Source code for elasticluster.providers.ec2_boto

#
# Copyright (C) 2013, 2018, 2019  University of Zurich.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

__author__ = ', '.join([
    'Nicolas Baer <nicolas.baer@uzh.ch>',
    'Antonio Messina <antonio.s.messina@gmail.com>',
    'Riccardo Murri <riccardo.murri@gmail.com>',
])

# compatibility imports
from future import standard_library
standard_library.install_aliases()

# stdlib imports
from builtins import range
import hashlib
import os
import sys
import urllib.request, urllib.parse, urllib.error
import threading
import time
from warnings import warn

# External modules
import boto
import boto.ec2
import boto.vpc
from Crypto.PublicKey import RSA
from paramiko import DSSKey, RSAKey, PasswordRequiredException
from paramiko.ssh_exception import SSHException

# Elasticluster imports
from elasticluster import log
from elasticluster.providers import AbstractCloudProvider
from elasticluster.exceptions import (
    CloudProviderError,
    ClusterError,
    ImageError,
    InstanceError,
    InstanceNotFoundError,
    KeypairError,
    SecurityGroupError,
    SubnetError,
    VpcError,
)
from elasticluster.utils import fingerprint_str


[docs]class BotoCloudProvider(AbstractCloudProvider): """This implementation of :py:class:`elasticluster.providers.AbstractCloudProvider` uses the boto ec2 interface to connect to ec2 compliant clouds and manage instances. Please check https://github.com/boto/boto for further information about the supported cloud platforms. :param str ec2_url: url to connect to cloud web service :param str ec2_region: region identifier :param str ec2_access_key: access key of the user account :param str ec2_secret_key: secret key of the user account :param str storage_path: path to store temporary data :param bool request_floating_ip: Whether ip are assigned automatically `True` or floating ips have to be assigned manually `False` :param str instance_profile: Instance profile with IAM role permissions :param float price: Spot instance price (if 0, do not use spot instances); used as a default in `start_instance`:py:meth :param int price: Timeout waiting for spot instances (only used if price > 0); used as a default in `start_instance`:py:meth """ __node_start_lock = threading.Lock() # lock used for node startup # interval (in seconds) for polling the cloud provider, # e.g., when requesting spot instances POLL_INTERVAL = 10 def __init__(self, ec2_url, ec2_region, ec2_access_key=None, ec2_secret_key=None, vpc=None, storage_path=None, request_floating_ip=False, instance_profile=None, price=0.0, timeout=0): self._url = ec2_url self._access_key = ec2_access_key self._secret_key = ec2_secret_key self._vpc = vpc self._instance_profile = instance_profile self.request_floating_ip = request_floating_ip # provide defaults for like-named arguments in `.start_instance` self.price = price self.timeout = timeout # read all parameters from url proto, opaqueurl = urllib.parse.splittype(ec2_url) self._host, self._ec2path = urllib.parse.splithost(opaqueurl) self._ec2host, port = urllib.parse.splitport(self._host) if port: port = int(port) self._ec2port = port if proto == "https": self._secure = True else: self._secure = False self._region_name = ec2_region # will be initialized upon first connect self._ec2_connection = None self._vpc_connection = None self._vpc_id = None self._instances = {} self._cached_instances = [] self._images = None
[docs] def to_vars_dict(self): """ Return local state which is relevant for the cluster setup process. """ return { 'aws_access_key_id': self._access_key, 'aws_secret_access_key': self._secret_key, 'aws_region': self._region_name, 'aws_vpc_name': (self._vpc or ''), 'aws_vpc_id': (self._vpc_id or ''), }
def _connect(self): """ Connect to the EC2 cloud provider. :return: :py:class:`boto.ec2.connection.EC2Connection` :raises: Generic exception on error """ # check for existing connection if self._ec2_connection: return self._ec2_connection try: log.debug("Connecting to EC2 endpoint %s", self._ec2host) # connect to webservice ec2_connection = boto.ec2.connect_to_region( self._region_name, aws_access_key_id=self._access_key, aws_secret_access_key=self._secret_key, is_secure=self._secure, host=self._ec2host, port=self._ec2port, path=self._ec2path, ) # With the loose setting `BOTO_USE_ENDPOINT_HEURISTICS` # which is necessary to work around issue #592, Boto will # now accept *any* string as an AWS region name; # furthermore, it *always* returns a connection object -- # so the only way to check that we are not going to run # into trouble is to check that there *is* a valid host # name on the other end of the connection. if ec2_connection.host: log.debug("EC2 connection has been successful.") else: raise CloudProviderError( "Cannot establish connection to EC2 region {0}" .format(self._region_name)) if not self._vpc: vpc_connection = None self._vpc_id = None else: vpc_connection, self._vpc_id = self._find_vpc_by_name(self._vpc) except Exception as err: log.error("Error connecting to EC2: %s", err) raise self._ec2_connection, self._vpc_connection = ( ec2_connection, vpc_connection) return self._ec2_connection def _find_vpc_by_name(self, vpc_name): vpc_connection = boto.vpc.connect_to_region( self._region_name, aws_access_key_id=self._access_key, aws_secret_access_key=self._secret_key, is_secure=self._secure, host=self._ec2host, port=self._ec2port, path=self._ec2path, ) log.debug("VPC connection has been successful.") for vpc in vpc_connection.get_all_vpcs(): matches = [vpc.id] if 'Name' in vpc.tags: matches.append(vpc.tags['Name']) if vpc_name in matches: vpc_id = vpc.id if vpc_name != vpc_id: # then `vpc_name` is the VPC name log.debug("VPC `%s` has ID `%s`", vpc_name, vpc_id) break else: raise VpcError('Cannot find VPC `{0}`.'