---
# テンプレートのバージョンを指定
AWSTemplateFormatVersion: "version date"
# テンプレートの説明を指定
Description:
  String
# テンプレートに関する追加情報を指定
Metadata:
  template metadata
# スタック作成・更新時にテンプレートに渡す値を指定
Parameters:
  set of parameters
# スタック作成・更新時に利用するルールを指定
Rules:
  set of rules
# キーと関連する値のマッピングを指定
Mappings:
  set of mappings
# 制御条件を指定
Conditions:
  set of conditions
# テンプレートを処理する際に適用するマクロを1つ以上指定
Transform:
  set of transforms
# スタックリソースと、そのプロパティを指定
Resources:
  set of resources
# スタックのプロパティを確認すると返される値を指定
Outputs:
  set of outputs

pip3 install cfn-lint

% pip3 install cfn-lint
error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try brew install
    xyz, where xyz is the package you are trying to
    install.
    
    If you wish to install a Python library that isn't in Homebrew,
    use a virtual environment:
    
    python3 -m venv path/to/venv
    source path/to/venv/bin/activate
    python3 -m pip install xyz
    
    If you wish to install a Python application that isn't in Homebrew,
    it may be easiest to use 'pipx install xyz', which will manage a
    virtual environment for you. You can install pipx with
    
    brew install pipx
    
    You may restore the old behavior of pip by passing
    the '--break-system-packages' flag to pip, or by adding
    'break-system-packages = true' to your pip.conf file. The latter
    will permanently disable this error.
    
    If you disable this error, we STRONGLY recommend that you additionally
    pass the '--user' flag to pip, or set 'user = true' in your pip.conf
    file. Failure to do this can result in a broken Homebrew installation.
    
    Read more about this behavior here: <https://peps.python.org/pep-0668/>

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.

# 今回は「~/」直下に仮想環境を作成した
python3 -m venv ~/cfn-lint-python-venv
source ~/cfn-lint-python-venv/bin/activate
python3 -m pip install cfn-lint

# 書式： python3 -m venv ＜保存パス/保存名＞
# 書式： source ＜保存パス/保存名＞/bin/activate
# 書式： python3 -m pip install cfn-lint

% which cfn-lint
＜保存パス/保存名＞/bin/cfn-lint

"yaml.customTags": [
  "!Base64",
  "!Cidr sequence",
  "!And sequence",
  "!Equals sequence",
  "!If sequence",
  "!Not sequence",
  "!Or sequence",
  "!Condition",
  "!FindInMap sequence",
  "!GetAtt",
  "!GetAtt sequence",
  "!GetAZs",
  "!ImportValue",
  "!Join sequence",
  "!Select sequence",
  "!Split sequence",
  "!Sub",
  "!Sub sequence",
  "!Transform mapping",
  "!Ref"
]

Resources:
 〜省略〜

 PublicSubnetEgressVPCEndpointS3:
    Type: AWS::EC2::SecurityGroupEgress
    Properties:
      GroupId: !Ref PublicSubnetSG
      IpProtocol: -1
      DestinationPrefixListId: !GetAtt S3VPCEndpoint.PrefixList.PrefixListId # ＜＝左記の様な形で、VPCエンドポイントのプレフィックスリストIDを参照したかった

 〜省略〜