合成和引导如何协同工作如何配置 CDK 堆栈合成如何合成 CDK 堆栈合成的默认工作原理自定义 CDK 堆栈合成

配置和执行 CDK 堆栈合成

在部署 AWS 云开发工具包 (AWS CDK) 堆栈之前，必须先对其进行合成。堆栈合成是从 CDK 堆栈生成 AWS CloudFormation 模板和部署构件的过程。模板和构件称为云程序集。部署云程序集后即可在 AWS 上预置资源。有关部署的工作原理的更多信息，请参阅 AWS CDK 部署的工作原理。

合成和引导如何协同工作

为了正确部署 CDK 应用程序，合成过程中生成的 CloudFormation 模板必须正确指定引导过程中创建的资源。因此，引导和合成必须相辅相成，才能成功部署：

引导是为 AWS CDK 部署设置 AWS 环境的一次性过程。它会在您的环境中配置 CDK 用于部署的特定 AWS 资源。这些资源通常被称为引导资源。有关引导的说明，请参阅引导环境以用于 AWS CDK。
合成过程中生成的 CloudFormation 模板包含有关要使用哪些引导资源的信息。在合成期间，CDK CLI 并不具体知道 AWS 环境是如何引导的。相反，CDK CLI 会根据您为每个 CDK 堆栈配置的合成器生成 CloudFormation 模板。要成功部署，合成器必须生成引用要使用的正确引导资源的 CloudFormation 模板。

CDK 自带能够协同工作的默认合成器和引导配置。如果您对其中一个进行自定义，则必须对另一个应用相关的自定义。

如何配置 CDK 堆栈合成

您可以使用 Stack 实例的 synthesizer 属性配置 CDK 堆栈合成。此属性指定如何合成 CDK 堆栈。您提供实现 IStackSynthesizer 或 IReusableStackSynthesizer 的类的实例。每次将资源添加到堆栈或合成堆栈时，都会调用其方法。以下是在堆栈中使用此属性的基本示例：

例

您还可以使用 App 实例的 defaultStackSynthesizer 属性为 CDK 应用程序中的所有 CDK 堆栈配置合成器：

例

TypeScript


import { App, Stack, DefaultStackSynthesizer } from 'aws-cdk-lib';

const app = new App({
  // Configure for all stacks in this app
  defaultStackSynthesizer: new DefaultStackSynthesizer({
    /* ... */
  }),
});

JavaScript


const { App, Stack, DefaultStackSynthesizer } = require('aws-cdk-lib');

const app = new App({
  // Configure for all stacks in this app
  defaultStackSynthesizer: new DefaultStackSynthesizer({
    /* ... */
  }),
});

Python


from aws_cdk import App, Stack, DefaultStackSynthesizer

app = App(
    default_stack_synthesizer=DefaultStackSynthesizer(
        # Configure for all stacks in this app
        # ...
    )
)

Java


import software.amazon.awscdk.App;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.DefaultStackSynthesizer;

public class Main {
    public static void main(final String[] args) {
        App app = new App(AppProps.builder()
            // Configure for all stacks in this app
            .defaultStackSynthesizer(DefaultStackSynthesizer.Builder.create().build())
            .build()
        );
    }
}

C#


using Amazon.CDK;
using Amazon.CDK.Synthesizers;

namespace MyNamespace
{
    sealed class Program
    {
        public static void Main(string[] args)
        {
            var app = new App(new AppProps
            {
                // Configure for all stacks in this app
                DefaultStackSynthesizer = new DefaultStackSynthesizer(new DefaultStackSynthesizerProps
                {
                    // ...
                })
            });
        }
    }
}

Go


package main

import (
    "github.com/aws/aws-cdk-go/awscdk/v2"
    "github.com/aws/constructs-go/constructs/v10"
    "github.com/aws/jsii-runtime-go"
)

func main() {
    defer jsii.Close()

    app := awscdk.NewApp(&awscdk.AppProps{
        // Configure for all stacks in this app
        DefaultStackSynthesizer: awscdk.NewDefaultStackSynthesizer(&awscdk.DefaultStackSynthesizerProps{
            // ...
        }),
    })
}

AWS CDK 默认使用 `DefaultStackSynthesizer。如果您未配置合成器，则将使用此合成器。

如果您不修改引导，例如更改引导堆栈或模板，则不必修改堆栈合成。您甚至不必提供合成器。CDK 将使用默认 DefaultStackSynthesizer 类配置 CDK 堆栈合成，以便与引导堆栈正确交互。

