X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-web.git/blobdiff_plain/0aa4d89f6b6825785a4d95d312c86284cd5a32f8..102769b5296d5a4895fff466def7c99f8a255fb3:/templates/main.py

diff --git a/templates/main.py b/templates/main.py
index 36518d6..cc8c3d8 100755
--- a/templates/main.py
+++ b/templates/main.py
@@ -1,167 +1,117 @@
 #!/usr/bin/python
+"""Main CGI script for web interface"""
 
-import sys
+import base64
+import cPickle
 import cgi
+import datetime
+import hmac
 import os
-import string
-import subprocess
-import re
-import time
-import cPickle
-import base64
 import sha
-import hmac
-import datetime
-
-print 'Content-Type: text/html\n'
-sys.stderr = sys.stdout
-sys.path.append('/home/ecprice/.local/lib/python2.5/site-packages')
-
-from Cheetah.Template import Template
-from sipb_xen_database import *
-import random
-
-class MyException(Exception):
-    pass
-
-# ... and stolen from xend/uuid.py
-def randomUUID():
-    """Generate a random UUID."""
-
-    return [ random.randint(0, 255) for _ in range(0, 16) ]
-
-def uuidToString(u):
-    return "-".join(["%02x" * 4, "%02x" * 2, "%02x" * 2, "%02x" * 2,
-                     "%02x" * 6]) % tuple(u)
-
-def maxMemory(user, machine=None):
-    return 256
-
-def maxDisk(user, machine=None):
-    return 10.0
-
-def haveAccess(user, machine):
-    return True
-
-def error(op, user, fields, err):
-    d = dict(op=op, user=user, errorMessage=str(err))
-    print Template(file='error.tmpl', searchList=d);
+import simplejson
+import sys
+import time
+from StringIO import StringIO
 
-def validMachineName(name):
-    """Check that name is valid for a machine name"""
-    if not name:
-        return False
-    charset = string.ascii_letters + string.digits + '-_'
-    if name[0] in '-_' or len(name) > 22:
-        return False
-    return all(x in charset for x in name)
 
-def kinit(username = 'tabbott/extra', keytab = '/etc/tabbott.keytab'):
-    """Kinit with a given username and keytab"""
+def revertStandardError():
+    """Move stderr to stdout, and return the contents of the old stderr."""
+    errio = sys.stderr
+    if not isinstance(errio, StringIO):
+        return None
+    sys.stderr = sys.stdout
+    errio.seek(0)
+    return errio.read()
 
-    p = subprocess.Popen(['kinit', "-k", "-t", keytab, username],
-                         stderr=subprocess.PIPE)
-    e = p.wait()
-    if e:
-        raise MyException("Error %s in kinit: %s" % (e, p.stderr.read()))
+def printError():
+    """Revert stderr to stdout, and print the contents of stderr"""
+    if isinstance(sys.stderr, StringIO):
+        print revertStandardError()
 
-def checkKinit():
-    """If we lack tickets, kinit."""
-    p = subprocess.Popen(['klist', '-s'])
-    if p.wait():
-        kinit()
+if __name__ == '__main__':
+    import atexit
+    atexit.register(printError)
+    sys.stderr = StringIO()
 
-def remctl(*args, **kws):
-    """Perform a remctl and return the output.
+sys.path.append('/home/ecprice/.local/lib/python2.5/site-packages')
 
