%s/hypervisor' % domuuid, target_hypervisor.encode('ascii'))
     transaction.create('/domains/%s/formerhypervisor' % domuuid, ''.encode('ascii'))
+    transaction.create('/domains/%s/name' % domuuid, data.encode('ascii'))
     transaction.create('/domains/%s/xml' % domuuid, data.encode('ascii'))
     results = transaction.commit()
-    zk.stop()
-    zk.close()
+    print(results)
+    pvcf.stopZKConnection(zk)
 
-def migrate_domain(domuuid, target):
-    zk = kazoo.client.KazooClient(hosts='127.0.0.1:2181')
-    zk.start()
+def delete_domain(domuuid):
+    zk = pvcf.startZKConnection(zk_host)
+
+    # Set the domain into delete mode
+    transaction = zk.transaction()
+    transaction.set_data('/domains/%s/state' % domuuid, 'delete'.encode('ascii'))
+    results = transaction.commit()
+    print(results)
+
+    # Wait for 3 seconds to allow state to flow to all hypervisors
+    time.sleep(3)
+
+    # Delete the configurations
+    transaction = zk.transaction()
+    transaction.delete('/domains/%s/state' % domuuid)
+    transaction.delete('/domains/%s/hypervisor' % domuuid)
+    transaction.delete('/domains/%s/formerhypervisor' % domuuid)
+    transaction.delete('/domains/%s/xml' % domuuid)
+    transaction.delete('/domains/%s' % domuuid)
+    results = transaction.commit()
+    print(results)
+    pvcf.stopZKConnection(zk)
+
+# Start up a domain
+def start_domain(domuuid):
+    zk = pvcf.startZKConnection(zk_host)
+    transaction = zk.transaction()
+    transaction.set_data('/domains/%s/state' % domuuid, 'start'.encode('ascii'))
+    results = transaction.commit()
+    print(results)
+    pvcf.stopZKConnection(zk)
+
+# Shut down a domain
+def shutdown_domain(domuuid):
+    zk = pvcf.startZKConnection(zk_host)
+    transaction = zk.transaction()
+    transaction.set_data('/domains/%s/state' % domuuid, 'shutdown'.encode('ascii'))
+    results = transaction.commit()
+    print(results)
+    pvcf.stopZKConnection(zk)
+
+# Stop a domain
+def stop_domain(domuuid):
+    zk = pvcf.startZKConnection(zk_host)
+    transaction = zk.transaction()
+    transaction.set_data('/domains/%s/state' % domuuid, 'stop'.encode('ascii'))
+    results = transaction.commit()
+    print(results)
+    pvcf.stopZKConnection(zk)
+
+# Migrate VM to target_hypervisor
+def migrate_domain(domuuid, target_hypervisor):
+    zk = pvcf.startZKConnection(zk_host)
+    current_hypervisor = zk.get('/domains/%s/hypervisor' % domuuid)[0].decode('ascii')
+    former_hypervisor = zk.get('/domains/%s/formerhypervisor' % domuuid)[0].decode('ascii')
+    if former_hypervisor != '':
+        print('The VM %s has been previously migrated from %s to %s. You must unmigrate it before migrating it again!' % (domuuid, former_hypervisor, current_hypervisor))
+        pvcf.stopZKConnection(zk)
+        return
+
+    print('Migrating VM with UUID %s from hypervisor %s to hypervisor %s' % (domuuid, current_hypervisor, target_hypervisor))
     transaction = zk.transaction()
     transaction.set_data('/domains/%s/state' % domuuid, 'migrate'.encode('ascii'))
-    transaction.set_data('/domains/%s/hypervisor' % domuuid, target.encode('ascii'))
+    transaction.set_data('/domains/%s/hypervisor' % domuuid, target_hypervisor.encode('ascii'))
+    transaction.set_data('/domains/%s/formerhypervisor' % domuuid, current_hypervisor.encode('ascii'))
     results = transaction.commit()
-    zk.stop()
-    zk.close()
+    print(results)
+    pvcf.stopZKConnection(zk)
+
+# Unmigrate VM back from previous hypervisor
+def unmigrate_domain(domuuid):
+    zk = pvcf.startZKConnection(zk_host)
+    target_hypervisor = zk.get('/domains/%s/formerhypervisor' % domuuid)[0].decode('ascii')
+    if target_hypervisor == '':
+        print('The VM %s has not been previously migrated and cannot be unmigrated.' % domuuid)
+        pvcf.stopZKConnection(zk)
+        return
+    print('Unmigrating VM with UUID %s back to hypervisor %s' % (domuuid, target_hypervisor))
+    transaction = zk.transaction()
+    transaction.set_data('/domains/%s/state' % domuuid, 'migrate'.encode('ascii'))
+    transaction.set_data('/domains/%s/hypervisor' % domuuid, target_hypervisor.encode('ascii'))
+    transaction.set_data('/domains/%s/formerhypervisor' % domuuid, ''.encode('ascii'))
+    results = transaction.commit()
+    print(results)
+    pvcf.stopZKConnection(zk)
     
 
-define_domain('/var/home/joshua/debian9.xml')
+########################
+########################
+##                    ##
+##  CLICK COMPONENTS  ##
+##                    ##
+########################
+########################
+
+###############################################################################
+# pvc node
+###############################################################################
+@click.group(name='node', short_help='Manage a PVC hypervisor node', context_settings=CONTEXT_SETTINGS)
+@click.option(
+    '-n', '--name', 'node_name', default=this_host, show_default=True,
+    help='The PVC node to operate on.'
