Add ability to set location of credentials file with AWS_CREDENTIALS_…

[freimer]

…FILE environment variable

Sorry, I don't know how to add to the unit tests...

Signed-off-by: Fred Reimer [email protected]

[jamesls]

I agree we should add an env var for this value.

However, that env var name is already used to support pre-existing CLI tools (https://github.com/boto/botocore/blob/develop/botocore/credentials.py#L347) which is a different file with a different format. We'll need to choose another env name.

The java sdk uses AWS_CREDENTIAL_PROFILES_FILE (https://github.com/aws/aws-sdk-java/blob/master/aws-java-sdk-core/src/main/java/com/amazonaws/auth/profile/ProfilesConfigFile.java#L73), so perhaps we can just use that env var to be consistent.

[jamesls]

Sorry for the delay, I do like AWS_CREDENTIALS_FILE but as I mentioned it's already taken. I discussed this with the team and we'll just go with AWS_SHARED_CREDENTIALS_FILE.

[jamesls]

Merged in your pull request and renamed the env var to AWS_SHARED_CREDENTIALS_FILE. Tracking here: #623