126 lines
4.9 KiB
ReStructuredText
126 lines
4.9 KiB
ReStructuredText
.. _guide_migration_ec2:
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Amazon EC2
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==========
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Boto 2.x contains a number of customizations to make working with Amazon EC2 instances, storage and networks easy. Boto 3 exposes these same objects through its resources interface in a unified and consistent way.
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Creating the Connection
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-----------------------
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Boto 3 has both low-level clients and higher-level resources. For Amazon EC2, the higher-level resources are the most similar to Boto 2.x's ``ec2`` and ``vpc`` modules::
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# Boto 2.x
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import boto
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ec2_connection = boto.connect_ec2()
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vpc_connection = boto.connect_vpc()
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# Boto 3
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import boto3
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ec2 = boto3.resource('ec2')
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Launching New Instances
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-----------------------
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Launching new instances requires an image ID and the number of instances to launch. It can also take several optional parameters, such as the instance type and security group::
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# Boto 2.x
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ec2_connection.run_instances('<ami-image-id>')
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# Boto 3
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ec2.create_instances(ImageId='<ami-image-id>', MinCount=1, MaxCount=5)
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Stopping & Terminating Instances
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--------------------------------
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Stopping and terminating multiple instances given a list of instance IDs uses Boto 3 collection filtering::
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ids = ['instance-id-1', 'instance-id-2', ...]
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# Boto 2.x
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ec2_connection.stop_instances(instance_ids=ids)
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ec2_connection.terminate_instances(instance_ids=ids)
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# Boto 3
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ec2.instances.filter(InstanceIds=ids).stop()
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ec2.instances.filter(InstanceIds=ids).terminate()
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Checking What Instances Are Running
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-----------------------------------
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Boto 3 collections come in handy when listing all your running instances as well. Every collection exposes a ``filter`` method that allows you to pass additional parameters to the underlying service API operation. The EC2 instances collection takes a parameter called ``Filters`` which is a list of names and values, for example::
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# Boto 2.x
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reservations = ec2_connection.get_all_reservations(
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filters={'instance-state-name': 'running'})
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for reservation in reservations:
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for instance in reservation.instances:
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print(instance.instance_id, instance.instance_type)
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# Boto 3
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# Use the filter() method of the instances collection to retrieve
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# all running EC2 instances.
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instances = ec2.instances.filter(
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Filters=[{'Name': 'instance-state-name', 'Values': ['running']}])
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for instance in instances:
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print(instance.id, instance.instance_type)
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Checking Health Status Of Instances
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-----------------------------------
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It is possible to get scheduled maintenance information for your running instances. At the time of this writing Boto 3 does not have a status resource, so you must drop down to the low-level client via ``ec2.meta.client``::
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# Boto 2.x
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for status in ec2_connection.get_all_instance_statuses():
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print(status)
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# Boto 3
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for status in ec2.meta.client.describe_instance_status()['InstanceStatuses']:
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print(status)
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Working with EBS Snapshots
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--------------------------
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Snapshots provide a way to create a copy of an EBS volume, as well as make new volumes from the snapshot which can be attached to an instance::
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# Boto 2.x
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snapshot = ec2_connection.create_snapshot('volume-id', 'Description')
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volume = snapshot.create_volume('us-west-2')
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ec2_connection.attach_volume(volume.id, 'instance-id', '/dev/sdy')
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ec2_connection.delete_snapshot(snapshot.id)
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# Boto 3
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snapshot = ec2.create_snapshot(VolumeId='volume-id', Description='description')
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volume = ec2.create_volume(SnapshotId=snapshot.id, AvailabilityZone='us-west-2a')
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ec2.Instance('instance-id').attach_volume(VolumeId=volume.id, Device='/dev/sdy')
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snapshot.delete()
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Creating a VPC, Subnet, and Gateway
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-----------------------------------
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Creating VPC resources in Boto 3 is very similar to Boto 2.x::
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# Boto 2.x
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vpc = vpc_connection.create_vpc('10.0.0.0/24')
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subnet = vpc_connection.create_subnet(vpc.id, '10.0.0.0/25')
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gateway = vpc_connection.create_internet_gateway()
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# Boto 3
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vpc = ec2.create_vpc(CidrBlock='10.0.0.0/24')
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subnet = vpc.create_subnet(CidrBlock='10.0.0.0/25')
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gateway = ec2.create_internet_gateway()
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Attaching and Detaching an Elastic IP and Gateway
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-------------------------------------------------
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Elastic IPs and gateways provide a way for instances inside of a VPC to communicate with the outside world::
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# Boto 2.x
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ec2_connection.attach_internet_gateway(gateway.id, vpc.id)
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ec2_connection.detach_internet_gateway(gateway.id, vpc.id)
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from boto.ec2.address import Address
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address = Address()
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address.allocation_id = 'eipalloc-35cf685d'
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address.associate('i-71b2f60b')
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address.disassociate()
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# Boto 3
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gateway.attach_to_vpc(VpcId=vpc.id)
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gateway.detach_from_vpc(VpcId=vpc.id)
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address = ec2.VpcAddress('eipalloc-35cf685d')
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address.associate('i-71b2f60b')
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address.association.delete()
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