如何合成 CDK 堆栈

要合成 CDK 堆栈，请使用 AWS CDK 命令行界面 (AWS CDK CLI) 的 cdk synth 命令。有关此命令的更多信息，包括可与此命令一起使用的选项，请参阅 cdk synthesize。

如果 CDK 应用程序包含单个堆栈，或者要合成所有堆栈，则无需提供 CDK 堆栈名称作为参数。默认情况下，CDK CLI 会将 CDK 堆栈合成到 AWS CloudFormation 模板中。每个堆栈的 json 格式的模板将保存到 cdk.out 目录中。如果您的应用程序包含单个堆栈，则会将 yaml 格式的模板打印到 stdout 中。以下是示例：


$ cdk synth
Resources:
  CDKMetadata:
    Type: AWS::CDK::Metadata
    Properties:
      Analytics: v2:deflate64:H4sIAAAAAAAA/unique-identifier
    Metadata:
      aws:cdk:path: CdkAppStack/CDKMetadata/Default
    Condition: CDKMetadataAvailable
    ...

如果 CDK 应用程序包含多个堆栈，则可以提供堆栈的逻辑 ID 以合成单个堆栈。以下是示例：


$ cdk synth MyStackName

如果您没有合成堆栈并运行 cdk deploy，CDK CLI 将在部署前自动合成堆栈。

合成的默认工作原理

AWS CloudFormation 模板中生成的逻辑 ID

合成 CDK 堆栈以生成 CloudFormation 模板时，逻辑 ID 是从以下源生成的，格式为 construct-pathconstruct-IDunique-hash：

构造路径：指向 CDK 应用程序中构造的完整路径。此路径不包括 L1 构造的 ID（始终为 Resource 或 Default）以及它所属的顶级堆栈的 ID。
构造 ID：实例化构造时作为第二个参数提供的 ID。

唯一哈希值 – AWS CDK 会使用确定性哈希算法生成 8 个字符的唯一哈希值。此唯一哈希值有助于确保模板中的逻辑 ID 值是唯一的。此哈希值生成的确定性行为可确保每次执行合成时，为每个构造生成的逻辑 ID 值保持不变。只有在您修改特定的构造值（例如构造的 ID 或其路径）时，哈希值才会改变。

逻辑 ID 最多可包含 255 个字符。因此，如有必要，AWS CDK 将截断构造路径和构造 ID，以保持在该限制之内。

以下是定义 Amazon Simple Storage Service（Amazon S3）存储桶的示例构造。在本例中，我们将 myBucket 作为构造的 ID 传递：

例

TypeScript


import * as cdk from 'aws-cdk-lib';
import { Construct} from 'constructs';
import * as s3 from 'aws-cdk-lib/aws-s3';

export class MyCdkAppStack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // Define the S3 bucket
    new s3.Bucket(this, 'myBucket', {
      versioned: true,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });
  }
}

JavaScript


const cdk = require('aws-cdk-lib');
const s3 = require('aws-cdk-lib/aws-s3');

class MyCdkAppStack extends cdk.Stack {

  constructor(scope, id, props) {
    super(scope, id, props);

    new s3.Bucket(this, 'myBucket', {
      versioned: true,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });
  }
}

module.exports = { MyCdkAppStack }

Python


import aws_cdk as cdk
from constructs import Construct
from aws_cdk import Stack
from aws_cdk import aws_s3 as s3

class MyCdkAppStack(Stack):
  def __init__(self, scope: Construct, construct_id: str, **kwargs) - None:
    super().__init__(scope, construct_id, **kwargs)

    s3.Bucket(self, 'MyBucket',
      versioned=True,
      removal_policy=cdk.RemovalPolicy.DESTROY
    )

Java


package com.myorg;

import software.constructs.Construct;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;
import software.amazon.awscdk.services.s3.Bucket;
import software.amazon.awscdk.services.s3.BucketProps;
import software.amazon.awscdk.RemovalPolicy;

public class MyCdkAppStack extends Stack {
    public MyCdkAppStack(final Construct scope, final String id) {
        this(scope, id, null);
    }

    public MyCdkAppStack(final Construct scope, final String id, final StackProps props) {
        super(scope, id, props);

        Bucket.Builder.create(this, "myBucket")
            .versioned(true)
            .removalPolicy(RemovalPolicy.DESTROY)
            .build();
    }
}

C#


using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.S3;

namespace MyCdkApp
{
    public class MyCdkAppStack : Stack
    {
        public MyCdkAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
        {
            new Bucket(this, "myBucket", new BucketProps
            {
                Versioned = true,
                RemovalPolicy = RemovalPolicy.DESTROY
            });
        }
    }
}

