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# 用于在 St CloudFormation ep Functions 中创建工作流程
在本教程中，您将使用创建 AWS Lambda 函数 AWS CloudFormation。您将使用 CloudFormation 控制台和 YAML 模板来创建*堆栈*（IAM 角色、Lambda 函数和状态机）。然后，您将使用 Step Functions 控制台来启动状态机执行。
有关更多信息，请参阅《*AWS CloudFormation 用户指南》中的使用 CloudFormation *[模板](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-guide.html)和`[AWS::StepFunctions::StateMachine](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-stepfunctions-statemachine.html)`资源。
## 第 1 步：设置您的 CloudFormation 模板
在使用[示例模板](#lambda-state-machine-cfn-step-2)之前，您应该了解如何声明 CloudFormation 模板的不同部分。
### 为 Lambda 创建 IAM 角色
定义与 Lambda 函数的 IAM 角色关联的信任策略。以下示例使用 YAML 或 JSON 定义信任策略。
------
#### [ YAML ]
```
LambdaExecutionRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service: lambda.amazonaws.com
Action: "sts:AssumeRole"
```
------
#### [ JSON ]
```
"LambdaExecutionRole": {
"Type": "AWS::IAM::Role",
"Properties": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "lambda.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
}
```
------
### 创建 Lambda 函数
为将打印 `Hello World` 消息的 Lambda 函数定义以下属性。
**重要**
确保您的 Lambda 函数与 AWS 区域 状态机位于同一个 AWS 账户下。
------
#### [ YAML ]
```
MyLambdaFunction:
Type: "AWS::Lambda::Function"
Properties:
Handler: "index.handler"
Role: !GetAtt [ LambdaExecutionRole, Arn ]
Code:
ZipFile: |
exports.handler = (event, context, callback) => {
callback(null, "Hello World!");
};
Runtime: "nodejs12.x"
Timeout: "25"
```
------
#### [ JSON ]
```
"MyLambdaFunction": {
"Type": "AWS::Lambda::Function",
"Properties": {
"Handler": "index.handler",
"Role": {
"Fn::GetAtt": [
"LambdaExecutionRole",
"Arn"
]
},
"Code": {
"ZipFile": "exports.handler = (event, context, callback) => {\n callback(null, \"Hello World!\");\n};\n"
},
"Runtime": "nodejs12.x",
"Timeout": "25"
}
},
```
------
### 创建用于状态机执行的 IAM 角色
定义与状态机执行的 IAM 角色关联的信任策略。
------
#### [ YAML ]
```
StatesExecutionRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: "Allow"
Principal:
Service:
- !Sub states.${AWS::Region}.amazonaws.com
Action: "sts:AssumeRole"
Path: "/"
Policies:
- PolicyName: StatesExecutionPolicy
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action:
- "lambda:InvokeFunction"
Resource: "*"
```
------
#### [ JSON ]
```
"StatesExecutionRole": {
"Type": "AWS::IAM::Role",
"Properties": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": [
{
"Fn::Sub": "states.${AWS::Region}.amazonaws.com"
}
]
},
"Action": "sts:AssumeRole"
}
]
},
"Path": "/",
"Policies": [
{
"PolicyName": "StatesExecutionPolicy",
"PolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"lambda:InvokeFunction"
],
"Resource": "*"
}
]
}
}
]
}
},
```
------
### 创建 Lambda 状态机
定义 Lambda 状态机。
------
#### [ YAML ]
```
MyStateMachine:
Type: "AWS::StepFunctions::StateMachine"
Properties:
DefinitionString:
!Sub
- |-
{
"Comment": "A Hello World example using an AWS Lambda function",
"StartAt": "HelloWorld",
"States": {
"HelloWorld": {
"Type": "Task",
"Resource": "${lambdaArn}",
"End": true
}
}
}
- {lambdaArn: !GetAtt [ MyLambdaFunction, Arn ]}
RoleArn: !GetAtt [ StatesExecutionRole, Arn ]
```
------
#### [ JSON ]
```
"MyStateMachine": {
"Type": "AWS::StepFunctions::StateMachine",
"Properties": {
"DefinitionString": {
"Fn::Sub": [
"{\n \"Comment\": \"A Hello World example using an AWS Lambda function\",\n \"StartAt\": \"HelloWorld\",\n \"States\": {\n \"HelloWorld\": {\n \"Type\": \"Task\",\n \"Resource\": \"${lambdaArn}\",\n \"End\": true\n }\n }\n}",
{
"lambdaArn": {
"Fn::GetAtt": [
"MyLambdaFunction",
"Arn"
]
}
}
]
},
"RoleArn": {
"Fn::GetAtt": [
"StatesExecutionRole",
"Arn"
]
}
}
}
```
------
## 步骤 2：使用 CloudFormation 模板创建 Lambda 状态机
了解 CloudFormation 模板的组件后，就可以将它们组合在一起并使用模板创建 CloudFormation 堆栈。
### 创建 Lambda 状态机
1. 将以下示例数据复制到名为 `MyStateMachine.yaml`（适用于 YAML 示例）或 `MyStateMachine.json`（适用于 JSON）的文件中。
------
#### [ YAML ]
```
AWSTemplateFormatVersion: "2010-09-09"
Description: "An example template with an IAM role for a Lambda state machine."