.format(vpc_name)) return (vpc_connection, vpc_id)
[docs] def start_instance(self, key_name, public_key_path, private_key_path, security_group, flavor, image_id, image_userdata, cluster_name, username=None, node_name=None, network_ids=None, price=None, timeout=None, boot_disk_device=None, boot_disk_size=None, boot_disk_type=None, boot_disk_iops=None, placement_group=None, **kwargs): """Starts a new instance on the cloud using the given properties. The following tasks are done to start an instance: * establish a connection to the cloud web service * check ssh keypair and upload it if it does not yet exist. This is a locked process, since this function might be called in multiple threads and we only want the key to be stored once. * check if the security group exists * run the instance with the given properties :param str key_name: name of the ssh key to connect :param str public_key_path: path to ssh public key :param str private_key_path: path to ssh private key :param str security_group: firewall rule definition to apply on the instance :param str flavor: machine type to use for the instance :param str image_id: image type (os) to use for the instance :param str image_userdata: command to execute after startup :param str username: username for the given ssh key, default None :param float price: Spot instance price (if 0, do not use spot instances). :param int price: Timeout (in seconds) waiting for spot instances; only used if price > 0. :param str boot_disk_device: Root volume device path if not /dev/sda1 :param str boot_disk_size: Target size, in GiB, for the root volume :param str boot_disk_type: Type of root volume (standard, gp2, io1) :param str boot_disk_iops: Provisioned IOPS for the root volume :param str placement_group: Enable low-latency networking between compute nodes. :return: str - instance id of the started instance """ connection = self._connect() log.debug("Checking keypair `%s`.", key_name) # the `_check_keypair` method has to be called within a lock, # since it will upload the key if it does not exist and if this # happens for every node at the same time ec2 will throw an error # message (see issue #79) with BotoCloudProvider.__node_start_lock: self._check_keypair(key_name, public_key_path, private_key_path) log.debug("Checking security group `%s`.", security_group) security_group_id = self._check_security_group(security_group) # image_id = self._find_image_id(image_id) if network_ids: interfaces = [] for subnet in network_ids.split(','): subnet_id = self._check_subnet(subnet) interfaces.append( boto.ec2.networkinterface.NetworkInterfaceSpecification( subnet_id=subnet_id, groups=[security_group_id], associate_public_ip_address=self.request_floating_ip)) interfaces = boto.ec2.networkinterface.NetworkInterfaceCollection(*interfaces) security_groups = [] else: interfaces = None security_groups = [security_group] # get defaults for `price` and `timeout` from class instance if price is None: price = self.price if timeout is None: timeout = self.timeout if boot_disk_size: dev_root = boto.ec2.blockdevicemapping.BlockDeviceType() dev_root.size = int(boot_disk_size) dev_root.delete_on_termination = True if boot_disk_type: dev_root.volume_type = boot_disk_type if boot_disk_iops: dev_root.iops = int(boot_disk_iops) bdm = boto.ec2.blockdevicemapping.BlockDeviceMapping() dev_name = boot_disk_device if boot_disk_device else "/dev/sda1" bdm[dev_name] = dev_root else: bdm = None try: #start spot instance if bid is specified if price: log.info("Requesting spot instance with price `%s` ...", price) request = connection.request_spot_instances( price,image_id, key_name=key_name, security_groups=security_groups, instance_type=flavor, user_data=image_userdata, network_interfaces=interfaces, placement_group=placement_group, block_device_map=bdm, instance_profile_name=self._instance_profile)[-1] # wait until spot request is fullfilled (will wait # forever if no timeout is given) start_time = time.time() timeout = (float(timeout) if timeout else 0) log.info("Waiting for spot instance (will time out in %d seconds) ...", timeout) while request.status.code != 'fulfilled': if timeout and time.time()-start_time > timeout: request.cancel() raise RuntimeError('spot instance timed out') time.sleep(self.POLL_INTERVAL) # update request status