Go


package main

import (
    "github.com/aws/aws-cdk-go/awscdk/v2"
    "github.com/aws/aws-cdk-go/awscdk/v2/awss3"
    "github.com/aws/constructs-go/constructs/v10"
    "github.com/aws/jsii-runtime-go"
)

type MyCdkAppStackProps struct {
    awscdk.StackProps
}

func NewMyCdkAppStack(scope constructs.Construct, id string, props *MyCdkAppStackProps) awscdk.Stack {
    var sprops awscdk.StackProps
    if props != nil {
        sprops = props.StackProps
    }
    stack := awscdk.NewStack(scope, id, sprops)

    awss3.NewBucket(stack, jsii.String("myBucket"), awss3.BucketProps{
      Versioned: jsii.Bool(true),
      RemovalPolicy: awscdk.RemovalPolicy_DESTROY,
    })

    return stack
}

// ...

运行 cdk synth 时，会生成格式为 myBucketunique-hash 的逻辑 ID。下面是生成的 AWS CloudFormation 中此资源的示例：


Resources:
  myBucket5AF9C99B:
    Type: AWS::S3::Bucket
    Properties:
      VersioningConfiguration:
        Status: Enabled
    UpdateReplacePolicy: Delete
    DeletionPolicy: Delete
    Metadata:
      aws:cdk:path: S3BucketAppStack/myBucket/Resource

下面是名为 Bar 的自定义构造的示例，它会定义 Amazon S3 存储桶。Bar 构造在其路径中包含自定义构造 Foo：

例

TypeScript


import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as s3 from 'aws-cdk-lib/aws-s3';

// Define the Bar construct
export class Bar extends Construct {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    // Define an S3 bucket inside of Bar
    new s3.Bucket(this, 'Bucket', {
       versioned: true,
       removalPolicy: cdk.RemovalPolicy.DESTROY,
      } );
  }
}

// Define the Foo construct
export class Foo extends Construct {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    // Create an instance of Bar inside Foo
    new Bar(this, 'Bar');
  }
}

// Define the CDK stack
export class MyCustomAppStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // Instantiate Foo construct in the stack
    new Foo(this, 'Foo');
  }
}

JavaScript


const cdk = require('aws-cdk-lib');
const s3 = require('aws-cdk-lib/aws-s3');
const { Construct } = require('constructs');

// Define the Bar construct
class Bar extends Construct {
  constructor(scope, id) {
    super(scope, id);

    // Define an S3 bucket inside of Bar
    new s3.Bucket(this, 'Bucket', {
      versioned: true,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });
  }
}

// Define the Foo construct
class Foo extends Construct {
  constructor(scope, id) {
    super(scope, id);

    // Create an instance of Bar inside Foo
    new Bar(this, 'Bar');
  }
}

// Define the CDK stack
class MyCustomAppStack extends cdk.Stack {
  constructor(scope, id, props) {
    super(scope, id, props);

    // Instantiate Foo construct in the stack
    new Foo(this, 'Foo');
  }
}

module.exports = { MyCustomAppStack }

Python


import aws_cdk as cdk
from constructs import Construct
from aws_cdk import (
    Stack,
    aws_s3 as s3,
    RemovalPolicy,
)

# Define the Bar construct
class Bar(Construct):
    def __init__(self, scope: Construct, id: str) - None:
        super().__init__(scope, id)

        # Define an S3 bucket inside of Bar
        s3.Bucket(self, 'Bucket',
            versioned=True,
            removal_policy=RemovalPolicy.DESTROY
        )

# Define the Foo construct
class Foo(Construct):
    def __init__(self, scope: Construct, id: str) - None:
        super().__init__(scope, id)

        # Create an instance of Bar inside Foo
        Bar(self, 'Bar')

# Define the CDK stack
class MyCustomAppStack(Stack):
    def __init__(self, scope: Construct, id: str, **kwargs) - None:
        super().__init__(scope, id, **kwargs)

        # Instantiate Foo construct in the stack
        Foo(self, 'Foo')

Java

In my-custom-app/src/main/java/com/myorg/Bar.java:


package com.myorg;

import software.constructs.Construct;
import software.amazon.awscdk.services.s3.Bucket;
import software.amazon.awscdk.services.s3.BucketProps;
import software.amazon.awscdk.RemovalPolicy;

public class Bar extends Construct {
    public Bar(final Construct scope, final String id) {
        super(scope, id);

