Design your application with dynamic subnets¶
The Section Design your application with static subnets in multiple regions shows how to define multiple subnets for a network explicitly. However, users may not want to define the subnets explicitly. In such a case, the Cloud Create will auto-generate one subnet for each region dynamically as follows:
Step 1. Design¶
Design an application with two computes connecting to the same
Private
network. The Private network has no subnets.Click on the
Private
network and specify the cidr:10.0.0.0/24
.Connect the first compute (e.g.,
Compute
) to thePublic
network.
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Figure 1. Auto-generated subnet example¶
Step 2. Deploy¶
Case 1. Two computes in the same region¶
Go to Deploy / Google / Configure cloud provider.
Choose the zone for the two computes in the same region
europe-west1
(e.g., chooseeurope-west1-b
andeurope-west1-c
forCompute
andCompute_2
, respectively).
Expected result¶
Google Cloud requires one region has at least one subnet. The designer auto-generates one subnet
Private_subnet_europe_west1
for the regioneurope-west1
in thePrivate
network.The subnet has the same cidr of the
Private
network (i.e.,10.0.0.0/24
).Both computes
Compute
andCompute-2
connect to this subnet.
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Figure 2. Private_subnet_europe_west1 is auto-generated for two computes in one region¶
The
routing_mode
of thePrivate
network is auto set toREGIONAL
(if not set) since all computes are in the same region.
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Figure 3. The routing_mode is auto set to REGIONAL¶
Case 2. Two computes in different regions¶
Go to Deploy / Google / Configure cloud provider.
Choose the zone for the computes in two different regions (e.g., choose the zone
europe-north1-a
andeurope-west1-c
forCompute
andCompute_2
, respectively).
Expected result¶
Google Cloud requires one region has at least one subnet. Because we have two regions, the designer auto-generates two subnets for the region
europe-north1
andeurope-west1
.The cidr of the
Private
network (i.e.,10.0.0.0/24
) is auto subnetting in two equal ranges for each subnet (i.e.,10.0.0.0/25
and10.0.0.128/25
).Two computes connect to two separated subnets in different regions.
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Figure 4. Two subnets are auto-generated for two regions¶
The
routing_mode
of thePrivate
network is auto set toGLOBAL
(if not set) so that the two computes from different regions can access each other via the internal IP address.
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Figure 5. The routing_mode is auto set to GLOBAL¶
Tip
Auto-generated subnet is useful if you cannot decide the location of the computes at the design time (i.e., whether the computes are co-located in one or in different regions) but at the deployment time. In such a case, Cloud Create will transform the topology before the deployment for you.