set CDK_DEFAULT_REGION env variable with aws configure command

Author: ksmin23

opensearch/cdk_stacks/vpc.py

@@ -2,6 +2,7 @@
 # -*- encoding: utf-8 -*-
 # vim: tabstop=2 shiftwidth=2 softtabstop=2 expandtab
 
+import os
 import aws_cdk as cdk
 
 from aws_cdk import (
@@ -23,27 +24,27 @@ def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
     # for example,
     # cdk -c vpc_name=your-existing-vpc syth
     #
-    # vpc_name = self.node.try_get_context("vpc_name") or "default"
-    # vpc = aws_ec2.Vpc.from_lookup(self, "OpenSearchDomainVpc",
-    #   is_default=True,
-    #   vpc_name=vpc_name)
-
-    #XXX: To use more than 2 AZs, be sure to specify the account and region on your stack.
-    #XXX: https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_ec2/Vpc.html
-    vpc = aws_ec2.Vpc(self, "OpenSearchDomainVpc",
-      max_azs=3,
-      gateway_endpoints={
-        "S3": aws_ec2.GatewayVpcEndpointOptions(
-          service=aws_ec2.GatewayVpcEndpointAwsService.S3
-        )
-      }
-    )
-
-    self.vpc = vpc
+    if str(os.environ.get('USE_DEFAULT_VPC', 'false')).lower() == 'true':
+      vpc_name = self.node.try_get_context("vpc_name") or "default"
+      self.vpc = aws_ec2.Vpc.from_lookup(self, "OpenSearchDomainVpc",
+        is_default=True,
+        vpc_name=vpc_name)
+    else:
+      #XXX: To use more than 2 AZs, be sure to specify the account and region on your stack.
+      #XXX: https://docs.aws.amazon.com/cdk/api/latest/python/aws_cdk.aws_ec2/Vpc.html
+      self.vpc = aws_ec2.Vpc(self, "OpenSearchDomainVpc",
+        max_azs=3,
+        gateway_endpoints={
+          "S3": aws_ec2.GatewayVpcEndpointOptions(
+            service=aws_ec2.GatewayVpcEndpointAwsService.S3
+          )
+        }
+      )
+
 
     #XXX: The Name field of every Export member must be specified and
     # consist only of alphanumeric characters,colons, or hyphens.
     cdk.CfnOutput(self, 'VPCID',
       value=self.vpc.vpc_id,
-      export_name='{}-VPCID'.format(self.stack_name))
+      export_name=f'{self.stack_name}-VPCID')