+)
+def node():
+    """
+    Manage the state of a node in the PVC cluster.
+
+    Notes:
+
+    * The '--name' option defaults to the current host if not set, which is likely not what you want when running this command from a remote host!
+    """
+    pass
+
+
+###############################################################################
+# pvc node flush
+###############################################################################
+@click.command(name='flush', short_help='Take a node out of service')
+def flush_host():
+    """
+    Take a node out of active service and migrate away all VMs.
+    """
+    pass
+
+
+###############################################################################
+# pvc node ready
+###############################################################################
+@click.command(name='ready', short_help='Restore node to service')
+def ready_host():
+    """
+    Restore a host to active service and migrate back all VMs.
+    """
+    pass
+
+
+###############################################################################
+# pvc vm
+###############################################################################
+@click.group(name='vm', short_help='Manage a PVC virtual machine', context_settings=CONTEXT_SETTINGS)
+def vm():
+    """
+    Manage the state of a virtual machine in the PVC cluster.
+
+    Notes:
+    
+    * PVC virtual machines are always managed by UUID. To find a name-to-UUID mapping, use the 'search' command.
+    """
+    pass
+
+
+###############################################################################
+# pvc vm define
+###############################################################################
+@click.command(name='define', short_help='Define a new virtual machine from a Libvirt XML file.')
+@click.option(
+    '-x', '--xml', 'xml_config_file',
+    help='The XML config file to define the domain from.'
+)
+@click.option(
+    '-v', '--hypervisor', 'target_hypervisor', default=this_host, show_default=True,
+    help='The home hypervisor for this domain.'
+)
+def define_vm(xml_config_file, target_hypervisor):
+    """
+    Define a new virtual machine from a Libvirt XML configuration file.
+
+    Notes:
+
+    * The '--hypervisor' option defaults to the current host if not set, which is likely not what you want when running this command from a remote host!
+    """
+    define_domain(xml_config_file, target_hypervisor)
+
+
+###############################################################################
+# pvc vm start
+###############################################################################
+@click.command(name='start', short_help='Start up a defined virtual machine.')
+@click.option(
+    '-n', '--name', 'dom_name',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_uuid"],
+    help='Search for this human-readable name.'
+)
+@click.option(
+    '-u', '--uuid', 'dom_uuid',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_name"],
+    help='Search for this UUID.'
+)
+def start_vm(dom_name, dom_uuid):
+    """
+    Start up a virtual machine on its configured hypervisor.
+    """
+
+    # Ensure at least one search method is set
+    if dom_name == None and dom_uuid == None:
+        click.echo("You must specify either a '--name' or '--uuid' value.")
+        return
+
+    # Open a Zookeeper connection
+    zk = pvcf.startZKConnection(zk_host)
+
+    # If the --name value was passed, get the UUID
+    if dom_name != None:
+        dom_uuid = pvcf.searchClusterByName(zk, dom_name)
+
+    # Set the VM to start
+    zk.set('/domains/%s/state' % dom_uuid, 'start'.encode('ascii'))
+
+    # Close the zookeeper connection
+    pvcf.stopZKConnection(zk)
+
+
+###############################################################################
+# pvc vm shutdown
+###############################################################################
+@click.command(name='shutdown', short_help='Gracefully shut down a running virtual machine.')
+@click.option(
+    '-n', '--name', 'dom_name',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_uuid"],
+    help='Search for this human-readable name.'
+)
+@click.option(
+    '-u', '--uuid', 'dom_uuid',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_name"],
+    help='Search for this UUID.'
+)
+def shutdown_vm(dom_name, dom_uuid):
+    """
+    Gracefully shut down a running virtual machine.
