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86 lines
2.6 KiB
ReStructuredText
86 lines
2.6 KiB
ReStructuredText
Setting region programmatically in Boto3
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:date: 2015-04-24 14:07
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:author: Russell Ballestrini
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:tags: Code, DevOps, Python, AWS
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:slug: setting-region-programmatically-in-boto3
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:status: published
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:summary:
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At work I'm looking into the possibility of porting parts of our AWS
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automation codebase from Boto2 to Boto3. We desire to perform this port
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because Boto2's record and result pagination appears defective.
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I started to familiarize myself with Boto3 by using the Interactive Python interpreter.
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Here I show myself trying to connect to the RDS AWS endpoint following the docs:
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.. code-block:: python
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>>> import boto3
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>>> rds = boto3.client('rds')
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Traceback (most recent call last):
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...
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NoRegionError: You must specify a region.
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What, No region? OK - how do I set a region?
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Well it turns out the docs want you to configure a region in a config file.
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This will not work for me, I need to set the region programatically...
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So after stumbling around in the botocore source code I found the
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following solutions.
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**Solution 1 - Set region\_name when creating client:**
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.. code-block:: python
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>>> import boto3
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>>> rds = boto3.client('rds', region_name='us-west-2')
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**Solution 2 - Set default region\_name on the session:**
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.. code-block:: python
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>>> import boto3
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>>> rds = boto3.setup_default_session(region_name='us-west-2')
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>>> rds = boto3.client('rds')
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It seems Boto3 has two types of interfaces, clients and resources.
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Clients:
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return description objects and appear lower level.
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Description objects seem like AWS XML responses transformed into Python Dicts/Lists.
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Resources:
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return higher level Python objects and like Instances with stop/start methods.
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At a quick glance, both clients and resources seem to properly implement
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pagination automatically!
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.. code-block:: python
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>>> # client interface.
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>>> ec2 = boto3.client('ec2', region_name='us-west-2')
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>>> idesc = ec2.describe_instances()
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>>> len(idesc['Reservations'])
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273
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>>> idesc['ResponseMetadata']
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{'HTTPStatusCode': 200, 'RequestId': '7e431ff7-xxxx-xxxx-xxxx-xxxxxxxxxxxxx'}
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>>> # resource interface.
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>>> ec2 = boto3.resource('ec2', region_name='us-west-2')
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>>> for instance in ec2.instances.all():
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>>> print instance, instance.tags
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That all for now!
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You should read my other Boto related posts for tricks to impress your friends. : )
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* `Filtering AWS resources with Boto3 </filtering-aws-resources-with-boto3/>`_
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* `Working with botocores AWS config </working-with-botocores-awsconfig/>`_
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.. contents::
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