Resources:
LambdaExecutionRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service: lambda.amazonaws.com
Action: "sts:AssumeRole"
MyLambdaFunction:
Type: "AWS::Lambda::Function"
Properties:
Handler: "index.handler"
Role: !GetAtt [ LambdaExecutionRole, Arn ]
Code:
ZipFile: |
exports.handler = (event, context, callback) => {
callback(null, "Hello World!");
};
Runtime: "nodejs12.x"
Timeout: "25"
StatesExecutionRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: "Allow"
Principal:
Service:
- !Sub states.${AWS::Region}.amazonaws.com
Action: "sts:AssumeRole"
Path: "/"
Policies:
- PolicyName: StatesExecutionPolicy
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action:
- "lambda:InvokeFunction"
Resource: "*"
MyStateMachine:
Type: "AWS::StepFunctions::StateMachine"
Properties:
DefinitionString:
!Sub
- |-
{
"Comment": "A Hello World example using an AWS Lambda function",
"StartAt": "HelloWorld",
"States": {
"HelloWorld": {
"Type": "Task",
"Resource": "${lambdaArn}",
"End": true
}
}
}
- {lambdaArn: !GetAtt [ MyLambdaFunction, Arn ]}
RoleArn: !GetAtt [ StatesExecutionRole, Arn ]
```
------
#### [ JSON ]
```
{
"AWSTemplateFormatVersion": "2010-09-09",
"Description": "An example template with an IAM role for a Lambda state machine.",
"Resources": {
"LambdaExecutionRole": {
"Type": "AWS::IAM::Role",
"Properties": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "lambda.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
}
},
"MyLambdaFunction": {
"Type": "AWS::Lambda::Function",
"Properties": {
"Handler": "index.handler",
"Role": {
"Fn::GetAtt": [
"LambdaExecutionRole",
"Arn"
]
},
"Code": {
"ZipFile": "exports.handler = (event, context, callback) => {\n callback(null, \"Hello World!\");\n};\n"
},
"Runtime": "nodejs12.x",
"Timeout": "25"
}
},
"StatesExecutionRole": {
"Type": "AWS::IAM::Role",
"Properties": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": [
{
"Fn::Sub": "states.${AWS::Region}.amazonaws.com"
}
]
},
"Action": "sts:AssumeRole"
}
]
},
"Path": "/",
"Policies": [
{
"PolicyName": "StatesExecutionPolicy",
"PolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"lambda:InvokeFunction"
],
"Resource": "*"
}
]
}
}
]
}
},
"MyStateMachine": {
"Type": "AWS::StepFunctions::StateMachine",
"Properties": {
"DefinitionString": {
"Fn::Sub": [
"{\n \"Comment\": \"A Hello World example using an AWS Lambda function\",\n \"StartAt\": \"HelloWorld\",\n \"States\": {\n \"HelloWorld\": {\n \"Type\": \"Task\",\n \"Resource\": \"${lambdaArn}\",\n \"End\": true\n }\n }\n}",
{
"lambdaArn": {
"Fn::GetAtt": [
"MyLambdaFunction",
"Arn"
]
}
}
]
},
"RoleArn": {
"Fn::GetAtt": [
"StatesExecutionRole",
"Arn"
]
}
}
}
}
}
```
------
1. 打开 [CloudFormation](https://console.aws.amazon.com/cloudformation/home) 控制台并选择**创建堆栈**。
1. 在**选择模板**页面上，选择**将模板上传到 Amazon S3**。选择您的 `MyStateMachine` 文件，然后选择**下一步**。
1. 在**指定详细信息**页面上，为**堆栈名称**输入 `MyStateMachine`，然后选择**下一步**。
1. 在**选项**页面上，选择**下一步**。
1. 在**审核**页面上，选择**我确认， CloudFormation 可能创建 IAM 资源。**，然后选择**创建**。
CloudFormation 开始创建`MyStateMachine`堆栈并显示 **CREATE\$1IN\$1** PROGRESS 状态。在此过程完成后， CloudFormation 将显示 **CREATE\$1COMPLETE** 状态。
1. （可选）要显示您的堆栈中的资源，请选择堆栈，然后选择**资源**选项卡。
## 第 3 步：启动状态机执行
在创建您的 Lambda 状态机后，可以开始执行。
### 启动状态机执行
1. 打开 [Step Functions 控制台](https://console.aws.amazon.com/states/home)，然后选择你使用创建的状态机的名称 CloudFormation。
1. 在***MyStateMachine-ABCDEFGHIJ1K***页面上，选择 “**新建执行**”。
此时将显示**新执行**页面。
1. （可选）输入自定义执行名称，以便覆盖生成的默认执行名称。
**非 ASCII 名称和日志记录**
Step Functions 对于状态机、执行、活动和标签接受包含非 ASCII 字符的名称。由于此类字符会 CloudWatch 阻止亚马逊记录数据，因此我们建议您仅使用 ASCII 字符，这样您就可以跟踪 Step Functions 的指标。
1. 选择**开始执行**。
此时将启动新的状态机执行，并显示一个说明正在运行的执行的新页面。
1. （可选）在**执行详细信息**中，查看**执行状态**以及**已开始**和**已关闭**时间戳。
1. 要查看执行结果，请选择**输出**。