Add method accessible_from to test security group rules

temyers commented 7 years ago

Added accessible_from? to security groups and RDS instances.

The semantics for security groups are:

There is an ingress rule where the CIDR matches, or is a superset of the supplied CIDR range.

The semantics for RDS instances is slightly different:

Is there a security group which satisfies the CIDR
If the CIDR is for a public subnet, is the database publicly accessible

There are additional semantics that I consider out of scope, since they should probably be tested separately:

If the CIDR is an internal address, is it within the CIDR of the associated VPC (if the RDS instance is in a VPC)
VPC Peering CIDRs

temyers commented 7 years ago

@SaltwaterC This PR is ready to go.
I'll give you the opportunity to review before I merge.

temyers commented 7 years ago

@SaltwaterC Would you be able to push a release?

SaltwaterC commented 7 years ago

Sure. I'll need to tag the release and bump the version. I'll do it once I get to my office as I don't have the gem environment configured on this box.

SaltwaterC commented 7 years ago

Release pushed. Thank you for taking your contributions.

SaltwaterC / serverspec-aws

Add method accessible_from to test security group rules #9