-    kinits if necessary, and outputs errors to stderr.
-    """
-    checkKinit()
-    p = subprocess.Popen(['remctl', 'black-mesa.mit.edu']
-                         + list(args),
-                         stdout=subprocess.PIPE,
-                         stderr=subprocess.PIPE)
-    if kws.get('err'):
-        return p.stdout.read(), p.stderr.read()
-    if p.wait():
-        print >> sys.stderr, 'ERROR on remctl ', args
-        print >> sys.stderr, p.stderr.read()
-    return p.stdout.read()
-
-def makeDisks():
-    """Update the lvm partitions to include all disks in the database."""
-    remctl('web', 'lvcreate')
-
-def bootMachine(machine, cdtype):
-    """Boot a machine with a given boot CD.
-
-    If cdtype is None, give no boot cd.  Otherwise, it is the string
-    id of the CD (e.g. 'gutsy_i386')
-    """
-    if cdtype is not None:
-        remctl('web', 'vmboot', machine.name,
-               cdtype)
+from Cheetah.Template import Template
+from sipb_xen_database import Machine, CDROM, ctx, connect
+import validation
+from webcommon import InvalidInput, CodeError, g
+import controls
+
+def helppopup(subj):
+    """Return HTML code for a (?) link to a specified help topic"""
+    return ('<span class="helplink"><a href="help?subject=' + subj + 
+            '&amp;simple=true" target="_blank" ' + 
+            'onclick="return helppopup(\'' + subj + '\')">(?)</a></span>')
+
+class User:
+    """User class (sort of useless, I admit)"""
+    def __init__(self, username, email):
+        self.username = username
+        self.email = email
+
+def makeErrorPre(old, addition):
+    if addition is None:
+        return
+    if old:
+        return old[:-6]  + '\n----\n' + str(addition) + '</pre>'
     else:
-        remctl('web', 'vmboot', machine.name)
-
-def registerMachine(machine):
-    """Register a machine to be controlled by the web interface"""
-    remctl('web', 'register', machine.name)
-
-def unregisterMachine(machine):
-    """Unregister a machine to not be controlled by the web interface"""
-    remctl('web', 'unregister', machine.name)
-
-def parseStatus(s):
-    """Parse a status string into nested tuples of strings.
-
-    s = output of xm list --long <machine_name>
-    """
-    values = re.split('([()])', s)
-    stack = [[]]
-    for v in values[2:-2]: #remove initial and final '()'
-        if not v:
-            continue
-        v = v.strip()
-        if v == '(':
-            stack.append([])
-        elif v == ')':
-            if len(stack[-1]) == 1:
-                stack[-1].append('')
-            stack[-2].append(stack[-1])
-            stack.pop()
-        else:
-            if not v:
-                continue
-            stack[-1].extend(v.split())
-    return stack[-1]
-
-def getUptimes(machines):
-    """Return a dictionary mapping machine names to uptime strings"""
-    value_string = remctl('web', 'listvms')
-    lines = value_string.splitlines()
-    d = {}
-    for line in lines[1:]:
-        lst = line.split()
-        name, id = lst[:2]
-        uptime = ' '.join(lst[2:])
-        d[name] = uptime
-    return d
-
-def statusInfo(machine):
-    """Return the status list for a given machine.
-
-    Gets and parses xm list --long
-    """
-    value_string, err_string = remctl('list-long', machine.name, err=True)
-    if 'Unknown command' in err_string:
-        raise MyException("ERROR in remctl list-long %s is not registered" % (machine.name,))
-    elif 'does not exist' in err_string:
-        return None
-    elif err_string:
-        raise MyException("ERROR in remctl list-long %s:  %s" % (machine.name, err_string))
-    status = parseStatus(value_string)
-    return status
+        return '<p>STDERR:</p><pre>' + str(addition) + '</pre>'
+
+Template.helppopup = staticmethod(helppopup)
+Template.err = None
+
+class JsonDict:
+    """Class to store a dictionary that will be converted to JSON"""
+    def __init__(self, **kws):
+        self.data = kws
+        if 'err' in kws:
+            err = kws['err']
+            del kws['err']
+            self.addError(err)
+
+    def __str__(self):
+        return simplejson.dumps(self.data)
+
+    def addError(self, text):
+        """Add stderr text to be displayed on the website."""
+        self.data['err'] = \
+            makeErrorPre(self.data.get('err'), text)
+
+class Defaults:
+    """Class to store default values for fields."""
+    memory = 256
+    disk = 4.0
+    cdrom = ''
+    name = ''
+    vmtype = 'hvm'
+    def __init__(self, max_memory=None, max_disk=None, **kws):
+        if max_memory is not None:
+            self.memory = min(self.memory, max_memory)
+        if max_disk is not None:
+            self.max_disk = min(self.disk, max_disk)
+        for key in kws:
+            setattr(self, key, kws[key])
+
+
+
+DEFAULT_HEADERS = {'Content-Type': 'text/html'}
+
+def error(op, user, fields, err, emsg):
+    """Print an error page when a CodeError occurs"""
+    d = dict(op=op, user=user, errorMessage=str(err),
+             stderr=emsg)
+    return Template(file='error.tmpl', searchList=[d])
+
+def invalidInput(op, user, fields, err, emsg):
+    """Print an error page when an InvalidInput exception occurs"""
+    d = dict(op=op, user=user, err_field=err.err_field,
+             err_value=str(err.err_value), stderr=emsg,
+             errorMessage=str(err))
+    return Template(file='invalid.tmpl', searchList=[d])
 
 def hasVnc(status):
     """Does the machine with a given status list support VNC?"""
@@ -173,133 +123,88 @@ def hasVnc(status):
             return 'location' in d
     return False
 
