https://github.com/drewsonne/cfn-json-to-yaml

Convert JSON CloudFormation templates to YAML.
https://github.com/drewsonne/cfn-json-to-yaml

Last synced: about 1 month ago
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Convert JSON CloudFormation templates to YAML.

• Host: GitHub
• URL: https://github.com/drewsonne/cfn-json-to-yaml
• Owner: drewsonne
• License: lgpl-3.0
• Created: 2017-03-20T20:22:39.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2017-03-27T09:56:20.000Z (over 7 years ago)
• Last Synced: 2024-09-26T10:13:07.123Z (3 months ago)
• Language: Python
• Size: 438 KB
• Stars: 4
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG
  • License: LICENSE

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# cfnjsontoyaml

Convert JSON CloudFormation templates to the new YAML syntax. This

includes converting all `Fn::*` and `Ref` JSON functions to `!*` yaml

node type functions.

In addition, cfnjsontoyaml tries to make a best guess at when

 `Fn::Join` functions should automatically be converted to `!Sub`.

### Convert Long JSON to compact YAML

This utility not only converts from JSON to yaml, it will use the new

short yaml syntax, and attempt to convert `Fn::Join` to `!Sub`,

resulting in shorter, more compact syntax.

For example, and IAM role can be converted from 127 lines of JSON

cloudformation to 30 lines of yaml.

![docs/images/diagram.png](docs/images/diagram.png)

## Usage

`cfn-json-to-yaml` reads either from standard in, or takes the first

argument as the template to ingest and prints the yaml converted

template to stdout.

    $ pip install cfnjsontoyaml

    $ cat my_template.json | cfn-json-to-yaml

## Examples

### APIGateway Method with lambda proxy

In some cases, we can halve the number of lines, while still maintaining readability.

Here, we convert 48 lines of JSON to 19 lines of YAML.

#### JSON

    {

      "Resources": {

        "MappingReferenceMethod": {

          "Type": "AWS::ApiGateway::Method",

          "DependsOn": [

            "LambdaInvokePermissionMappingReference"

          ],

          "Properties": {

            "RestApiId": {

              "Ref": "RestApi"

            },

            "ResourceId": {

              "Ref": "MappingReferenceResource"

            },

            "HttpMethod": "POST",

            "AuthorizationType": "NONE",

            "ApiKeyRequired": true,

            "RequestParameters": {

              "method.request.header.x-api-key": true

            },

            "Integration": {

              "Type": "AWS_PROXY",

              "Uri": {

                "Fn::Join": [

                  "",

                  [

                    "arn:aws:apigateway:",

                    {

                      "Ref": "AWS::Region"

                    },

                    ":lambda:path/2015-03-31/functions/",

                    {

                      "Fn::GetAtt": [

                        "LambdaFunctionMappingReference",

                        "Arn"

                      ]

                    },

                    "/invocations"

                  ]

                ]

              },

              "IntegrationHttpMethod": "POST",

              "PassthroughBehavior": "when_no_templates"

            }

          }

        }

      }

    }

#### YAML

    ---

    Resources:

      MappingReferenceMethod:

        Type: AWS::ApiGateway::Method

        Properties:

          ApiKeyRequired: true

          AuthorizationType: NONE

          HttpMethod: POST

          Integration:

            IntegrationHttpMethod: POST

            PassthroughBehavior: when_no_templates

            Type: AWS_PROXY

            Uri: !Sub "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${LambdaFunctionMappingReference.Arn}/invocations"

          RequestParameters:

            method.request.header.x-api-key: true

          ResourceId: !Ref "MappingReferenceResource"

          RestApiId: !Ref "RestApi"

        DependsOn:

        - LambdaInvokePermissionMappingReference

## Problems

There are a wide range of combinations for functions in cloudformation.

If you come across a template which does not render correctly, please

try and isolate the fragment of json which is causing issues, and

create an [issue in github](https://github.com/drewsonne/cfn-json-to-yaml/issues/new) .

If you'd like to be a bit more helpful, you can fork the repository,

create a branch, and add a json/yaml snippet to https://github.com/drewsonne/cfn-json-to-yaml/tree/master/tests/resources/fragments

with the next sequential number. The smaller the json/yaml snippet

you can provide the quicker I can fix it. :-)