JavaScript，如何只运行一次代码？

Question

我正在从 AWS 机密管理器动态保存我的.env内容，但我想在服务器启动后保存所有值。 应该采取什么方法？

我正在使用打字稿：

getSecrets("key").then((keys: any) => {
 const originalKeys = JSON.parse(keys);
 for (const key in originalKeys) {
  if (originalKeys.hasOwnProperty(key)) {
    appendFileSync(
      __dirname + "/.env",
      `${key}='${originalKeys[key]}'\n`
    );
  }
}

Answer 1

您可以使用布尔值来记住代码是否已执行。 像这样的东西：

let excecuted = false;
if (!excecuted) {
  excecuted = true;
  getSecrets("key").then((keys: any) => {
    const originalKeys = JSON.parse(keys);
    for (const key in originalKeys) {
      if (originalKeys.hasOwnProperty(key)) {
        appendFileSync(__dirname + "/.env", `${key}='${originalKeys[key]}'\n`);
      }
    }
  });
}

Answer 2

我正在从 AWS 机密管理器中动态保存我的 .env 内容。

为什么要将它们保存在.env中？ 您可以将它们保存在配置对象中，并且可以在需要它们的任何地方重复使用它们。

const AWS = require('aws-sdk'); 

class SecretsManager {
    
    let #config = null;
    async #getSecret (secretName, region){
        const config = { region : region }
        var secret, decodedBinarySecret;
        let secretsManager = new AWS.SecretsManager(config);
        try {
            let secretValue = await secretsManager.getSecretValue({SecretId: secretName}).promise();
            if ('SecretString' in secretValue) {
                return secret = secretValue.SecretString;
            } else {
                let buff = new Buffer(secretValue.SecretBinary, 'base64');
                return decodedBinarySecret = buff.toString('ascii');
            }
        } catch (err) {
            if (err.code === 'DecryptionFailureException')
                // Secrets Manager can't decrypt the protected secret text using the provided KMS key.
                // Deal with the exception here, and/or rethrow at your discretion.
                throw err;
            else if (err.code === 'InternalServiceErrorException')
                // An error occurred on the server side.
                // Deal with the exception here, and/or rethrow at your discretion.
                throw err;
            else if (err.code === 'InvalidParameterException')
                // You provided an invalid value for a parameter.
                // Deal with the exception here, and/or rethrow at your discretion.
                throw err;
            else if (err.code === 'InvalidRequestException')
                // You provided a parameter value that is not valid for the current state of the resource.
                // Deal with the exception here, and/or rethrow at your discretion.
                throw err;
            else if (err.code === 'ResourceNotFoundException')
                // We can't find the resource that you asked for.
                // Deal with the exception here, and/or rethrow at your discretion.
                throw err;
        }
    } 

    static async getSecretValues() {
        const secretName = '<secretsName>';
        const region = '<Region>';
       try {
       if (!this.#config) { 
          return this.#config;
       } else {
          this.#config = await this.#getSecret(secretName, region);
       }
      } catch (e) {
        console.log(e);
      }
    }
}
module.exports = SecretsManager;

在您的文件中，您可以使用它：

const SecretsManager = require('./SecretsManager.js');

const secret = SecretsManager.getSecretValues();

您可以在此处查看更多详细信息。