-def createVm(user, name, memory, disk, is_hvm, cdrom):
-    """Create a VM and put it in the database"""
-    # put stuff in the table
-    transaction = ctx.current.create_transaction()
-    try:
-        res = meta.engine.execute('select nextval(\'"machines_machine_id_seq"\')')
-        id = res.fetchone()[0]
-        machine = Machine()
-        machine.machine_id = id
-        machine.name = name
-        machine.memory = memory
-        machine.owner = user.username
-        machine.contact = user.email
-        machine.uuid = uuidToString(randomUUID())
-        machine.boot_off_cd = True
-        machine_type = Type.get_by(hvm=is_hvm)
-        machine.type_id = machine_type.type_id
-        ctx.current.save(machine)
-        disk = Disk(machine.machine_id, 
-                    'hda', disk)
-        open = NIC.select_by(machine_id=None)
-        if not open: #No IPs left!
-            return "No IP addresses left!  Contact sipb-xen-dev@mit.edu"
-        nic = open[0]
-        nic.machine_id = machine.machine_id
-        nic.hostname = name
-        ctx.current.save(nic)    
-        ctx.current.save(disk)
-        transaction.commit()
-    except:
-        transaction.rollback()
-        raise
-    makeDisks()
-    registerMachine(machine)
-    # tell it to boot with cdrom
-    bootMachine(machine, cdrom)
-
-    return machine
-
-def validMemory(user, memory, machine=None):
-    try:
-        memory = int(memory)
-        if memory <= 0:
-            raise ValueError
-    except ValueError:
-        raise MyException("Invalid memory amount")
-    if memory > maxMemory(user, machine):
-        raise MyException("Too much memory requested")
-    return memory
-
-def validDisk(user, disk, machine=None):
-    try:
-        disk = float(disk)
-        if disk > maxDisk(user, machine):
-            raise MyException("Too much disk requested")
-        disk = int(disk * 1024)
-        if disk <= 0:
-            raise ValueError
-    except ValueError:
-        raise MyException("Invalid disk amount")
-    return disk
-
-def create(user, fields):
+def parseCreate(user, fields):
     name = fields.getfirst('name')
-    if not validMachineName(name):
-        raise MyException("Invalid name '%s'" % name)
-    name = user.username + '_' + name.lower()
+    if not validation.validMachineName(name):
+        raise InvalidInput('name', name, 'You must provide a machine name.')
+    name = name.lower()
 
     if Machine.get_by(name=name):
-        raise MyException("A machine named '%s' already exists" % name)
+        raise InvalidInput('name', name,
+                           "Name already exists.")
     
     memory = fields.getfirst('memory')
-    memory = validMemory(user, memory)
+    memory = validation.validMemory(user, memory, on=True)
     
     disk = fields.getfirst('disk')
-    disk = validDisk(user, disk)
+    disk = validation.validDisk(user, disk)
 
     vm_type = fields.getfirst('vmtype')
     if vm_type not in ('hvm', 'paravm'):
-        raise MyException("Invalid vm type '%s'"  % vm_type)    
+        raise CodeError("Invalid vm type '%s'"  % vm_type)    
     is_hvm = (vm_type == 'hvm')
 
     cdrom = fields.getfirst('cdrom')
     if cdrom is not None and not CDROM.get(cdrom):
-        raise MyException("Invalid cdrom type '%s'" % cdrom)    
-    
-    machine = createVm(user, name, memory, disk, is_hvm, cdrom)
-    if isinstance(machine, basestring):
-        raise MyException(machine)
-    d = dict(user=user,
-             machine=machine)
-    print Template(file='create.tmpl',
-                   searchList=d);
+        raise CodeError("Invalid cdrom type '%s'" % cdrom)
+    return dict(user=user, name=name, memory=memory, disk=disk,
+                is_hvm=is_hvm, cdrom=cdrom)
 
-def listVms(user, fields):
-    machines = Machine.select()
+def create(user, fields):
+    """Handler for create requests."""
+    try:
+        parsed_fields = parseCreate(user, fields)
+        machine = controls.createVm(**parsed_fields)
+    except InvalidInput, err:
+        pass
+    else:
+        err = None
+    g.clear() #Changed global state
+    d = getListDict(user)
+    d['err'] = err
+    if err:
+        for field in fields.keys():
+            setattr(d['defaults'], field, fields.getfirst(field))
+    else:
+        d['new_machine'] = parsed_fields['name']
+    return Template(file='list.tmpl', searchList=[d])
+
+
+def getListDict(user):
+    machines = [m for m in Machine.select() 
+                if validation.haveAccess(user, m)]    
     on = {}
     has_vnc = {}
-    uptimes = getUptimes(machines)
-    on = has_vnc = uptimes
-    #     for m in machines:
-    #         status = statusInfo(m)
-    #         on[m.name] = status is not None
-    #         has_vnc[m.name] = hasVnc(status)
+    on = g.uptimes
+    for m in machines:
+        m.uptime = g.uptimes.get(m)
+        if not on[m]:
+            has_vnc[m] = 'Off'
+        elif m.type.hvm:
+            has_vnc[m] = True
+        else:
+            has_vnc[m] = "ParaVM"+helppopup("paravm_console")
+    max_memory = validation.maxMemory(user)
+    max_disk = validation.maxDisk(user)
+    defaults = Defaults(max_memory=max_memory,
+                        max_disk=max_disk,
+                        cdrom='gutsy-i386')
     d = dict(user=user,
-             maxmem=maxMemory(user),
-             maxdisk=maxDisk(user),
+             cant_add_vm=validation.cantAddVm(user),
+             max_memory=max_memory,
+             max_disk=max_disk,
+             defaults=defaults,
              machines=machines,
              has_vnc=has_vnc,
-             uptimes=uptimes,
+             uptimes=g.uptimes,
              cdroms=CDROM.select())
-    print Template(file='list.tmpl', searchList=d)
-
-def testMachineId(user, machineId, exists=True):
-    if machineId is None:
-        raise MyException("No machine ID specified")
-    try:
-        machineId = int(machineId)
-    except ValueError:
-        raise MyException("Invalid machine ID '%s'" % machineId)
-    machine = Machine.get(machineId)
-    if exists and machine is None:
-        raise MyException("No such machine ID '%s'" % machineId)
-    if not haveAccess(user, machine):
-        raise MyException("No access to machine ID '%s'" % machineId)
-    return machine
+    return d
 
+def listVms(user, fields):
+    """Handler for list requests."""
+    d = getListDict(user)
+    return Template(file='list.tmpl', searchList=[d])
+            
 def vnc(user, fields):
     """VNC applet page.
 
@@ -310,34 +215,48 @@ def vnc(user, fields):
 
     You might want iptables like:
 
-    -t nat -A PREROUTING -s ! 18.181.0.60 -i eth1 -p tcp -m tcp --dport 10003 -j DNAT --to-destination 18.181.0.60:10003 
-    -t nat -A POSTROUTING -d 18.181.0.60 -o eth1 -p tcp -m tcp --dport 10003 -j SNAT --to-source 18.187.7.142 
-    -A FORWARD -d 18.181.0.60 -i eth1 -o eth1 -p tcp -m tcp --dport 10003 -j ACCEPT
+    -t nat -A PREROUTING -s ! 18.181.0.60 -i eth1 -p tcp -m tcp \
+      --dport 10003 -j DNAT --to-destination 18.181.0.60:10003 
+    -t nat -A POSTROUTING -d 18.181.0.60 -o eth1 -p tcp -m tcp \
+      --dport 10003 -j SNAT --to-source 18.187.7.142 
+    -A FORWARD -d 18.181.0.60 -i eth1 -o eth1 -p tcp -m tcp \
+      --dport 10003 -j ACCEPT
+
+    Remember to enable iptables!
+    echo 1 > /proc/sys/net/ipv4/ip_forward
     """
-    machine = testMachineId(user, fields.getfirst('machine_id'))
-    #XXX fix
+    machine = validation.testMachineId(user, fields.getfirst('machine_id'))
     
     TOKEN_KEY = "0M6W0U1IXexThi5idy8mnkqPKEq1LtEnlK/pZSn0cDrN"
 
     data = {}
     data["user"] = user.username
-    data["machine"]=machine.name
-    data["expires"]=time.time()+(5*60)
-    pickledData = cPickle.dumps(data)
+    data["machine"] = machine.name
+    data["expires"] = time.time()+(5*60)
+    pickled_data = cPickle.dumps(data)
     m = hmac.new(TOKEN_KEY, digestmod=sha)
-    m.update(pickledData)
-    token = {'data': pickledData, 'digest': m.digest()}
+    m.update(pickled_data)
+    token = {'data': pickled_data, 'digest': m.digest()}
     token = cPickle.dumps(token)
     token = base64.urlsafe_b64encode(token)
     
+    status = controls.statusInfo(machine)
+    has_vnc = hasVnc(status)
+    
     d = dict(user=user,
+             on=status,
+             has_vnc=has_vnc,
              machine=machine,
              hostname=os.environ.get('SERVER_NAME', 'localhost'),
              authtoken=token)
-    print Template(file='vnc.tmpl',
-                   searchList=d)
+    return Template(file='vnc.tmpl', searchList=[d])
 
 def getNicInfo(data_dict, machine):
+    """Helper function for info, get data on nics for a machine.
+
+    Modifies data_dict to include the relevant data, and returns a list
+    of (key, name) pairs to display "name: data_dict[key]" to the user.
+    """
     data_dict['num_nics'] = len(machine.nics)
     nic_fields_template = [('nic%s_hostname', 'NIC %s hostname'),
                            ('nic%s_mac', 'NIC %s MAC Addr'),
@@ -346,7 +265,8 @@ def getNicInfo(data_dict, machine):
     nic_fields = []
     for i in range(len(machine.nics)):
         nic_fields.extend([(x % i, y % i) for x, y in nic_fields_template])
-        data_dict['nic%s_hostname' % i] = machine.nics[i].hostname + '.servers.csail.mit.edu'
+        data_dict['nic%s_hostname' % i] = (machine.nics[i].hostname + 
+                                           '.servers.csail.mit.edu')
         data_dict['nic%s_mac' % i] = machine.nics[i].mac_addr
         data_dict['nic%s_ip' % i] = machine.nics[i].ip
     if len(machine.nics) == 1:
@@ -354,93 +274,203 @@ def getNicInfo(data_dict, machine):
     return nic_fields
 
 def getDiskInfo(data_dict, machine):
+    """Helper function for info, get data on disks for a machine.
+
+    Modifies data_dict to include the relevant data, and returns a list
+    of (key, name) pairs to display "name: data_dict[key]" to the user.
+    """
     data_dict['num_disks'] = len(machine.disks)
     disk_fields_template = [('%s_size', '%s size')]
     disk_fields = []
     for disk in machine.disks:
         name = disk.guest_device_name
-        disk_fields.extend([(x % name, y % name) for x, y in disk_fields_template])
-        data_dict['%s_size' % name] = "%0.1f GB" % (disk.size / 1024.)
+        disk_fields.extend([(x % name, y % name) for x, y in 
+                            disk_fields_template])
+        data_dict['%s_size' % name] = "%0.1f GiB" % (disk.size / 1024.)
     return disk_fields
 
-def deleteVM(machine):
+def command(user, fields):
+    """Handler for running commands like boot and delete on a VM."""
+    back = fields.getfirst('back')
+    try:
+        d = controls.commandResult(user, fields)
+        if d['command'] == 'Delete VM':
+            back = 'list'
+    except InvalidInput, err:
+        if not back:
+            raise
+        print >> sys.stderr, err
+        result = None
+    else:
+        result = 'Success!'
+        if not back:
+            return Template(file='command.tmpl', searchList=[d])
+    if back == 'list':
+        g.clear() #Changed global state
+        d = getListDict(user)
+        d['result'] = result
+        return Template(file='list.tmpl', searchList=[d])
+    elif back == 'info':
+        machine = validation.testMachineId(user, fields.getfirst('machine_id'))
+        d = infoDict(user, machine)
+        d['result'] = result
+        return Template(file='info.tmpl', searchList=[d])
+    else:
+        raise InvalidInput('back', back, 'Not a known back page.')
+
+def modifyDict(user, fields):
+    olddisk = {}
     transaction = ctx.current.create_transaction()
-    delete_disk_pairs = [(machine.name, d.guest_device_name) for d in machine.disks]
     try:
-        for nic in machine.nics:
-            nic.machine_id = None
-            nic.hostname = None
+        machine = validation.testMachineId(user, fields.getfirst('machine_id'))
+        owner = validation.testOwner(user, fields.getfirst('owner'), machine)
+        admin = validation.testAdmin(user, fields.getfirst('administrator'),
+                                     machine)
+        contact = validation.testContact(user, fields.getfirst('contact'),
+                                         machine)
+        hostname = validation.testHostname(owner, fields.getfirst('hostname'),
+                                           machine)
+        name = validation.testName(user, fields.getfirst('name'), machine)
+        oldname = machine.name
+        command = "modify"
+
+        memory = fields.getfirst('memory')
+        if memory is not None:
+            memory = validation.validMemory(user, memory, machine, on=False)
+            machine.memory = memory
+ 
+        disksize = validation.testDisk(user, fields.getfirst('disk'))
+        if disksize is not None:
+            disksize = validation.validDisk(user, disksize, machine)
+            disk = machine.disks[0]
+            if disk.size != disksize:
+                olddisk[disk.guest_device_name] = disksize
+                disk.size = disksize
+                ctx.current.save(disk)
+        
+        # XXX first NIC gets hostname on change?  
+        # Interface doesn't support more.
+        for nic in machine.nics[:1]:
+            nic.hostname = hostname
             ctx.current.save(nic)
-        for disk in machine.disks:
-            ctx.current.delete(disk)
-        ctx.current.delete(machine)
+
+        if owner is not None:
+            machine.owner = owner
+        if name is not None:
+            machine.name = name
+        if admin is not None:
+            machine.administrator = admin
+        if contact is not None:
+            machine.contact = contact
+            
+        ctx.current.save(machine)
         transaction.commit()
     except:
         transaction.rollback()
         raise
-    for mname, dname in delete_disk_pairs:
-        remctl('web', 'lvremove', mname, dname)
-    unregisterMachine(machine)
-
-def command(user, fields):
-    print time.time()-start_time
-    machine = testMachineId(user, fields.getfirst('machine_id'))
-    action = fields.getfirst('action')
-    cdrom = fields.getfirst('cdrom')
-    print time.time()-start_time
-    if cdrom is not None and not CDROM.get(cdrom):
-        raise MyException("Invalid cdrom type '%s'" % cdrom)    
-    if action not in ('Reboot', 'Power on', 'Power off', 'Shutdown', 'Delete VM'):
-        raise MyException("Invalid action '%s'" % action)
-    if action == 'Reboot':
-        if cdrom is not None:
-            remctl('reboot', machine.name, cdrom)
-        else:
-            remctl('reboot', machine.name)
-    elif action == 'Power on':
-        bootMachine(machine, cdrom)
-    elif action == 'Power off':
-        remctl('destroy', machine.name)
-    elif action == 'Shutdown':
-        remctl('shutdown', machine.name)
-    elif action == 'Delete VM':
-        deleteVM(machine)
-    print time.time()-start_time
+    for diskname in olddisk:
+        controls.resizeDisk(oldname, diskname, str(olddisk[diskname]))
+    if name is not None:
+        controls.renameMachine(machine, oldname, name)
+    return dict(user=user,
+                command=command,
+                machine=machine)
+    
+def modify(user, fields):
+    """Handler for modifying attributes of a machine."""
+    try:
+        modify_dict = modifyDict(user, fields)
+    except InvalidInput, err:
+        result = None
+        machine = validation.testMachineId(user, fields.getfirst('machine_id'))
+    else:
+        machine = modify_dict['machine']
+        result = 'Success!'
+        err = None
+    info_dict = infoDict(user, machine)
+    info_dict['err'] = err
+    if err:
+        for field in fields.keys():
+            setattr(info_dict['defaults'], field, fields.getfirst(field))
+    info_dict['result'] = result
+    return Template(file='info.tmpl', searchList=[info_dict])
+    
 
-    d = dict(user=user,
-             command=action,
-             machine=machine)
-    print Template(file="command.tmpl", searchList=d)
+def helpHandler(user, fields):
+    """Handler for help messages."""
+    simple = fields.getfirst('simple')
+    subjects = fields.getlist('subject')
+    
+    help_mapping = dict(paravm_console="""
+ParaVM machines do not support console access over VNC.  To access
+these machines, you either need to boot with a liveCD and ssh in or
+hope that the sipb-xen maintainers add support for serial consoles.""",
+                        hvm_paravm="""
+HVM machines use the virtualization features of the processor, while
+ParaVM machines use Xen's emulation of virtualization features.  You
+want an HVM virtualized machine.""",
+                        cpu_weight="""
+Don't ask us!  We're as mystified as you are.""",
+                        owner="""
+The owner field is used to determine <a
+href="help?subject=quotas">quotas</a>.  It must be the name of a
+locker that you are an AFS administrator of.  In particular, you or an
+AFS group you are a member of must have AFS rlidwka bits on the
+locker.  You can check see who administers the LOCKER locker using the
+command 'fs la /mit/LOCKER' on Athena.)  See also <a
+href="help?subject=administrator">administrator</a>.""",
+                        administrator="""
+The administrator field determines who can access the console and
+power on and off the machine.  This can be either a user or a moira
+group.""",
+                        quotas="""
+Quotas are determined on a per-locker basis.  Each quota may have a
+maximum of 512 megabytes of active ram, 50 gigabytes of disk, and 4
+active machines."""
+                   )
+    
+    if not subjects:
+        subjects = sorted(help_mapping.keys())
         
-def modify(user, fields):
-    machine = testMachineId(user, fields.getfirst('machine_id'))
+    d = dict(user=user,
+             simple=simple,
+             subjects=subjects,
+             mapping=help_mapping)
+    
+    return Template(file="help.tmpl", searchList=[d])
     
 
-def info(user, fields):
-    machine = testMachineId(user, fields.getfirst('machine_id'))
-    status = statusInfo(machine)
+def badOperation(u, e):
+    raise CodeError("Unknown operation")
+
+def infoDict(user, machine):
+    status = controls.statusInfo(machine)
     has_vnc = hasVnc(status)
     if status is None:
         main_status = dict(name=machine.name,
                            memory=str(machine.memory))
+        uptime = None
+        cputime = None
     else:
         main_status = dict(status[1:])
-    start_time = float(main_status.get('start_time', 0))
-    uptime = datetime.timedelta(seconds=int(time.time()-start_time))
-    cpu_time_float = float(main_status.get('cpu_time', 0))
-    cputime = datetime.timedelta(seconds=int(cpu_time_float))
+        start_time = float(main_status.get('start_time', 0))
+        uptime = datetime.timedelta(seconds=int(time.time()-start_time))
+        cpu_time_float = float(main_status.get('cpu_time', 0))
+        cputime = datetime.timedelta(seconds=int(cpu_time_float))
     display_fields = """name uptime memory state cpu_weight on_reboot 
      on_poweroff on_crash on_xend_start on_xend_stop bootloader""".split()
     display_fields = [('name', 'Name'),
                       ('owner', 'Owner'),
+                      ('administrator', 'Administrator'),
                       ('contact', 'Contact'),
+                      ('type', 'Type'),
                       'NIC_INFO',
                       ('uptime', 'uptime'),
                       ('cputime', 'CPU usage'),
                       ('memory', 'RAM'),
                       'DISK_INFO',
                       ('state', 'state (xen format)'),
-                      ('cpu_weight', 'CPU weight'),
+                      ('cpu_weight', 'CPU weight'+helppopup('cpu_weight')),
                       ('on_reboot', 'Action on VM reboot'),
                       ('on_poweroff', 'Action on VM poweroff'),
                       ('on_crash', 'Action on VM crash'),
@@ -450,72 +480,137 @@ def info(user, fields):
                       ]
     fields = []
     machine_info = {}
+    machine_info['name'] = machine.name
+    machine_info['type'] = machine.type.hvm and 'HVM' or 'ParaVM'
     machine_info['owner'] = machine.owner
+    machine_info['administrator'] = machine.administrator
     machine_info['contact'] = machine.contact
 
     nic_fields = getNicInfo(machine_info, machine)
     nic_point = display_fields.index('NIC_INFO')
-    display_fields = display_fields[:nic_point] + nic_fields + display_fields[nic_point+1:]
+    display_fields = (display_fields[:nic_point] + nic_fields + 
+                      display_fields[nic_point+1:])
 
     disk_fields = getDiskInfo(machine_info, machine)
     disk_point = display_fields.index('DISK_INFO')
-    display_fields = display_fields[:disk_point] + disk_fields + display_fields[disk_point+1:]
+    display_fields = (display_fields[:disk_point] + disk_fields + 
+                      display_fields[disk_point+1:])
     
-    main_status['memory'] += ' MB'
+    main_status['memory'] += ' MiB'
     for field, disp in display_fields:
-        if field in ('uptime', 'cputime'):
+        if field in ('uptime', 'cputime') and locals()[field] is not None:
             fields.append((disp, locals()[field]))
-        elif field in main_status:
-            fields.append((disp, main_status[field]))
         elif field in machine_info:
             fields.append((disp, machine_info[field]))
+        elif field in main_status:
+            fields.append((disp, main_status[field]))
         else:
             pass
             #fields.append((disp, None))
-
+    max_mem = validation.maxMemory(user, machine)
+    max_disk = validation.maxDisk(user, machine)
+    defaults = Defaults()
+    for name in 'machine_id name administrator owner memory contact'.split():
+        setattr(defaults, name, getattr(machine, name))
+    if machine.nics:
+        defaults.hostname = machine.nics[0].hostname
+    defaults.disk = "%0.2f" % (machine.disks[0].size/1024.)
     d = dict(user=user,
              cdroms=CDROM.select(),
              on=status is not None,
              machine=machine,
+             defaults=defaults,
              has_vnc=has_vnc,
              uptime=str(uptime),
              ram=machine.memory,
-             maxmem=maxMemory(user, machine),
-             maxdisk=maxDisk(user, machine),
+             max_mem=max_mem,
+             max_disk=max_disk,
+             owner_help=helppopup("owner"),
              fields = fields)
-    print Template(file='info.tmpl',
-                   searchList=d)
+    return d
+
+def info(user, fields):
+    """Handler for info on a single VM."""
+    machine = validation.testMachineId(user, fields.getfirst('machine_id'))
+    d = infoDict(user, machine)
+    return Template(file='info.tmpl', searchList=[d])
 
 mapping = dict(list=listVms,
                vnc=vnc,
                command=command,
                modify=modify,
                info=info,
-               create=create)
+               create=create,
+               help=helpHandler)
+
+def printHeaders(headers):
+    for key, value in headers.iteritems():
+        print '%s: %s' % (key, value)
+    print
+
+
+def getUser():
+    """Return the current user based on the SSL environment variables"""
+    if 'SSL_CLIENT_S_DN_Email' in os.environ:
+        username = os.environ['SSL_CLIENT_S_DN_Email'].split("@")[0]
+        return User(username, os.environ['SSL_CLIENT_S_DN_Email'])
+    else:
+        return User('moo', 'nobody')
+
+def main(operation, user, fields):    
+    fun = mapping.get(operation, badOperation)
+
+    if fun not in (helpHandler, ):
+        connect('postgres://sipb-xen@sipb-xen-dev.mit.edu/sipb_xen')
+    try:
+        output = fun(u, fields)
+
+        headers = dict(DEFAULT_HEADERS)
+        if isinstance(output, tuple):
+            new_headers, output = output
+            headers.update(new_headers)
+
+        e = revertStandardError()
+        if e:
+            output.addError(e)
+        printHeaders(headers)
+        print output
+    except Exception, err:
+        if not fields.has_key('js'):
+            if isinstance(err, CodeError):
+                print 'Content-Type: text/html\n'
+                e = revertStandardError()
+                print error(operation, u, fields, err, e)
+                sys.exit(1)
+            if isinstance(err, InvalidInput):
+                print 'Content-Type: text/html\n'
+                e = revertStandardError()
+                print invalidInput(operation, u, fields, err, e)
+                sys.exit(1)
+        print 'Content-Type: text/plain\n'
+        print 'Uh-oh!  We experienced an error.'
+        print 'Please email sipb-xen@mit.edu with the contents of this page.'
+        print '----'
+        e = revertStandardError()
+        print e
+        print '----'
+        raise
 
 if __name__ == '__main__':
     start_time = time.time()
     fields = cgi.FieldStorage()
-    class User:
-        username = "moo"
-        email = 'moo@cow.com'
-    u = User()
-    connect('postgres://sipb-xen@sipb-xen-dev/sipb_xen')
+    u = getUser()
+    g.user = u
     operation = os.environ.get('PATH_INFO', '')
     if not operation:
-        pass
-        #XXX do redirect
+        print "Status: 301 Moved Permanently"
+        print 'Location: ' + os.environ['SCRIPT_NAME']+'/\n'
+        sys.exit(0)
 
     if operation.startswith('/'):
         operation = operation[1:]
     if not operation:
         operation = 'list'
-    
-    fun = mapping.get(operation, 
-                      lambda u, e:
-                          error(operation, u, e,
-                                "Invalid operation '%s'" % operation))
-    try:
-        fun(u, fields)
-    except MyException, err:
-        error(operation, u, fields, err)
+
+    main(operation, u, fields)
+