【Python】Cómo escribir una CommaDelimitedList en formato de lista (matriz) en samconfig.yml

📅 Creado: 2025/02/09, Actualizado: 2025/02/09 ⏱️ Tiempo estimado de lectura ~2 mins (379 palabras)

Al implementar usando samconfig.yml en la CLI de SAM, si escribe parámetros en el tipo CommaDelimitedList, deben escribirse como una cadena.
Si hay muchos elementos, escribirlo como una cadena lo hará más largo y menos legible.
Dado que CommaDelimitedList está escrito en formato de matriz en samconfig.yml, el proceso de conversión se implementó en Python, por lo que explicaremos cómo hacerlo.

Índice

Coding Standards and Prerequisites
Process for Converting a CommadelimitedList in List Format with samconfig.yml
(Extra) Generating a JSON File for –cli-input-json from a YAML File When Deploying CloudFormation

Coding Standards and Prerequisites

The Python scripts referenced in this article comply with PEP8.
They use flake8 for syntax checking and black for automatic formatting.
Code that must ignore checks for processing reasons includes # noqa .
The maximum line length ( max-line-length ) is set to 200 characters.
The Python runtime version is 3.12.1, and compatibility has been tested.

Process for Converting a CommadelimitedList in List Format with samconfig.yml

The required modules are:
argparse is part of the standard library, so no additional installation is needed.

pyyaml

The following Python script converts the value of parameter_overrides in samconfig.yml from array format to CommadelimitedList format. Save it with an appropriate Python filename (for example, transform_parameter_overrides.py ).
Since it is not possible to switch between SAM CLI options, please incorporate this script into your execution procedure or CI/CD pipeline.

import yaml
import argparse

def is_already_transformed(overrides):
    return all(isinstance(item, str) and "=" in item for item in overrides)

def transform_parameter_overrides(data):
    for key, value in data.items():
        if isinstance(value, dict) and "global" in value and "parameters" in value["global"]:
            parameters = value["global"]["parameters"]
            if "parameter_overrides" in parameters:
                if not is_already_transformed(parameters["parameter_overrides"]):
                    new_overrides = []
                    for override in parameters["parameter_overrides"]:
                        if isinstance(override, dict):
                            for k, v in override.items():
                                if isinstance(v, list):
                                    v = ",".join(v)
                                new_overrides.append(f"{k}={v}")
                    parameters["parameter_overrides"] = new_overrides
    return data

def main(input_file, output_file):
    with open(input_file, "r") as f:
        data = yaml.safe_load(f)

    transformed_data = transform_parameter_overrides(data)

    with open(output_file, "w") as f:
        yaml.dump(transformed_data, f, default_flow_style=False, sort_keys=False)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Transform parameter overrides in a YAML file.")
    parser.add_argument("--input-file", help="Path to the input YAML file.", default="samconfig.original.yml")
    parser.add_argument("--output-file", help="Path to the output YAML file.", default="samconfig.yml")
    args = parser.parse_args()

    main(args.input_file, args.output_file)

Here is an example of how to run the script. For example, to convert a samconfig.original.yml file written in List format to samconfig.yml :
The script uses these as default values, so you can run it without specifying any arguments.
If needed, specify the file path as an argument when running the script.

python transform_parameter_overrides.py

Below is an example of samconfig.original.yml . Converting this file will generate samconfig.yml .

version: 0.1
dev:
  global:
    parameters:
      parameter_overrides:
        - Environment: dev
        - Whitelist:
            # Windows Update
            # reference: https://learn.microsoft.com/en-us/windows-server/administration/windows-server-update-services/deploy/2-configure-wsus#211-configure-your-firewall-to-allow-your-first-wsus-server-to-connect-to-microsoft-domains-on-the-internet
            - .windowsupdate.microsoft.com
            - .update.microsoft.com
            - .windowsupdate.com
            - download.microsoft.com
            - .download.windowsupdate.com
            - wustat.windows.com
            - ntservicepack.microsoft.com
            - go.microsoft.com
            - dl.delivery.mp.microsoft.com
            - .delivery.mp.microsoft.com
            - .microsoft.com

Below is an example of the converted samconfig.yml . You can see that the value of Whitelist has been converted to CommadelimitedList format.

version: 0.1
dev:
  global:
    parameters:
      parameter_overrides:
      - Environment=dev
      - Whitelist=.windowsupdate.microsoft.com,.update.microsoft.com,.windowsupdate.com,download.microsoft.com,.download.windowsupdate.com,wustat.windows.com,ntservicepack.microsoft.com,go.microsoft.com,dl.delivery.mp.microsoft.com,.delivery.mp.microsoft.com,.microsoft.com

(Extra) Generating a JSON File for –cli-input-json from a YAML File When Deploying CloudFormation

When deploying CloudFormation, you can provide parameters as an external file and specify the JSON file with the --cli-input-json option. The process for generating this JSON file from a YAML file is as follows.
The required modules are:
argparse is part of the standard library, so no additional installation is needed.

pyyaml
json

The following Python script converts the value of Parameters in parameter.original.yml into a JSON file for use with --cli-input-json . Save it with an appropriate Python filename (for example, transform_parameters.py ).

import yaml
import json
import argparse

def transform_parameters(data):
    if "Parameters" in data:
        new_parameters = []
        for param in data["Parameters"]:
            for key, value in param.items():
                if isinstance(value, list):
                    value = ",".join(value)
                new_parameters.append({"ParameterKey": key, "ParameterValue": value})
        data["Parameters"] = new_parameters
    return data

def main(input_file, output_file):
    with open(input_file, "r") as f:
        data = yaml.safe_load(f)

    transformed_data = transform_parameters(data)

    with open(output_file, "w") as f:
        json.dump(transformed_data, f, indent=4)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Transform parameters in a YAML file.")
    parser.add_argument("--input-file", help="Path to the input YAML file.", default="parameter.original.yml")
    parser.add_argument("--output-file", help="Path to the output JSON file.", default="parameter.json")
    args = parser.parse_args()

    main(args.input_file, args.output_file)

Here is an example of how to run the script. For example, to convert parameter.original.yml in YAML format to parameter.json :
The script uses these as default values, so you can run it without specifying any arguments.
If needed, specify the file path as an argument when running the script.

python transform_parameters.py

Below is an example of parameter.original.yml . Converting this file will generate parameter.json .

Parameters:
  Environment:
    - dev
  Whitelist:
    - .windowsupdate.microsoft.com
    - .update.microsoft.com
    - .windowsupdate.com
    - download.microsoft.com
    - .download.windowsupdate.com
    - wustat.windows.com
    - ntservicepack.microsoft.com
    - go.microsoft.com
    - dl.delivery.mp.microsoft.com
    - .delivery.mp.microsoft.com
    - .microsoft.com

Below is an example of the converted parameter.json . You can see that the value of Parameters has been converted to the JSON file format required by --cli-input-json .

{
    "Parameters": [
        {
            "ParameterKey": "Environment",
            "ParameterValue": "dev"
        },
        {
            "ParameterKey": "Whitelist",
            "ParameterValue": ".windowsupdate.microsoft.com,.update.microsoft.com,.windowsupdate.com,download.microsoft.com,.download.windowsupdate.com,wustat.windows.com,ntservicepack.microsoft.com,go.microsoft.com,dl.delivery.mp.microsoft.com,.delivery.mp.microsoft.com,.microsoft.com"
        }
    ]
}