AWS security groups must be allowed to have cyclic dependencies between each other (v0.3.1)

[delitescere]

Security groups are applied to instances. If one instance associated with a security group wants to connect to another instance associated with the same the security group, the security group must have an allow rule with a source of itself (meaning "other instances associated with this group").

The following must be allowed:

resource "aws_security_group" "public" {
...
}

resource "aws_security_group" "private" {
...
  ingress {
    protocol = "tcp"
    from_port = 1024
    to_port = 65535
    security_groups = ["${aws_security_group.public.id}", "${aws_security_group.private.id}"]
  }
}

However we get the following error:

$ terraform apply
Error configuring: Error building module graph 'security_group': The dependency graph is not valid:

* Cycle: aws_security_group.private

Additionally, non-self cycles must be allowed as two security groups may have allow rules from each other.

Ref: http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_SecurityGroups.html#VPCSecurityGroups
"Instances associated with a security group can't talk to each other unless you add rules allowing it (exception: the default security group has these rules by default)."

[delitescere]

RTFM Josh.

self=true (when it works...)