Question

尝试在Fn :: FindInMap中使用Fn :: Join，如下所示：

"SubnetId": {
    "Fn::FindInMap": [
        {
            "Ref": "OrganizationName"
        },
        "AZ",
        {
            "Fn::Join": [
                "",
                [
                    {
                        "Ref": "Environment"
                    },
                    {
                        "Ref": "Member1AZ"
                    }
                ]
            ]
        }
    ]
}

OrganizationName，Environment和Member1AZ都是参数。基本上它应该连接到我的映射并生成，例如：

"SubnetId" : { "Fn::FindInMap" : [ "Organization2", "AZ", "prod1c" ]}

但是，它似乎没有将Fn :: Join的输出作为Fn :: FindInMap上的单个实体，如果我硬编码模板的那一部分，它会正确验证。

A client error (ValidationError) occurred when calling the ValidateTemplate operation: Template error: every Fn::FindInMap object requires three parameters, the map name, map key and the attribute for return value

我的映射如下：

Mappings" : {
      "OrganizationDefaults" : {
            "AZ" : {
                "prod1a" : "subnet-foobar1",
                "qa1a" : "subnet-foobar2",
                "prod1c" : "subnet-foobar3",
                "qa1c" : "subnet-foobar4"
            }
      },
      "OrganizationTwo" : {
            "AZ" : {
                "prod1a" : "subnet-foobar5",
                "qa1a" : "subnet-foobar6",
                "prod1c" : "subnet-foobar7",
                "qa1c" : "subnet-foobar8"
            }
      },
},

任何人都可以提供帮助吗，或者之前不得不做类似的事情？我需要为列出的任何组织使用相同的模板，所以如果我能做对，Mappings应该为我解决这个问题。

Answer 1

虽然我同意@Jason，在您的情况下，您的地图布局的重构是最适合您的解决方案，但有些情况下CloudFormation中地图的2D限制可能会受到限制，因此我将在此处发布可能的解决方案

截至本文发布之日，Fn::FindInMap内在函数仅支持以下嵌套函数：

Fn::FindInMap
Ref

使用Join会给您上面发布的稍微有点神秘的错误。但是，因为您可以嵌套FindInMap调用，所以您可以通过创建另一个查找映射来实现地图的“第三维”：

Mappings" : {
  "OrganizationDefaults" : {
        "AZ" : {
            "prod1a" : "subnet-foobar1",
            "qa1a" : "subnet-foobar2",
            "prod1c" : "subnet-foobar3",
            "qa1c" : "subnet-foobar4"
        }
  },
  "OrganizationTwo" : {
        "AZ" : {
            "prod1a" : "subnet-foobar5",
            "qa1a" : "subnet-foobar6",
            "prod1c" : "subnet-foobar7",
            "qa1c" : "subnet-foobar8"
        }
  },
  "EnvMemberMap" : {
        "prod": {
            "1a" : "prod1a",
            "1c" : "prod1c",
        },
        "qa": {
            "1a" : "qa1a",
            "1c" : "qa1c",
        }    
  }
},

然后像这样执行地图检索：

"SubnetId": {
    "Fn::FindInMap": [
        {
            "Ref": "OrganizationName"
        },
        "AZ",
        {
            "Fn::FindInMap": [
                "EnvMemberMap",
                {
                    "Ref": "Environment"
                },
                {
                    "Ref": "Member1AZ"
                }
            ]
        }
    ]
}

Answer 2

我建议你重构你的映射以避免嵌套的Fn :: Join。

Mappings" : {
      "OrganizationDefaults" : {
            "1a" : {
                "prod" : "subnet-foobar1",
                "qa" : "subnet-foobar2"
            },
            "1c"
                "prod" : "subnet-foobar3",
                "qa" : "subnet-foobar4"
            }
      },
      "OrganizationTwo" : {
            "1a" : {
                "prod" : "subnet-foobar5",
                "qa" : "subnet-foobar6"
            },
            "1c" : {
                "prod" : "subnet-foobar7",
                "qa" : "subnet-foobar8"
            }
      },
},

这简化了您的参考。

"SubnetId" : { "Fn::FindInMap" : [ { "Ref" : "OrganizationName" }, { "Ref" : "Member1AZ" }, { "Ref" : "Environment" }]}

AWS Cloudformation：Fn ::在Fn :: FindInMap语句中加入？

2 个答案: