Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

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import datetime

from django.conf import settings

from django.db import models

from django.db import IntegrityError

from hashlib import sha1

from synnefo.api.faults import ServiceUnavailable

from synnefo.util.rapi import GanetiRapiClient

BACKEND_CLIENTS = {}    #{hash:Backend client}

BACKEND_HASHES = {}     #{Backend.id:hash}

def get_client(hash, backend):

    """Get a cached backend client or create a new one.

    @param hash: The hash of the backend

    @param backend: Either a backend object or backend ID

    """

    if backend is None:

        raise Exception("Backend is None. Cannot create a client.")

    if hash in BACKEND_CLIENTS:

        # Return cached client

        return BACKEND_CLIENTS[hash]

    # Always get a new instance to ensure latest credentials

    if isinstance(backend, Backend):

        backend = backend.id

    (credentials,) = Backend.objects.filter(id=backend).values_list('hash',

                                'clustername', 'port', 'username', 'password')

    hash, clustername, port, user, password = credentials

    # Check client for updated hash

    if hash in BACKEND_CLIENTS:

        return BACKEND_CLIENTS[hash]

    # Delete old version of the client

    if backend in BACKEND_HASHES:

        del BACKEND_CLIENTS[BACKEND_HASHES[backend]]

    # Create the new client

    client = GanetiRapiClient(clustername, port, user, password)

    # Store the client and the hash

    BACKEND_CLIENTS[hash] = client

    BACKEND_HASHES[backend] = hash

    return client

def clear_client_cache():

    BACKEND_CLIENTS.clear()

    BACKEND_HASHES.clear()

class Flavor(models.Model):

    cpu = models.IntegerField('Number of CPUs', default=0)

    ram = models.IntegerField('RAM size in MiB', default=0)

    disk = models.IntegerField('Disk size in GiB', default=0)

    disk_template = models.CharField('Disk template', max_length=32,

            default=settings.DEFAULT_GANETI_DISK_TEMPLATE)

    deleted = models.BooleanField('Deleted', default=False)

    class Meta:

        verbose_name = u'Virtual machine flavor'

        unique_together = ('cpu', 'ram', 'disk', 'disk_template')

    @property

    def name(self):

        """Returns flavor name (generated)"""

        return u'C%dR%dD%d' % (self.cpu, self.ram, self.disk)

    def __unicode__(self):

        return self.name

class BackendQuerySet(models.query.QuerySet):

    def delete(self):

        for backend in self._clone():

            backend.delete()

class ProtectDeleteManager(models.Manager):

    def get_query_set(self):

        return BackendQuerySet(self.model, using=self._db)

class Backend(models.Model):

    clustername = models.CharField('Cluster Name', max_length=128, unique=True)

    port = models.PositiveIntegerField('Port', default=5080)

    username = models.CharField('Username', max_length=64, blank=True,

                                null=True)

    password = models.CharField('Password', max_length=64, blank=True,

                                null=True)

    # Sha1 is up to 40 characters long

    hash = models.CharField('Hash', max_length=40, editable=False, null=False)

    drained = models.BooleanField('Drained', default=False, null=False)

    offline = models.BooleanField('Offline', default=False, null=False)

    # Last refresh of backend resources

    updated = models.DateTimeField(auto_now_add=True)

    # Backend resources

    mfree = models.PositiveIntegerField('Free Memory', default=0, null=False)

    mtotal = models.PositiveIntegerField('Total Memory', default=0, null=False)

    dfree = models.PositiveIntegerField('Free Disk', default=0, null=False)

    dtotal = models.PositiveIntegerField('Total Disk', default=0, null=False)

    pinst_cnt = models.PositiveIntegerField('Primary Instances', default=0,

                                            null=False)

    ctotal = models.PositiveIntegerField('Total number of logical processors',

                                         default=0, null=False)

    # Custom object manager to protect from cascade delete

    objects = ProtectDeleteManager()

    class Meta:

        verbose_name = u'Backend'

        ordering = ["clustername"]

    def __unicode__(self):

        return self.clustername

    @property

    def backend_id(self):

        return self.id

    @property

    def client(self):

        """Get or create a client. """

        if not self.offline:

            return get_client(self.hash, self)

        else:

            raise ServiceUnavailable

    def create_hash(self):

        """Create a hash for this backend. """

        return sha1('%s%s%s%s' % \

                (self.clustername, self.port, self.username, self.password)) \

                .hexdigest()

    def save(self, *args, **kwargs):

        # Create a new hash each time a Backend is saved

        old_hash = self.hash

        self.hash = self.create_hash()

        super(Backend, self).save(*args, **kwargs)

        if self.hash != old_hash:

            # Populate the new hash to the new instances

            self.virtual_machines.filter(deleted=False).update(backend_hash=self.hash)

    def delete(self, *args, **kwargs):

        # Integrity Error if non-deleted VMs are associated with Backend

        if self.virtual_machines.filter(deleted=False).count():

            raise IntegrityError("Non-deleted virtual machines are associated "