        // Define an S3 bucket inside Bar
        Bucket.Builder.create(this, "Bucket")
            .versioned(true)
            .removalPolicy(RemovalPolicy.DESTROY)
            .build();
    }
}

In my-custom-app/src/main/java/com/myorg/Foo.java:


package com.myorg;

import software.constructs.Construct;

public class Foo extends Construct {
    public Foo(final Construct scope, final String id) {
        super(scope, id);

        // Create an instance of Bar inside Foo
        new Bar(this, "Bar");
    }
}

In my-custom-app/src/main/java/com/myorg/MyCustomAppStack.java:


package com.myorg;

import software.constructs.Construct;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;

public class MyCustomAppStack extends Stack {
    public MyCustomAppStack(final Construct scope, final String id, final StackProps props) {
        super(scope, id, props);

        // Instantiate Foo construct in the stack
        new Foo(this, "Foo");
    }

    // Overload constructor in case StackProps is not provided
    public MyCustomAppStack(final Construct scope, final String id) {
        this(scope, id, null);
    }
}

C#


using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.S3;

namespace MyCustomApp
{
    // Define the Bar construct
    public class Bar : Construct
    {
        public Bar(Construct scope, string id) : base(scope, id)
        {
            // Define an S3 bucket inside Bar
            new Bucket(this, "Bucket", new BucketProps
            {
                Versioned = true,
                RemovalPolicy = RemovalPolicy.DESTROY
            });
        }
    }

    // Define the Foo construct
    public class Foo : Construct
    {
        public Foo(Construct scope, string id) : base(scope, id)
        {
            // Create an instance of Bar inside Foo
            new Bar(this, "Bar");
        }
    }

    // Define the CDK Stack
    public class MyCustomAppStack : Stack
    {
        public MyCustomAppStack(Construct scope, string id, StackProps props = null) : base(scope, id, props)
        {
            // Instantiate Foo construct in the stack
            new Foo(this, "Foo");
        }
    }
}

Go


package main

import (
	"github.com/aws/aws-cdk-go/awscdk/v2"
	"github.com/aws/aws-cdk-go/awscdk/v2/awss3"
	"github.com/aws/constructs-go/constructs/v10"
	"github.com/aws/jsii-runtime-go"
)

// Define the Bar construct
type Bar struct {
	constructs.Construct
}

func NewBar(scope constructs.Construct, id string) constructs.Construct {
	bar := constructs.NewConstruct(scope, id)

	// Define an S3 bucket inside Bar
	awss3.NewBucket(bar, jsii.String("Bucket"), awss3.BucketProps{
		Versioned:     jsii.Bool(true),
		RemovalPolicy: awscdk.RemovalPolicy_DESTROY,
	})

	return bar
}

// Define the Foo construct
type Foo struct {
	constructs.Construct
}

func NewFoo(scope constructs.Construct, id string) constructs.Construct {
	foo := constructs.NewConstruct(scope, id)

	// Create an instance of Bar inside Foo
	NewBar(foo, "Bar")

	return foo
}

// Define the CDK Stack
type MyCustomAppStackProps struct {
	awscdk.StackProps
}

func NewMyCustomAppStack(scope constructs.Construct, id string, props *MyCustomAppStackProps) awscdk.Stack {
	stack := awscdk.NewStack(scope, id, props.StackProps)

	// Instantiate Foo construct in the stack
	NewFoo(stack, "Foo")

	return stack
}

// Define the CDK App
func main() {
	app := awscdk.NewApp(nil)

	NewMyCustomAppStack(app, "MyCustomAppStack", MyCustomAppStackProps{
		StackProps: awscdk.StackProps{},
	})

	app.Synth(nil)
}

运行 cdk synth 时，会生成格式为 FooBarBucketunique-hash 的逻辑 ID。下面是生成的 AWS CloudFormation 中此资源的示例：


Resources:
  FooBarBucketBA3ED1FA:
    Type: AWS::S3::Bucket
    Properties:
      VersioningConfiguration:
        Status: Enabled
    UpdateReplacePolicy: Delete
    DeletionPolicy: Delete
    # ...

自定义 CDK 堆栈合成

如果默认的 CDK 合成行为不符合您的需求，则可以自定义 CDK 合成。为此，您可以修改 DefaultStackSynthesizer、使用其他可用的内置合成器或创建自己的合成器。有关说明，请参阅自定义 CDK 堆栈合成。

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文档惯例

定义 L2 构造的权限

自定义 CDK 合成