request=connection.get_all_spot_instance_requests(request_ids=request.id)[-1] else: reservation = connection.run_instances( image_id, key_name=key_name, security_groups=security_groups, instance_type=flavor, user_data=image_userdata, network_interfaces=interfaces, placement_group=placement_group, block_device_map=bdm, instance_profile_name=self._instance_profile) except Exception as ex: log.error("Error starting instance: %s", ex) if "TooManyInstances" in ex: raise ClusterError(ex) else: raise InstanceError(ex) if price: vm = connection.get_only_instances(instance_ids=[request.instance_id])[-1] else: vm = reservation.instances[-1] vm.add_tag("Name", node_name) # cache instance object locally for faster access later on self._instances[vm.id] = vm return { 'instance_id': vm.id }
[docs] def stop_instance(self, node): """ Destroy a VM. :param Node node: A `Node`:class: instance """ instance_id = node.instance_id instance = self._load_instance(instance_id) instance.terminate() del self._instances[instance_id]
[docs] def resume_instance(self, instance_state): raise NotImplementedError("This provider does not (yet) support pause / resume logic.")
[docs] def pause_instance(self, instance_id): raise NotImplementedError("This provider does not (yet) support pause / resume logic.")
[docs] def get_ips(self, instance_id): """Retrieves the private and public ip addresses for a given instance. :return: list (ips) """ self._load_instance(instance_id) instance = self._load_instance(instance_id) IPs = [ip for ip in (instance.private_ip_address, instance.ip_address) if ip] # We also need to check if there is any floating IP associated if self.request_floating_ip and not self._vpc: # We need to list the floating IPs for this instance floating_ips = [ip for ip in self._ec2_connection.get_all_addresses() if ip.instance_id == instance.id] if not floating_ips: log.debug("Public ip address has to be assigned through " "elasticluster.") ip = self._allocate_address(instance) # This is probably the preferred IP we want to use IPs.insert(0, ip) else: IPs = [ip.public_ip for ip in floating_ips] + IPs return list(set(IPs))
[docs] def is_instance_running(self, instance_id): """Checks if the instance is up and running. :param str instance_id: instance identifier :return: bool - True if running, False otherwise """ instance = self._load_instance(instance_id) if instance.update() == "running": # If the instance is up&running, ensure it has an IP # address. if not instance.ip_address and self.request_floating_ip: log.debug("Public ip address has to be assigned through " "elasticluster.") self._allocate_address(instance) instance.update() return True else: return False
def _allocate_address(self, instance): """Allocates a free public ip address to the given instance :param instance: instance to assign address to :type instance: py:class:`boto.ec2.instance.Reservation` :return: public ip address """ connection = self._connect() free_addresses = [ ip for ip in connection.get_all_addresses() if not ip.instance_id] if not free_addresses: try: address = connection.allocate_address() except Exception as ex: log.error("Unable to allocate a public IP address to instance `%s`", instance.id) return None try: address = free_addresses.pop() instance.use_ip(address) return address.public_ip except Exception as ex: log.error("Unable to associate IP address %s to instance `%s`", address, instance.id) return None def _load_instance(self, instance_id): """ Return instance with the given id. For performance reasons, the instance ID is first searched for in the collection of VM instances started by ElastiCluster (`self._instances`), then in the list of all instances known to the cloud provider at the time of the last update (`self._cached_instances`), and finally the cloud provider is directly queried. :param str instance_id: instance identifier :return: py:class:`boto.ec2.instance.Reservation` - instance :raises: `InstanceError` is returned if the instance can't be found in the local cache or in the cloud. """ # if instance is known, return it if instance_id in self._instances: return self._instances[instance_id] # else, check (cached) list from provider if instance_id not in self._cached_instances: self._cached_instances = self._build_cached_instances() if instance_id in self._cached_instances: inst = self._cached_instances[instance_id] self._instances[instance_id] = inst return inst # If we reached this point, the instance was not found neither # in the caches nor on the website. raise InstanceNotFoundError( "Instance `{instance_id}` not found" .format(instance_id=instance_id)) def _build_cached_instances(self): """ Build lookup table of VM instances known to the cloud provider. The returned dictionary links VM id with the actual VM object. """ connection = self._connect() reservations = connection.get_all_reservations() cached_instances = {} for rs in reservations: for vm in rs.instances: cached_instances[vm.id] = vm return cached_instances def _check_keypair(self, name, public_key_path, private_key_path): """First checks if the keypair is valid, then