+    """
+
+    # Ensure at least one search method is set
+    if dom_name == None and dom_uuid == None:
+        click.echo("You must specify either a '--name' or '--uuid' value.")
+        return
+
+    # Open a Zookeeper connection
+    zk = pvcf.startZKConnection(zk_host)
+
+    # If the --name value was passed, get the UUID
+    if dom_name != None:
+        dom_uuid = pvcf.searchClusterByName(zk, dom_name)
+
+    # Set the VM to start
+    zk.set('/domains/%s/state' % dom_uuid, 'shutdown'.encode('ascii'))
+
+    # Close the zookeeper connection
+    pvcf.stopZKConnection(zk)
+
+
+###############################################################################
+# pvc vm stop
+###############################################################################
+@click.command(name='stop', short_help='Forcibly halt a running virtual machine.')
+@click.option(
+    '-n', '--name', 'dom_name',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_uuid"],
+    help='Search for this human-readable name.'
+)
+@click.option(
+    '-u', '--uuid', 'dom_uuid',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_name"],
+    help='Search for this UUID.'
+)
+def stop_vm(dom_name, dom_uuid):
+    """
+    Forcibly halt (destroy) a running virtual machine.
+    """
+
+    # Ensure at least one search method is set
+    if dom_name == None and dom_uuid == None:
+        click.echo("You must specify either a '--name' or '--uuid' value.")
+        return
+
+    # Open a Zookeeper connection
+    zk = pvcf.startZKConnection(zk_host)
+
+    # If the --name value was passed, get the UUID
+    if dom_name != None:
+        dom_uuid = pvcf.searchClusterByName(zk, dom_name)
+
+    # Set the VM to start
+    zk.set('/domains/%s/state' % dom_uuid, 'stop'.encode('ascii'))
+
+    # Close the zookeeper connection
+    pvcf.stopZKConnection(zk)
+
+
+@click.command(name='migrate', short_help='Migrate a virtual machine to another node.')
+def migrate_vm():
+    """
+    Migrate a running virtual machine, via live migration if possible, to another hypervisor node.
+    """
+    pass
+
+@click.command(name='unmigrate', short_help='Restore a migrated virtual machine to its original node.')
+def unmigrate_vm():
+    """
+    Restore a previously migrated virtual machine, via live migration if possible, to its original hypervisor node.
+    """
+    pass
+
+#
+# Search-level commands
+#
+@click.command(name='search', short_help='Search for a VM object')
+@click.option(
+    '-n', '--name', 'dom_name',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_uuid"],
+    help='Search for this human-readable name.'
+)
+@click.option(
+    '-u', '--uuid', 'dom_uuid',
+    cls=pvcf.MutuallyExclusiveOption,
+    mutually_exclusive=["dom_name"],
+    help='Search for this UUID.'
+)
+def search(dom_name, dom_uuid):
+    """
+    Search the cluster for a virtual machine's information.
+    """
+    zk = pvcf.startZKConnection(zk_host)
+    if dom_name != None:
+        dom_uuid = pvcf.searchClusterByName(zk, dom_name)
+    if dom_uuid != None:
+        dom_name = pvcf.searchClusterByUUID(zk, dom_uuid)
+
+    information = pvcf.getInformationFromXML(zk, dom_uuid)
+    pvcf.stopZKConnection(zk)
+
+#define_domain('/var/home/joshua/debian9.xml')
+#start_domain('b1dc4e21-544f-47aa-9bb7-8af0bc443b78')
+#stop_domain('b1dc4e21-544f-47aa-9bb7-8af0bc443b78')
 #migrate_domain('b1dc4e21-544f-47aa-9bb7-8af0bc443b78', 'test1.i.bonilan.net')
 #migrate_domain('b1dc4e21-544f-47aa-9bb7-8af0bc443b78', 'test2.i.bonilan.net')
+#unmigrate_domain('b1dc4e21-544f-47aa-9bb7-8af0bc443b78')
+
+@click.command()
+def help():
+    print('pvc - Parallel Virtual Cluster command-line utility')
+
+@click.group(context_settings=CONTEXT_SETTINGS)
+def cli():
+	"""Parallel Virtual Cluster CLI management tool"""
+	pass
+
+#
+# Click command tree
+#
+node.add_command(flush_host)
+node.add_command(ready_host)
+#node.add_command(get_details)
+
+vm.add_command(define_vm)
+vm.add_command(start_vm)
+vm.add_command(shutdown_vm)
+vm.add_command(stop_vm)
+vm.add_command(migrate_vm)
+vm.add_command(unmigrate_vm)
+#vm.add_command(get_details)
+
+cli.add_command(node)