                                 "with backend: %s" % self)

        else:

            # ON_DELETE = SET NULL

            self.virtual_machines.all().backend=None

            super(Backend, self).delete(*args, **kwargs)

class VirtualMachine(models.Model):

    # The list of possible actions for a VM

    ACTIONS = (

       ('CREATE', 'Create VM'),

       ('START', 'Start VM'),

       ('STOP', 'Shutdown VM'),

       ('SUSPEND', 'Admin Suspend VM'),

       ('REBOOT', 'Reboot VM'),

       ('DESTROY', 'Destroy VM')

    )

    # The internal operating state of a VM

    OPER_STATES = (

        ('BUILD', 'Queued for creation'),

        ('ERROR', 'Creation failed'),

        ('STOPPED', 'Stopped'),

        ('STARTED', 'Started'),

        ('DESTROYED', 'Destroyed')

    )

    # The list of possible operations on the backend

    BACKEND_OPCODES = (

        ('OP_INSTANCE_CREATE', 'Create Instance'),

        ('OP_INSTANCE_REMOVE', 'Remove Instance'),

        ('OP_INSTANCE_STARTUP', 'Startup Instance'),

        ('OP_INSTANCE_SHUTDOWN', 'Shutdown Instance'),

        ('OP_INSTANCE_REBOOT', 'Reboot Instance'),

        # These are listed here for completeness,

        # and are ignored for the time being

        ('OP_INSTANCE_SET_PARAMS', 'Set Instance Parameters'),

        ('OP_INSTANCE_QUERY_DATA', 'Query Instance Data'),

        ('OP_INSTANCE_REINSTALL', 'Reinstall Instance'),

        ('OP_INSTANCE_ACTIVATE_DISKS', 'Activate Disks'),

        ('OP_INSTANCE_DEACTIVATE_DISKS', 'Deactivate Disks'),

        ('OP_INSTANCE_REPLACE_DISKS', 'Replace Disks'),

        ('OP_INSTANCE_MIGRATE', 'Migrate Instance'),

        ('OP_INSTANCE_CONSOLE', 'Get Instance Console'),

        ('OP_INSTANCE_RECREATE_DISKS', 'Recreate Disks'),

        ('OP_INSTANCE_FAILOVER', 'Failover Instance')

    )

    # A backend job may be in one of the following possible states

    BACKEND_STATUSES = (

        ('queued', 'request queued'),

        ('waiting', 'request waiting for locks'),

        ('canceling', 'request being canceled'),

        ('running', 'request running'),

        ('canceled', 'request canceled'),

        ('success', 'request completed successfully'),

        ('error', 'request returned error')

    )

    # The operating state of a VM,

    # upon the successful completion of a backend operation.

    # IMPORTANT: Make sure all keys have a corresponding

    # entry in BACKEND_OPCODES if you update this field, see #1035, #1111.

    OPER_STATE_FROM_OPCODE = {

        'OP_INSTANCE_CREATE': 'STARTED',

        'OP_INSTANCE_REMOVE': 'DESTROYED',

        'OP_INSTANCE_STARTUP': 'STARTED',

        'OP_INSTANCE_SHUTDOWN': 'STOPPED',

        'OP_INSTANCE_REBOOT': 'STARTED',

        'OP_INSTANCE_SET_PARAMS': None,

        'OP_INSTANCE_QUERY_DATA': None,

        'OP_INSTANCE_REINSTALL': None,

        'OP_INSTANCE_ACTIVATE_DISKS': None,

        'OP_INSTANCE_DEACTIVATE_DISKS': None,

        'OP_INSTANCE_REPLACE_DISKS': None,

        'OP_INSTANCE_MIGRATE': None,

        'OP_INSTANCE_CONSOLE': None,

        'OP_INSTANCE_RECREATE_DISKS': None,

        'OP_INSTANCE_FAILOVER': None

    }

    # This dictionary contains the correspondence between

    # internal operating states and Server States as defined

    # by the Rackspace API.

    RSAPI_STATE_FROM_OPER_STATE = {

        "BUILD": "BUILD",

        "ERROR": "ERROR",

        "STOPPED": "STOPPED",

        "STARTED": "ACTIVE",

        "DESTROYED": "DELETED"

    }

    name = models.CharField('Virtual Machine Name', max_length=255)

    userid = models.CharField('User ID of the owner', max_length=100)

    backend = models.ForeignKey(Backend, null=True,

                                related_name="virtual_machines",)

    backend_hash = models.CharField(max_length=128, null=True, editable=False)

    created = models.DateTimeField(auto_now_add=True)

    updated = models.DateTimeField(auto_now=True)

    imageid = models.CharField(max_length=100, null=False)

    hostid = models.CharField(max_length=100)

    flavor = models.ForeignKey(Flavor)

    deleted = models.BooleanField('Deleted', default=False)

    suspended = models.BooleanField('Administratively Suspended',

                                    default=False)

