我可以在状态机定义文件中使用全局变量吗

Question

我正在使用AWS SAM进行一个无服务器项目，该项目由lambda和状态机资源组成(请参阅下面的SAM模板(。我想知道是否有一种方法可以定义"；Global"；变量，就像我们可以使用SAM模板的Globals一样。

我想这样做的原因是为了缩短我的状态机定义。现在，有一些州对我的Fargate任务使用了完全相同的属性，例如NetworkConfiguration块：

definition.asl.json

{
"StartAt": "Generate Config",
"States": {
"Generate Config": {
"Type": "Task",
"Resource": "${GenerateConfigFunctionArn}",
"Next": "ETL"
},
"ETL": {
"Type": "Task",
"Resource": "arn:aws:states:::ecs:runTask.sync",
"Next": "ETL",
"Parameters": {
"LaunchType": "FARGATE",
"Cluster": "arn:aws:ecs:region:11111111:cluster/clustername",
"TaskDefinition": "arn:aws:ecs:region:11111111:task-definition/taskdef",
"NetworkConfiguration": {
"AwsvpcConfiguration": {
"Subnets": [
"subnet-00d610225d369486e"
],
"SecurityGroups": [
"sg-016650ff9ecd28a9a"
],
"AssignPublicIp": "ENABLED"
}
},
"Overrides": {
"ContainerOverrides": [
{
"Name": "Phase-1-start",
"Environment": [
{
"Name": "COMMAND",
"Value": "etl"
}
]
}
]
}
}
},
"Well_Calc": {
"Type": "Task",
"Resource": "arn:aws:states:::ecs:runTask.sync",
"End": true,
"Parameters": {
"LaunchType": "FARGATE",
"Cluster": "arn:aws:ecs:region:11111111:cluster/clustername",
"TaskDefinition": "arn:aws:ecs:region:11111111:task-definition/taskdef",
"NetworkConfiguration": {
"AwsvpcConfiguration": {
"Subnets": [
"subnet-00d610225d369486e"
],
"SecurityGroups": [
"sg-016650ff9ecd28a9a"
],
"AssignPublicIp": "ENABLED"
}
},
"Overrides": {
"ContainerOverrides": [
{
"Name": "Phase-1-start",
"Environment": [
{
"Name": "COMMAND",
"Value": "calculation"
}
]
}
]
}
}
}
}
}

SAM template

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Resources:
MySAMPOC:
Type: AWS::Serverless::StateMachine
Properties:
DefinitionUri: stateMachine/definition.asl.json
DefinitionSubstitutions:
GenerateConfigFunctionArn: !GetAtt GenerateConfigFunction.Arn
GenerateConfigFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: functions/generate_config
Handler: app.lambda_handler
Runtime: python3.8

状态机定义是否支持使用全局参数(或类似参数(？

Answer 1

Globals目前不支持AWS::Serverless::StateMachine。您可以考虑的一些替代选项：

• 对某些值使用DefinitionSubstitutions：https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-resource-statemachine.html#sam-状态机定义替换
• Step Function现在在开发工具中支持YAML，所以从JSON切换到YAML至少可以节省一点缩进和大括号。https://aws.amazon.com/about-aws/whats-new/2021/03/aws-step-functions-adds-tooling-support-for-yaml/
• 使用CDK定义您的状态机。您可以创建封装公共属性的自定义构造。显然这不是SAM，但您可以将SAM资源与CDK应用程序集成，或者考虑将部分应用程序迁移到CDK。https://docs.aws.amazon.com/cdk/api/latest/docs/aws-stepfunctions-readme.html