cfn-docgen 0.4.0

Document generator from cfn template files.

cfn-docgen

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cfn-docgen is a command line tool that generates the table formatted CloudFormation(cfn) definition file from the original, yaml or json formatted template file.

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Example

If you have a yaml cfn template file like below,

AWSTemplateFormatVersion: 2010-09-09
Description: sample vpc template
Parameters:
  EnvType:
    Description: env type
    Type: String
    Default: dev
Resources: 
  VPC:
    Type: AWS::EC2::VPC
    Metadata:
      UserNotes:
        ResourceNote: This is a note for VPC resource
        PropNotes:
          CidrBlock: This is a note for CidrBlock prop
          Tags[1].Value: This is a note for Value prop of 2nd Tags list prop
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: true
      Tags:
        - Key: ENV
          Value: !Ref EnvType
        - Key: Name
          Value: SampleVpc

you can generate a content like below.

ResourceId	ResourceType	ResourceNote	Property	Value	UserNote	Required	Type	UpdateType	Description	IsOmittable	Filename
VPC	AWS::EC2::VPC	This is a note for VPC resource	CidrBlock	10.0.0.0/16	This is a note for CidrBlock prop	False	String	Immutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	EnableDnsHostnames			False	Boolean	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	True	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	EnableDnsSupport	True		False	Boolean	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	InstanceTenancy			False	String	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	True	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Ipv4IpamPoolId			False	String	Immutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	True	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Ipv4NetmaskLength			False	Integer	Immutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	True	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Tags			False	List of Tag	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Tags[0].Key	ENV		True	String	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Tags[0].Value	{'Ref': 'EnvType'}		True	String	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Tags[1].Key	Name		True	String	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html	False	cfn.yaml
VPC	AWS::EC2::VPC	This is a note for VPC resource	Tags[1].Value	SampleVpc	This is a note for Value prop of 2nd Tags list prop	True	String	Mutable	http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html	False	cfn.yaml

The key features of this tool are,

• All of the properties of each resource, including ones you omit to define, are listed in generated file.
  • In the example above, properties EnableDnsHostnames, InstanceTenancy, Ipv4IpamPoolId, and Ipv4NetmaskLength are omitted in original cfn template file, but listed in generated file.

• You can add custom notes for each resource and property at Metadata section in each resource.
  • You can add custom note for a resource at Metadata.UserNotes.ResourceNote
  • You can add custom notes for properties at Metadata.UserNotes.PropNotes.{PropertyName}
    • For nested or list properties, you can specify PropertyName like Tags[1].Value .
• Not only Resources section in cfn template, this tool can also generate definitions of other sections, including Parameters, Mappings, and Outputs and resource policies like CreationPolicy, UpdatePolicy, UpdateReplacePlocy, DeletionPolicy, and DependsOn.
• You can generate files as excel, md, csv, or html format.
  • In excel format, all of definitions are separated by sheets.
  • In other format, all of definitions are separated by files.

For more example, see sample directory.

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Basic command usage

$ cfn-docgen --in sample/sample-template.json --fmt xlsx

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How to use

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CLI(Linux/Windows)

• Prerequirements
  • python>=3.8

$ pip install cfn-docgen

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Docker

We also provide cfn-docgen as Docker image.

# pull image from DockerHub
$ docker pull horietakehiro/cfn-docgen:latest

# local directory(before)
$ tree /tmp/sample/
/tmp/sample/
└── sample-template.json

0 directories, 1 files

# run as command
$ docker run \
  -v /tmp/sample/:/tmp/ \
  -v ~/.cfn-docgen/:/root/.cfn-docgen/ \
  horietakehiro/cfn-docgen:latest --in /tmp/sample-template.json --fmt xlsx

# local directory(after)
$ tree /tmp/sample/
/tmp/sample/
├── sample-template.json
└── sample-template.xlsx

0 directories, 2 files

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GUI(Windows only)

We also provide cfn-docgen as GUI application here.

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serverless

You can also use cfn-docgen on AWS Cloud as serverless application.

You can deploy resources at AWS Serverless Application Repository.

Once deployed, tha S3 bucket named cfn-docgen-${AWS::AccountId}-${AWS::Region} is created on your account.

When you upload cfn template json/yaml files at templates/ folder of the bucket, cfn-docgen-serverless automatically will be triggered and generates excel docments for them.

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API

You can directry handle data as pandas DataFrame.

import pandas as pd
from cfn_docgen import cfn_def
cfn_template = cfn_def.CfnTemplate("./sample/sample-template.json")
property_df = cfn_template.to_df(cfn_template.resources, "Resources_Property")
assert isinstance(property_df, pd.DataFrame)

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