Cloudformation:在映射键中替换变量

Question

我有一个这样定义的角色:

AWSTemplateFormatVersion: "2010-09-09"

Parameters:
AWSAccountId:
Type: String
OidcProvider:
Type: String
AppNamespace:
Type: String

AppServiceAccountName:
Type: String

Resources:
CloudWatchRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
-
Effect: "Allow"
Principal:
Federated:
- !Join ["", [ "arn:aws:iam::", !Ref AWSAccountId, ":oidc-provider/", !Ref OidcProvider ] ]
Action:
- "sts:AssumeRoleWithWebIdentity"
Condition:
StringEquals:
!Sub ${OidcProvider}:sub: "system:serviceaccount:${AppNamespace}:${AppServiceAccountName}"

我的挑战是如何替换StringEquals部分中的参数。一切都在Federated块中工作。但是在StringEquals块中，我不能让join或sub工作。

按照代码，我得到错误消息:

An error occurred (ValidationError) when calling the CreateStack operation: 
Template format error[/Resources/CloudWatchRole/Properties/AssumeRolePolicyDocument/
Statement/0/Condition/StringEquals] map keys must be strings; received a map instead

所以，我想我的问题是如何在映射的键中替换变量。UserData也没帮上忙。

Answer 1

你的问题是在Federated上而不是在StringEquals上。Federated值需要为string，但您将其定义为Map。请在!Join之前删除-。

AWSTemplateFormatVersion: "2010-09-09"
Parameters:
AWSAccountId:
Type: String
OidcProvider:
Type: String
AppNamespace:
Type: String
AppServiceAccountName:
Type: String
Resources:
CloudWatchRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument: !Sub
- |
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Federated": "${IamOidcProviderArn}"
},
"Action": "sts:AssumeRoleWithWebIdentity",
"Condition": {
"StringEquals": {
"${OidcProvider}:sub": "system:serviceaccount:${AppNamespace}:${AppServiceAccountName}"
}
}
}
]
}
- IamOidcProviderArn: !Join
- ''
- - 'arn:aws:iam::'
- !Ref AWSAccountId
- ':oidc-provider/'
- !Ref OidcProvider
OidcProvider: !Ref OidcProvider
AppNamespace: !Ref AppNamespace
AppServiceAccountName: !Ref AppServiceAccountName