无法在AWS cdk中导入VPC

Question

[嗨，我正在研究AWS cdk。我试图创建一些资源，如ECS，SG，LB等。我想在资源中使用默认VPC。下面是我的代码。

app.py

     from aws_cdk import core
        from cdk_python.cdk_python_stack import CdkPythonStack
        app = core.App()
        CdkPythonStack(app, "cdk-python-1", env={'region': 'ap-southeast-2'})
        app.synth()

cdk_python_stack.py

    from aws_cdk import (
        aws_ec2 as ec2,
        aws_ecs as ecs,
        aws_elasticloadbalancingv2 as elbv2,
        aws_ecr as ecr,
        core,
    )

    class CdkPythonStack(core.Stack):


        def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
            super().__init__(scope, id, **kwargs)

    vpc = ec2.Vpc.from_lookup(scope = core.Construct, vpc_id='vpc-d45072b3', is_default=True, id="test" )

    cluster = ecs.Cluster(
        stack, "EcsCluster",
        vpc=vpc
    )

    cluster.add_capacity("DefaultAutoScalingGroup",
                         instance_type=ec2.InstanceType("t2.micro"),
                         key_name="MyNewEC2KeyPair",
                         desired_capacity=1)


    # create SG
    sg_elb  = ec2.SecurityGroup(stack, "MerchWebServicesLoadBalancerSecurityGroup",
        description= "Allow ssh access to ec2 instances",
        security_group_name= "MerchWebServicesLoadBalancerSecurityGroup",
        vpc= vpc
    );

    sg_elb.add_ingress_rule(
    peer = ec2.Peer.any_ipv4(),
    connection = ec2.Port.tcp(22)
    )



    # Create a task definition with placement constraints
    task_definition = ecs.Ec2TaskDefinition(
        stack, "TaskDef",
        # placement_constraints=[
        #     ecs.PlacementConstraint.distinct_instances()
        # ]
    )

    container = task_definition.add_container(
        "web",
        image=ecs.ContainerImage.from_registry("nginx:latest"),
        memory_limit_mib=256,
    )
    port_mapping = ecs.PortMapping(
        container_port=80,
        host_port=8080,
        protocol=ecs.Protocol.TCP
    )
    container.add_port_mappings(port_mapping)

    # Create Service
    service = ecs.Ec2Service(
        stack, "Service",
        cluster=cluster,
        task_definition=task_definition,
        security_group=sg_elb
    )


    lb = elbv2.ApplicationLoadBalancer(
        stack, "LB",
        vpc = vpc,
        internet_facing= True
    )

    listener = lb.add_listener(
        "PublicListener",
        port = 80,
        open = True
    )

    health_check = elbv2.HealthCheck(
        interval=core.Duration.seconds(60),
        path="/",
        timeout=core.Duration.seconds(5)
    )

    # Attach ALB to ECS Service
    listener.add_targets(
        "ECS",
        port=80,
        targets=[service],
        health_check=health_check,
    )

    service.add_placement_strategies(
        ecs.PlacementStrategy.packed_by(ecs.BinPackResource.MEMORY))
    service.add_placement_strategies(
        ecs.PlacementStrategy.spread_across(
            ecs.BuiltInAttributes.AVAILABILITY_ZONE))
    app.synth()

当我执行cdk合成器时，出现以下错误。

File "app.py", line 5, in <module>
    from cdk_python.cdk_python_stack import CdkPythonStack
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\cdk_python\cdk_python_stack.py", line 21, in <module>
    vpc = ec2.Vpc.from_lookup(scope = core.Construct, vpc_id='vpc-d45072b3', is_default=True, id="test" )
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\aws_cdk\aws_ec2\__init__.py", line 21474, in from_lookup
    return jsii.sinvoke(cls, "fromLookup", [scope, id, options])
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\jsii\_kernel\__init__.py", line 105, in wrapped
    return _recursize_dereference(kernel, fn(kernel, *args, **kwargs))
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\jsii\_kernel\__init__.py", line 292, in sinvoke
    args=_make_reference_for_native(self, args),
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\jsii\_kernel\providers\process.py", line 349, in sinvoke
    return self._process.send(request, InvokeResponse)
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\jsii\_kernel\providers\process.py", line 301, in send
    data = json.dumps(req_dict, default=jdefault).encode("utf8")
  File "C:\Program Files (x86)\Python37-32\lib\json\__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "C:\Program Files (x86)\Python37-32\lib\json\encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "C:\Program Files (x86)\Python37-32\lib\json\encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "C:\Users\ngodbole\Documents\MerchWebServices\CDKPython\.env\lib\site-packages\jsii\_kernel\providers\process.py", line 144, in jdefault
    raise TypeError("Don't know how to convert object to JSON: %r" % obj)
TypeError: Don't know how to convert object to JSON: <class 'aws_cdk.core.Construct'>

在构造函数中，我更改为

def init（自身，应用程序：core.Construct，id：str，** kwargs）->无：

现在我开始出现错误

NameError：未定义名称'self'

(.env) C:\Users\ngodbole\Documents\MerchWebServices\LocationCDK\LocationCDK>cdk synth
Traceback (most recent call last):
  File "app.py", line 5, in <module>
    from location_cdk.location_cdk_stack import LocationCdkStack
  File "C:\Users\ngodbole\Documents\MerchWebServices\LocationCDK\LocationCDK\location_cdk\location_cdk_stack.py", line 9, in <module>
    class LocationCdkStack(core.Stack):
  File "C:\Users\ngodbole\Documents\MerchWebServices\LocationCDK\LocationCDK\location_cdk\location_cdk_stack.py", line 15, in LocationCdkStack
    vpc = ec2.Vpc.from_lookup(self, "", is_default=True)
NameError: name 'self' is not defined
Subprocess exited with error 1

我正在尝试获取帐户中现有的默认VPC。我想在我的python cdk脚本创建的所有资源中使用相同的VPC。有人可以帮我解决这个问题吗？任何帮助将不胜感激。谢谢

Answer 1

将is_default参数设置为True即可获取默认VPC。

vpc = ec2.Vpc.from_lookup(self, "default_vpc", is_default=True)

您还需要按照此issue中所述在堆栈配置中显式设置帐户和区域。

CdkPythonStack(
  app=app, 
  id="cdk-python-1", 
  env={
    'account': os.environ['CDK_DEFAULT_ACCOUNT'], 
    'region': os.environ['CDK_DEFAULT_REGION']
  }
)