Provide separate route tables for db/elasticache/redshift

[ghost]

Hi,

I've created separate route tables for the database, elasticache and redshift subnets.

Currently the db subnets automatically attach to the private subnet (which in turn is NAT'd out). This means the databases by default have a route to the internet.

This breaks the standard 3 tier dmz approach and I believe this shouldn't be the default. If users want to allow this, they can manually add in routes so their database subnets can be NAT'd out.

Let me know what you think and if you require any changes. Thanks for your hard work 😄

[nunofernandes]

+1

[antonbabenko]

Thanks for the PR!

Yes, it makes sense to make it slightly differently from how it is implemented now.

Few comments:

1. Make configurable if a user wants to use private route tables (as before, by default) OR create individual tables. This will require 3 new boolean variables - create_database_route_table, create_redshift_route_table, create_elasticache_route_table - all set to false by default.
2. Update documentation describing your use-case and show piece of code (either in README or make a new example in examples).

[antonbabenko]

Also, pre-commit install && pre-commit run -a will correct few minor styling errors.

[antonbabenko]

After long discussions and several PRs I believe this issue is now resolved and can be closed. See #132 (comment) for details.

[github-actions]

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