AWS Region-Specific Information Directory

Usage

Some information used in CDK Applications differs from one AWS region to another, such as service principals used in IAM policies, S3 static website endpoints, …

The RegionInfo class

The library offers a simple interface to obtain region specific information in the form of the RegionInfo class. This is the preferred way to interact with the regional information database:

# Get the information for "eu-west-1":
region = region_info.RegionInfo.get("eu-west-1")

# Access attributes:
region.s3_static_website_endpoint

The RegionInfo layer is built on top of the Low-Level API, which is described below and can be used to register additional data, including user-defined facts that are not available through the RegionInfo interface.

Low-Level API

This library offers a primitive database of such information so that CDK constructs can easily access regional information. The FactName class provides a list of known fact names, which can then be used with the RegionInfo to retrieve a particular value:

static_website = region_info.Fact.find("ap-northeast-1", region_info.FactName.S3_STATIC_WEBSITE_ENDPOINT)

Supplying new or missing information

As new regions are released, it might happen that a particular fact you need is missing from the library. In such cases, the Fact.register method can be used to inject FactName into the database:

@jsii.implements(region_info.IFact)
class MyFact:

region_info.Fact.register(MyFact())

Overriding incorrect information

In the event information provided by the library is incorrect, it can be overridden using the same Fact.register method demonstrated above, simply adding an extra boolean argument:

@jsii.implements(region_info.IFact)
class MyFact:

region_info.Fact.register(MyFact(), True)

If you happen to have stumbled upon incorrect data built into this library, it is always a good idea to report your findings in a GitHub issue, so we can fix it for everyone else!

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This module is part of the AWS Cloud Development Kit project.