S3 - Moving role_arn from credentials to config

[popei69]

Enhancement Suggestion / Bug Report

Going further in #175, the fix seems to rely on credentials file only for source_profile and role_arn fields.

However, AWS suggests to use config to setup source_profile and role_arn. Source: Assuming an IAM Role in the AWS CLI

Steps which explain the enhancement or reproduce the bug

1. Setup AWS with source_profile and role_arn setup in config file as expected by AWS from their documentation.
2. Run Rome

Current behavior

Access Denied

Why would the enhancement be useful to most users

Using config file instead of credentials file for this specific request would avoid to support duplicated configuration between those two files.

Rome version:

0.21.0.58 - Romam uno die non fuisse conditam.

OS and version:

macOS 10.14.4

[tmspzz]

Yes, it relies on ~/.aws/credentials. I was under the impression that was the correct place but apparently it's not. I'll address this asap.

[popei69]

@blender I had a look into it and created a PR for it #190.

It ran in my local environment with having the source_profile and role_arn only in config file instead of credentials. I'm not expert into Haskell, please let me know if I miss anything.

Thanks

[tmspzz]

@popei69 Thanks for your contribution, the new version is out https://github.com/blender/Rome/releases/tag/v0.23.0.60

[popei69]

@blender No worries, happy to help! Thanks for the quick release.