How to use @azure/keyvault-secrets - 3 common examples

Key Vault - Secrets
        Identity - Credential
        ------------------------
        1) Set a secret
        2) Get that secret
        3) Delete that secret (Clean up the resource)
        `);

    // EnvironmentCredential expects the following three environment variables:
    // * AZURE_TENANT_ID: The tenant ID in Azure Active Directory
    // * AZURE_CLIENT_ID: The application (client) ID registered in the AAD tenant
    // * AZURE_CLIENT_SECRET: The client secret for the registered application
    const credential = new EnvironmentCredential();
    const url = process.env["AZURE_PROJECT_URL"] || "";

    KeyVaultSecrets.client = new SecretsClient(url, credential);

    KeyVaultSecrets.secretName = `MySecretName-${uuidv1()}`;
    KeyVaultSecrets.secretValue = "MySecretValue";

    try {
      await KeyVaultSecrets.setSecret();
      await KeyVaultSecrets.getSecret();
    } catch (err) {
      throw err;
    } finally {
      await KeyVaultSecrets.deleteSecret();
    }
  }

var http = require('http');
const {DefaultAzureCredential} = require('@azure/identity');
const {SecretClient} = require('@azure/keyvault-secrets');
// DefaultAzureCredential expects the following three environment variables:
// - AZURE_TENANT_ID: The tenant ID in Azure Active Directory
// - AZURE_CLIENT_ID: The application (client) ID registered in the AAD tenant
// - AZURE_CLIENT_SECRET: The client secret for the registered application
const credential = new DefaultAzureCredential();
  
const vaultName = process.env["KEYVAULT_NAME"] || "";
const url = `https://${vaultName}.vault.azure.net`;
  
const client = new SecretClient(url, credential);

const secretName = "MySecretName";

var server = http.createServer(function(request, response) {
    response.writeHead(200, {"Content-Type": "text/plain"});
});

async function main(){
    // Create a secret
    const result = await client.setSecret(secretName, "MySecretValue");
    console.log("Secret name: ", result.name);
    // Read the secret we created
    const secret = await client.getSecret(secretName);
    console.log("Successfully retrieved 'MySecretName':", secret.value);
}

export async function login(): Promise {
  const creds = await msRestNodeAuth.loginWithServicePrincipalSecret(clientId, secret, tenant)
  const websites = new appservice.WebSiteManagementClient(creds as any, subscriptionId)
  return {
    websites,
    webapps: new appservice.WebApps(websites),
    secrets: new SecretClient(`https://majavashakki-vault.vault.azure.net`, new EnvironmentCredential()),
    cosmosdb: new cosmosdb.CosmosDBManagementClient(creds as any, subscriptionId),
    containerregistry: new ContainerRegistryManagementClient(creds as any, subscriptionId),
  }
}