Improving AWS subnet docs.

docs/roles/aws/aws_ec2_autoscale_cluster.md

@@ -36,6 +36,8 @@ aws_ec2_autoscale_cluster:
   vpc_id: vpc-XXXX # One of vpc_id or vpc_name is mandatory.
   # vpc_name: example-vpc
   subnets:
+    # If rds.rds.true is set and you are creating an RDS instance then you must use at least two AZs, this is hard requirement.
+    # This means your region and environment must also have a minimum of two subnets - see `aws_vpc_subnet`
     # - az: a
     #   cidr: "10.0.3.0/26"
     - az: b

docs/roles/aws/aws_rds.md

@@ -19,6 +19,7 @@ aws_rds:
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
   multi_az: true
+  # You must provide at least two subnets in two different AZs, even for single AZ deployments.
   subnets:
     - subnet-aaaaaaaa
     - subnet-bbbbbbbb

docs/roles/aws/aws_vpc_subnet.md

@@ -11,6 +11,7 @@ aws_vpc_subnet:
   # vpc_name: example-vpc
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
+  # If you intend to have RDS instances you must provide at least two subnets.
   subnets:
     - cidr_block: "10.0.0.0/24"
       # ipv6_cidr_block: "1" # This will create something like xxxx:xxxx:xxxx:xxyy::/64 where yy is created using the ansible.utils.ipsubnet filter automatically - DO NOT DEFINE IF IPV6 IS NOT REQUIRED

roles/aws/aws_ec2_autoscale_cluster/README.md

@@ -36,6 +36,8 @@ aws_ec2_autoscale_cluster:
   vpc_id: vpc-XXXX # One of vpc_id or vpc_name is mandatory.
   # vpc_name: example-vpc
   subnets:
+    # If rds.rds.true is set and you are creating an RDS instance then you must use at least two AZs, this is hard requirement.
+    # This means your region and environment must also have a minimum of two subnets - see `aws_vpc_subnet`
     # - az: a
     #   cidr: "10.0.3.0/26"
     - az: b

roles/aws/aws_ec2_autoscale_cluster/defaults/main.yml

@@ -17,6 +17,8 @@ aws_ec2_autoscale_cluster:
   vpc_id: vpc-XXXX # One of vpc_id or vpc_name is mandatory.
   # vpc_name: example-vpc
   subnets:
+    # If rds.rds.true is set and you are creating an RDS instance then you must use at least two AZs, this is hard requirement.
+    # This means your region and environment must also have a minimum of two subnets - see `aws_vpc_subnet`
     # - az: a
     #   cidr: "10.0.3.0/26"
     - az: b

roles/aws/aws_rds/README.md

@@ -19,6 +19,7 @@ aws_rds:
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
   multi_az: true
+  # You must provide at least two subnets in two different AZs, even for single AZ deployments.
   subnets:
     - subnet-aaaaaaaa
     - subnet-bbbbbbbb

roles/aws/aws_rds/defaults/main.yml

@@ -2,6 +2,7 @@ aws_rds:
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
   multi_az: true
+  # You must provide at least two subnets in two different AZs, even for single AZ deployments.
   subnets:
     - subnet-aaaaaaaa
     - subnet-bbbbbbbb

roles/aws/aws_vpc_subnet/README.md

@@ -11,6 +11,7 @@ aws_vpc_subnet:
   # vpc_name: example-vpc
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
+  # If you intend to have RDS instances you must provide at least two subnets.
   subnets:
     - cidr_block: "10.0.0.0/24"
       # ipv6_cidr_block: "1" # This will create something like xxxx:xxxx:xxxx:xxyy::/64 where yy is created using the ansible.utils.ipsubnet filter automatically - DO NOT DEFINE IF IPV6 IS NOT REQUIRED

roles/aws/aws_vpc_subnet/defaults/main.yml

@@ -3,6 +3,7 @@ aws_vpc_subnet:
   # vpc_name: example-vpc
   aws_profile: "{{ _aws_profile }}"
   region: "{{ _aws_region }}"
+  # If you intend to have RDS instances you must provide at least two subnets.
   subnets:
     - cidr_block: "10.0.0.0/24"
       # ipv6_cidr_block: "1" # This will create something like xxxx:xxxx:xxxx:xxyy::/64 where yy is created using the ansible.utils.ipsubnet filter automatically - DO NOT DEFINE IF IPV6 IS NOT REQUIRED