AWS CloudFormation Template Snippets

This example shows the assembly of a UserData property using the Fn::Base64 and Fn::Join functions. The references MyValue and MyName are parameters that must be defined in the Parameters section of the template. The literal string Hello World is just another value this example passes in as part of the UserData.

"UserData" : {
    "Fn::Base64" : {
        "Fn::Join" : [ ",", [
            { "Ref" : "MyValue" },
            { "Ref" : "MyName" },
            "Hello World" ] ]
    }
}

This example shows the assembly of a UserData property using the Fn::Base64 and Fn::Join functions. It includes the AccessKey and SecretKey information. The references AccessKey and SecretKey are parameters that must be defined in the Parameters section of the template.

"UserData" : {
    "Fn::Base64" : {
        "Fn::Join" : [ "", [
            "ACCESS_KEY=", { "Ref" : "AccessKey" },
            "SECRET_KEY=", { "Ref" : "SecretKey" } ]
        ]
    }
}

The following example depicts a valid Parameters section declaration in which a single String type parameter is declared.

"Parameters" : {
    "UserName" : {
        "Type" : "String",
        "Default" : "nonadmin",
        "Description" : "Assume a vanilla user if no command-line spec provided"
    }
}

The following example depicts a valid Parameters section declaration in which a single String type parameter is declared. The AdminUserAccount parameter has a default of admin. The parameter value must have a minimum length of 1, a maximum length of 16, and contains alphabetic characters and numbers but must begin with an alphabetic character.

"Parameters" : {
    "AdminUserAccount": {
      "Default": "admin",
      "NoEcho": "true",
      "Description" : "The admin account username",
      "Type": "String",
      "MinLength": "1",
      "MaxLength": "16",
      "AllowedPattern" : "[a-zA-Z][a-zA-Z0-9]*"
    }
}

The following example depicts a valid Parameters section declaration in which a single Number type parameter is declared. The WebServerPort parameter has a default of 80 and a minimum value 1 and maximum value 65535.

"Parameters" : {
    "WebServerPort": {
      "Default": "80",
      "Description" : "TCP/IP port for the web server",
      "Type": "Number",
      "MinValue": "1",
      "MaxValue": "65535"
    }
}

The following example depicts a valid Parameters section declaration in which a single Number type parameter is declared. The WebServerPort parameter has a default of 80 and allows only values of 80 and 8888.

"Parameters" : {
    "WebServerPortLimited": {
      "Default": "80",
      "Description" : "TCP/IP port for the web server",
      "Type": "Number",
      "AllowedValues" : ["80", "8888"]
    }
}

The following example depicts a valid Parameters section declaration in which a single CommaDelimitedList type parameter is declared. The NoEcho property is set to TRUE, which will mask its value with asterisks (*****) in the cfn-describe-stacks output.

"Parameters" : {
    "UserRoles" : {
        "Type" : "CommaDelimitedList",
        "Default" : "guest,newhire",
        "NoEcho" : "TRUE"
    }
}

This example shows a parameter assignment based on the value returned from the psuedo parameter, "AWS::StackName".

"Parameters" : {
    "StackName" : {
        "Type" : "String",
        "Default" : { "Ref" : "AWS::StackName"}
    }
},

The following example depicts a valid Mapping section declaration that contains three mappings. The map, when matched with a mapping key of Stop, SlowDown, or Go, provides the RGB values assigned to the corresponding RGBColor attribute.

"Mappings" : {
    "LightColor" : {
        "Stop" : {
            "Description" : "red",
            "RGBColor" : "RED 255 GREEN 0 BLUE 0"
        },
        "SlowDown" : {
            "Description" : "yellow",
            "RGBColor" : "RED 255 GREEN 255 BLUE 0"
        },
        "Go" : {
            "Description" : "green",
            "RGBColor" : "RED 0 GREEN 128 BLUE 0"
        }
    }
},

The following example depicts a valid Description section declaration where the value is based on a literal string. This snippet can be for templates, parameters, resources, properties, or outputs.

"Description" : "Replace this value"

This example shows a output assignment based on a literal string.

"Outputs" : {
    "MyPhone" : {
        "Value" : "Please call 555-5555",
        "Description" : "A random message for cfn-describe-stacks"
    }
}

This example shows an Outputs section with two output assignments. One is based on a resource, and the other is based on a pseudo reference.

"Outputs" : {
   "SNSTopic" : { "Value" : { "Ref" : "MyNotificationTopic" } },
   "StackName" : { "Value" : { "Ref" : "AWS::StackName" } }
}        

This example shows an Outputs section with one output assignment. The Join function is used to concatenate the value, using a percent sign as the delimiter.

"Outputs" : {
    "MyOutput" : {
        "Value" : { "Fn::Join" :
            [ "%", [ "A-string", {"Ref" : "AWS::StackName" } ] ]
        }
    }
}

The following snippet depicts a valid Template Format Version section declaration.

"AWSTemplateFormatVersion" : "2010-09-09"

This example shows an AWS Tag property. You would specify this property within the Properties section of a resource. When the resource is created, it will be tagged with the tags you declare.

"Tags" : [
      {
        "Key" : "keyname1",
        "Value" : "value1"
      },
      {
        "Key" : "keyname2",
        "Value" : "value2"
      }
    ]
},