Changeset 145

Timestamp:

Oct 8, 2007, 7:17:34 AM (17 years ago)

Author:

ecprice

Message:

Documentation + cleaning up a little.

File:

• trunk/web/templates/main.py (modified) (27 diffs)

trunk/web/templates/main.py

@@ -22 +22 @@
 
 class MyException(Exception):
+    """Base class for my exceptions"""
     pass
 
+class InvalidInput(MyException):
+    """Exception for user-provided input is invalid but maybe in good faith.
+
+    This would include setting memory to negative (which might be a
+    typo) but not setting an invalid boot CD (which requires bypassing
+    the select box).
+    """
+    pass
+
+class CodeError(MyException):
+    """Exception for internal errors or bad faith input."""
+    pass
+
+
+
 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>'
 
@@ -39 +56 @@
 
 def uuidToString(u):
+    """Turn a numeric UUID to a hyphen-seperated one."""
     return "-".join(["%02x" * 4, "%02x" * 2, "%02x" * 2, "%02x" * 2,
                      "%02x" * 6]) % tuple(u)
@@ -51 +69 @@
 MAX_VMS_ACTIVE = 4
 
-def getMachinesOwner(owner):
+def getMachinesByOwner(owner):
+    """Return the machines owned by a given owner."""
     return Machine.select_by(owner=owner)
 
 def maxMemory(user, machine=None, on=None):
-    machines = getMachinesOwner(user.username)
+    """Return the maximum memory for a machine or a user.
+
+    If machine is None, return the memory available for a new 
+    machine.  Else, return the maximum that machine can have.
+
+    on is a dictionary from machines to booleans, whether a machine is
+    on.  If None, it is recomputed. XXX make this global?
+    """
+
+    machines = getMachinesByOwner(user.username)
     if on is None:
         on = getUptimes(machines)
@@ -63 +91 @@
 
 def maxDisk(user, machine=None):
-    machines = getMachinesOwner(user.username)
+    machines = getMachinesByOwner(user.username)
     disk_usage = sum([sum([y.size for y in x.disks])
                       for x in machines if x != machine])
@@ -69 +97 @@
 
 def canAddVm(user, on=None):
-    machines = getMachinesOwner(user.username)
+    machines = getMachinesByOwner(user.username)
     if on is None:
         on = getUptimes(machines)
@@ -77 +105 @@
 
 def haveAccess(user, machine):
+    """Return whether a user has access to a machine"""
     if user.username == 'moo':
         return True
@@ -82 +111 @@
 
 def error(op, user, fields, err):
+    """Print an error page when a CodeError occurs"""
     d = dict(op=op, user=user, errorMessage=str(err))
     print Template(file='error.tmpl', searchList=[d, global_dict]);
@@ -104 +134 @@
     e = p.wait()
     if e:
-        raise MyException("Error %s in kinit: %s" % (e, p.stderr.read()))
+        raise CodeError("Error %s in kinit: %s" % (e, p.stderr.read()))
 
 def checkKinit():
@@ -126 +156 @@
         return p.stdout.read(), p.stderr.read()
     if p.wait():
-        raise MyException('ERROR on remctl %s: %s' %
+        raise CodeError('ERROR on remctl %s: %s' %
                           (args, p.stderr.read()))
     return p.stdout.read()
@@ -200 +230 @@
     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,))
+        raise CodeError("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))
+        raise CodeError("ERROR in remctl list-long %s:  %s" % (machine.name, err_string))
     status = parseStatus(value_string)
     return status
@@ -224 +254 @@
     try:
         if memory > maxMemory(user):
-            raise MyException("Too much memory requested")
+            raise InvalidInput("Too much memory requested")
         if disk > maxDisk(user) * 1024:
-            raise MyException("Too much disk requested")
+            raise InvalidInput("Too much disk requested")
         if not canAddVm(user):
-            raise MyException("Too many VMs requested")
+            raise InvalidInput("Too many VMs requested")
         res = meta.engine.execute('select nextval(\'"machines_machine_id_seq"\')')
         id = res.fetchone()[0]
@@ -246 +276 @@
         open = NIC.select_by(machine_id=None)
         if not open: #No IPs left!
-            return "No IP addresses left!  Contact sipb-xen-dev@mit.edu"
+            raise CodeError("No IP addresses left!  Contact sipb-xen-dev@mit.edu")
         nic = open[0]
         nic.machine_id = machine.machine_id
@@ -264 +294 @@
 
 def validMemory(user, memory, machine=None):
+    """Parse and validate limits for memory for a given user and machine."""
     try:
         memory = int(memory)
@@ -269 +300 @@
             raise ValueError
     except ValueError:
-        raise MyException("Invalid memory amount; must be at least %s MB" %
+        raise InvalidInput("Invalid memory amount; must be at least %s MB" %
                           MIN_MEMORY_SINGLE)
     if memory > maxMemory(user, machine):
-        raise MyException("Too much memory requested")
+        raise InvalidInput("Too much memory requested")
     return memory
 
 def validDisk(user, disk, machine=None):
+    """Parse and validate limits for disk for a given user and machine."""
     try:
         disk = float(disk)
         if disk > maxDisk(user, machine):
-            raise MyException("Too much disk requested")
+            raise InvalidInput("Too much disk requested")
         disk = int(disk * 1024)
         if disk < MIN_DISK_SINGLE * 1024:
             raise ValueError
     except ValueError:
-        raise MyException("Invalid disk amount; minimum is %s GB" %
+        raise InvalidInput("Invalid disk amount; minimum is %s GB" %
                           MIN_DISK_SINGLE)
     return disk
 
 def create(user, fields):
+    """Handler for create requests."""
     name = fields.getfirst('name')
     if not validMachineName(name):
-        raise MyException("Invalid name '%s'" % name)
+        raise InvalidInput("Invalid name '%s'" % name)
     name = user.username + '_' + name.lower()
 
     if Machine.get_by(name=name):
-        raise MyException("A machine named '%s' already exists" % name)
+        raise InvalidInput("A machine named '%s' already exists" % name)
     
     memory = fields.getfirst('memory')
@@ -305 +338 @@
     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)    
+        raise CodeError("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)
@@ -321 +352 @@
 
 def listVms(user, fields):
+    """Handler for list requests."""
     machines = [m for m in Machine.select() if haveAccess(user, m)]    
     on = {}
@@ -352 +384 @@
 
 def testMachineId(user, machineId, exists=True):
+    """Parse, validate and check authorization for a given machineId.
+
+    If exists is False, don't check that it exists.
+    """
     if machineId is None:
-        raise MyException("No machine ID specified")
+        raise CodeError("No machine ID specified")
     try:
         machineId = int(machineId)
     except ValueError:
-        raise MyException("Invalid machine ID '%s'" % machineId)
+        raise CodeError("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)
+        raise CodeError("No such machine ID '%s'" % machineId)
+    if machine is not None and not haveAccess(user, machine):
+        raise CodeError("No access to machine ID '%s'" % machineId)
     return machine
 
@@ -378 +414 @@
     -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
     
     TOKEN_KEY = "0M6W0U1IXexThi5idy8mnkqPKEq1LtEnlK/pZSn0cDrN"
@@ -403 +441 @@
 
 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'),
@@ -419 +462 @@
 
 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')]
@@ -429 +477 @@
 
 def deleteVM(machine):
+    """Delete a VM."""
     transaction = ctx.current.create_transaction()
     delete_disk_pairs = [(machine.name, d.guest_device_name) for d in machine.disks]
@@ -448 +497 @@
 
 def command(user, fields):
+    """Handler for running commands like boot and delete on a VM."""
     print time.time()-start_time
     machine = testMachineId(user, fields.getfirst('machine_id'))
@@ -454 +504 @@
     print time.time()-start_time
     if cdrom is not None and not CDROM.get(cdrom):
-        raise MyException("Invalid cdrom type '%s'" % cdrom)    
+        raise CodeError("Invalid cdrom type '%s'" % cdrom)    
     if action not in ('Reboot', 'Power on', 'Power off', 'Shutdown', 'Delete VM'):
-        raise MyException("Invalid action '%s'" % action)
+        raise CodeError("Invalid action '%s'" % action)
     if action == 'Reboot':
         if cdrom is not None:
@@ -464 +514 @@
     elif action == 'Power on':
         if maxMemory(user) < machine.memory:
-            raise MyException("You don't have enough free RAM quota")
+            raise InvalidInput("You don't have enough free RAM quota")
         bootMachine(machine, cdrom)
     elif action == 'Power off':
@@ -480 +530 @@
         
 def modify(user, fields):
+    """Handler for modifying attributes of a machine."""
+    #XXX not written yet
     machine = testMachineId(user, fields.getfirst('machine_id'))
     
 def help(user, fields):
+    """Handler for help messages."""
     simple = fields.getfirst('simple')
     subjects = fields.getlist('subject')
@@ -505 +558 @@
 
 def info(user, fields):
+    """Handler for info on a single VM."""
     machine = testMachineId(user, fields.getfirst('machine_id'))
     status = statusInfo(machine)
@@ -622 +676 @@
     try:
         fun(u, fields)
-    except MyException, err:
+    except CodeError, err:
         error(operation, u, fields, err)
+    except InvalidInput, err:
+        error(operation, u, fields, err)