    # VM State

    # The following fields are volatile data, in the sense

    # that they need not be persistent in the DB, but rather

    # get generated at runtime by quering Ganeti and applying

    # updates received from Ganeti.

    # In the future they could be moved to a separate caching layer

    # and removed from the database.

    # [vkoukis] after discussion with [faidon].

    action = models.CharField(choices=ACTIONS, max_length=30, null=True)

    operstate = models.CharField(choices=OPER_STATES, max_length=30, null=True)

    backendjobid = models.PositiveIntegerField(null=True)

    backendopcode = models.CharField(choices=BACKEND_OPCODES, max_length=30,

                                     null=True)

    backendjobstatus = models.CharField(choices=BACKEND_STATUSES,

                                        max_length=30, null=True)

    backendlogmsg = models.TextField(null=True)

    buildpercentage = models.IntegerField(default=0)

    backendtime = models.DateTimeField(default=datetime.datetime.min)

    @property

    def client(self):

        if not self.backend.offline:

            return get_client(self.backend_hash, self.backend_id)

        else:

            raise ServiceUnavailable

    # Error classes

    class InvalidBackendIdError(Exception):

        def __init__(self, value):

            self.value = value

        def __str__(self):

            return repr(self.value)

    class InvalidBackendMsgError(Exception):

        def __init__(self, opcode, status):

            self.opcode = opcode

            self.status = status

        def __str__(self):

            return repr('<opcode: %s, status: %s>' % (self.opcode,

                        self.status))

    class InvalidActionError(Exception):

        def __init__(self, action):

            self._action = action

        def __str__(self):

            return repr(str(self._action))

    class DeletedError(Exception):

        pass

    class BuildingError(Exception):

        pass

    def __init__(self, *args, **kw):

        """Initialize state for just created VM instances."""

        super(VirtualMachine, self).__init__(*args, **kw)

        # This gets called BEFORE an instance gets save()d for

        # the first time.

        if not self.pk:

            self.action = None

            self.backendjobid = None

            self.backendjobstatus = None

            self.backendopcode = None

            self.backendlogmsg = None

            self.operstate = 'BUILD'

    def save(self, *args, **kwargs):

        # Store hash for first time saved vm

        if (self.id is None or self.backend_hash == '') and self.backend:

            self.backend_hash = self.backend.hash

        super(VirtualMachine, self).save(*args, **kwargs)

    @property

    def backend_vm_id(self):

        """Returns the backend id for this VM by prepending backend-prefix."""

        if not self.id:

            raise VirtualMachine.InvalidBackendIdError("self.id is None")

        return '%s%s' % (settings.BACKEND_PREFIX_ID, self.id)

    class Meta:

        verbose_name = u'Virtual machine instance'

        get_latest_by = 'created'

    def __unicode__(self):

        return self.name

class VirtualMachineMetadata(models.Model):

    meta_key = models.CharField(max_length=50)

    meta_value = models.CharField(max_length=500)

    vm = models.ForeignKey(VirtualMachine, related_name='metadata')

    class Meta:

        unique_together = (('meta_key', 'vm'),)

        verbose_name = u'Key-value pair of metadata for a VM.'

    def __unicode__(self):

        return u'%s: %s' % (self.meta_key, self.meta_value)

class Network(models.Model):

    NETWORK_STATES = (

        ('ACTIVE', 'Active'),

        ('DELETED', 'Deleted')

    )

    name = models.CharField(max_length=255)

    created = models.DateTimeField(auto_now_add=True)

    updated = models.DateTimeField(auto_now=True)

    userid = models.CharField('User ID of the owner', max_length=100,

                              null=True)

    state = models.CharField(choices=NETWORK_STATES, max_length=30)

    public = models.BooleanField(default=False)

    link = models.ForeignKey('NetworkLink', related_name='+')

    machines = models.ManyToManyField(VirtualMachine,

                                      through='NetworkInterface')

    def __unicode__(self):

        return self.name

class NetworkInterface(models.Model):

    FIREWALL_PROFILES = (

        ('ENABLED', 'Enabled'),

        ('DISABLED', 'Disabled'),

        ('PROTECTED', 'Protected')

    )

    machine = models.ForeignKey(VirtualMachine, related_name='nics')

    network = models.ForeignKey(Network, related_name='nics')

    created = models.DateTimeField(auto_now_add=True)

    updated = models.DateTimeField(auto_now=True)

    index = models.IntegerField(null=True)

    mac = models.CharField(max_length=17, null=True)

    ipv4 = models.CharField(max_length=15, null=True)

    ipv6 = models.CharField(max_length=100, null=True)

    firewall_profile = models.CharField(choices=FIREWALL_PROFILES,

                                        max_length=30, null=True)

    def __unicode__(self):

        return '%s@%s' % (self.machine.name, self.network.name)

class NetworkLink(models.Model):

    network = models.ForeignKey(Network, null=True, related_name='+')

    index = models.IntegerField()

    name = models.CharField(max_length=255)

    available = models.BooleanField(default=True)

    def __unicode__(self):

        return self.name

    class NotAvailable(Exception):

        pass