Parse an AWS ARN · Python practice

Parse an AWS ARN

Easy~10 min

An ARN has the form arn:partition:service:region:account-id:resource. The resource part may itself contain colons or slashes (e.g. function:my-fn:prod or role/admin).

Return a dictionary with keys partition, service, region, account, resource. Return None if the string doesn't start with arn: or has fewer than six parts.

Function

Implement parse_arn. Input: arn: str. Returns: dict | None.

Examples

>>> parse_arn('arn:aws:lambda:eu-west-1:123456789012:function:my-fn:prod')

{'region': 'eu-west-1', 'account': '123456789012', 'service': 'lambda', 'resource': 'function:my-fn:prod', 'partition': 'aws'}

>>> parse_arn('arn:aws:s3:::my-bucket/logs/*')

{'region': '', 'account': '', 'service': 's3', 'resource': 'my-bucket/logs/*', 'partition': 'aws'}

Details

Level: Functions, collections, parsing and straightforward scripting with a few edge cases.
Roles: AWS Engineer, Cloud Engineer, Security Engineer / DevSecOps
Topics: AWS SDK (Boto3-style), Parsing text, Strings
Tests: 2 public (run with Run), 3 hidden (graded on Submit)
Grading: Exact match of the return value