Add China arn compatibility. Use arn_prefix var for determinate which…

[gloterman]

Add China arn compatibility. Use arn_prefix var for determinate which ARN to use

what

• Adapt the AWS ARN prefix pour S3 bucket resource.
• Add a 'arn_prefix' local var in main.tf, the value is set related of the AWS region var.
• In the S3 bucket policy template, add the 'local.arn_prefix' var in prefix of resources.
• the 'arn_prefix' default value is set to 'arn:aws"

why

• Because for China region the ARN is 'arn:aws-cn', instead of 'arn:aws' for all other regions.
• It would be best if this module is available for all AWS regions.
• In my business case we deploy in many regions, included China.

references

• no reference, business case encountered in China region deployments.

[ericamador]

I believe #39 should now address this issue.

[osterman]

thanks @ericamador for the contribution. Yes #39 will replace this one as a generalied way to handle ARNs for any situation.

#39