checks if the keypair is registered with on the cloud. If not the keypair is added to the users ssh keys. :param str name: name of the ssh key :param str public_key_path: path to the ssh public key file :param str private_key_path: path to the ssh private key file :raises: `KeypairError` if key is not a valid RSA or DSA key, the key could not be uploaded or the fingerprint does not match to the one uploaded to the cloud. """ connection = self._connect() keypairs = connection.get_all_key_pairs() keypairs = dict((k.name, k) for k in keypairs) # decide if dsa or rsa key is provided pkey = None is_dsa_key = False try: pkey = DSSKey.from_private_key_file(private_key_path) is_dsa_key = True except PasswordRequiredException: warn("Unable to check key file `{0}` because it is encrypted with a " "password. Please, ensure that you added it to the SSH agent " "with `ssh-add {1}`" .format(private_key_path, private_key_path)) except SSHException: try: pkey = RSAKey.from_private_key_file(private_key_path) except PasswordRequiredException: warn("Unable to check key file `{0}` because it is encrypted with a " "password. Please, ensure that you added it to the SSH agent " "with `ssh-add {1}`" .format(private_key_path, private_key_path)) except SSHException: raise KeypairError('File `%s` is neither a valid DSA key ' 'or RSA key.' % private_key_path) # create keys that don't exist yet if name not in keypairs: log.warning( "Keypair `%s` not found on resource `%s`, Creating a new one", name, self._url) with open(os.path.expanduser(public_key_path)) as f: key_material = f.read() try: # check for DSA on amazon if "amazon" in self._ec2host and is_dsa_key: log.error( "Apparently, amazon does not support DSA keys. " "Please specify a valid RSA key.") raise KeypairError( "Apparently, amazon does not support DSA keys." "Please specify a valid RSA key.") connection.import_key_pair(name, key_material) except Exception as ex: log.error( "Could not import key `%s` with name `%s` to `%s`", name, public_key_path, self._url) raise KeypairError( "could not create keypair `%s`: %s" % (name, ex)) else: # check fingerprint cloud_keypair = keypairs[name] if pkey: if "amazon" in self._ec2host: # AWS takes the MD5 hash of the key's DER representation. key = RSA.importKey(open(private_key_path).read()) der = key.publickey().exportKey('DER') m = hashlib.md5() m.update(der) digest = m.hexdigest() fingerprint = ':'.join(digest[i:(i + 2)] for i in range(0, len(digest), 2)) else: fingerprint = fingerprint_str(pkey) if fingerprint != cloud_keypair.fingerprint: if "amazon" in self._ec2host: log.error( "Apparently, Amazon does not compute the RSA key " "fingerprint as we do! We cannot check if the " "uploaded keypair is correct!") else: raise KeypairError( "Keypair `%s` is present but has " "different fingerprint. Aborting!" % name) def _check_security_group(self, name): """Checks if the security group exists. :param str name: name of the security group :return: str - security group id of the security group :raises: `SecurityGroupError` if group does not exist """ connection = self._connect() filters = {} if self._vpc: filters = {'vpc-id': self._vpc_id} security_groups = connection.get_all_security_groups(filters=filters) matching_groups = [ group for group in security_groups if name in [group.name, group.id] ] if len(matching_groups) == 0: raise SecurityGroupError( "the specified security group %s does not exist" % name) elif len(matching_groups) == 1: return matching_groups[0].id elif self._vpc and len(matching_groups) > 1: raise SecurityGroupError( "the specified security group name %s matches " "more than one security group" % name) def _check_subnet(self, name): """Checks if the subnet exists. :param str name: name of the subnet :return: str - subnet id of the subnet :raises: `SubnetError` if group does not exist """ # Subnets only exist in VPCs, so we don't need to worry about # the EC2 Classic case here. subnets = self._vpc_connection.get_all_subnets( filters={'vpcId': self._vpc_id}) matching_subnets = [ subnet for subnet in subnets if name in [subnet.tags.get('Name'), subnet.id] ] if len(matching_subnets) == 0: raise SubnetError( "the specified subnet %s does not exist" % name) elif len(matching_subnets) == 1: return matching_subnets[0].id else: raise SubnetError( "the specified subnet name %s matches more than " "one subnet" % name) def _find_image_id(self, image_id): """Finds an image id to a given id or name. :param str image_id: name or id of image :return: str - identifier of image """ if not self._images: connection = self._connect() self._images = connection.get_all_images() image_id_cloud = None for i in self._images: if i.id == image_id or i.name == image_id: image_id_cloud = i.id break if image_id_cloud: return image_id_cloud else: raise ImageError( "Could not find given image id `%s`" % image_id) def __getstate__(self): d = self.__dict__.copy() del d['_ec2_connection'] del d['_vpc_connection'] return d def __setstate__(self, state): self.__dict__ = state self._ec2_connection = None self._vpc_connection = None