+cli.add_command(vm)
+cli.add_command(search)
+
+#
+# Main entry point
+#
+def main():
+    return cli(obj={})
+
+if __name__ == '__main__':
+    main()
diff --git a/pvcf.py b/pvcf.py
index 0de8231d..b3984e40 100644
--- a/pvcf.py
+++ b/pvcf.py
@@ -1,6 +1,10 @@
 #!/usr/bin/env python3
 
 import os, sys, libvirt, uuid
+import kazoo.client
+import lxml
+import click
+#from click import command, option, Option, UsageError
 
 #
 # Generic function helpers for PVC
@@ -42,3 +46,118 @@ def lookupByUUID(tuuid):
     # Return the dom object (or None)
     return dom
 
+
+#
+# Connect and disconnect from Zookeeper
+#
+def startZKConnection(zk_host):
+    zk = kazoo.client.KazooClient(hosts=zk_host)
+    zk.start()
+    return zk
+
+def stopZKConnection(zk):
+    zk.stop()
+    zk.close()
+    return 0
+
+
+#
+# XML information parsing functions
+#
+def getInformationFromXML(zk, uuid):
+    # Obtain the contents of the XML from Zookeeper
+    xml = zk.get('/domains/%s/xml' % uuid)[0].decode('ascii')
+    # Parse XML using lxml.objectify
+    parsed_xml = lxml.objectify.fromstring(xml)
+    # Now get the information we want from it
+    dmemory = parsed_xml.memory
+    dmemory_unit = parsed_xml.memory.attrib['unit']
+    dcurrentMemory = parsed_xml.currentMemory
+    dcurrentMemory_unit = parsed_xml.currentMemory.attrib['unit']
+    dvcpu = parsed_xml.vcpu
+    dtype = parsed_xml.os.type
+    darch = parsed_xml.os.type.attrib['arch']
+    dmachine = parsed_xml.os.type.attrib['machine']
+    dfeatures = []
+    for feature in parsed_xml.features.getchildren():
+        dfeatures.append(feature.tag)
+    ddisks = []
+    for disk in parsed_xml.devices.disk.getchildren():
+        ddisks.append(disk.attrib)
+
+    print(ddisks)
+    return None
+
+
+
+#
+# Cluster search functions
+#
+def getClusterDomainList(zk):
+    # Get a list of UUIDs by listing the children of /domains
+    uuid_list = zk.get_children('/domains')
+    name_list = []
+    # For each UUID, get the corresponding name from the data
+    for uuid in uuid_list:
+        name_list.append(zk.get('/domains/%s' % uuid)[0].decode('ascii'))
+    return uuid_list, name_list
+
+def searchClusterByUUID(zk, uuid):
+    try:
+        # Get the lists
+        uuid_list, name_list = getClusterDomainList(zk)
+        # We're looking for UUID, so find that element ID
+        index = uuid_list.index(uuid)
+        # Get the name_list element at that index
+        name = name_list[index]
+    except ValueError:
+        # We didn't find anything
+        return None, None
+
+    return name
+
+def searchClusterByName(zk, name):
+    try:
+        # Get the lists
+        uuid_list, name_list = getClusterDomainList(zk)
+        # We're looking for name, so find that element ID
+        index = name_list.index(name)
+        # Get the uuid_list element at that index
+        uuid = uuid_list[index]
+    except ValueError:
+        # We didn't find anything
+        return None, None
+
+    return uuid
+
+
+#
+# Allow mutually exclusive options in Click
+#
+class MutuallyExclusiveOption(click.Option):
+    def __init__(self, *args, **kwargs):
+        self.mutually_exclusive = set(kwargs.pop('mutually_exclusive', []))
+        help = kwargs.get('help', '')
+        if self.mutually_exclusive:
+            ex_str = ', '.join(self.mutually_exclusive)
+            kwargs['help'] = help + (
+                ' NOTE: This argument is mutually exclusive with '
+                'arguments: [' + ex_str + '].'
+            )
+        super(MutuallyExclusiveOption, self).__init__(*args, **kwargs)
+
+    def handle_parse_result(self, ctx, opts, args):
+        if self.mutually_exclusive.intersection(opts) and self.name in opts:
+            raise click.UsageError(
+                "Illegal usage: `{}` is mutually exclusive with "
+                "arguments `{}`.".format(
+                    self.name,
+                    ', '.join(self.mutually_exclusive)
+                )
+            )
+
+        return super(MutuallyExclusiveOption, self).handle_parse_result(
+            ctx,
+            opts,
+            args
+        )