Add support for proxy

[DevAcc24]

Is your feature request related to a problem? Please describe.
It is impossible to use SWA-CLI to deploy application when organization forces to use proxy.
Part of the problem related to node-fetch used (for example) to load StaticSitesClient. This could be solved by using http-proxy-agent & https-proxy-agent (see sample fetch-proxy.ts below). In this case SWA-CLI could be used when --deployment-token explicitly specified on command line so there is no need to fetch is from SWA itself.
Another part of the same problem with @azure/arm-appservice dependency of @azure/static-web-apps-cli making it impossible to fetch information about existing applications from Azure.

Describe the solution you'd like
It would be great if SWA-CLI use HTTP_PROXY & HTTPS_PROXY environment variables when communicating with Azure services.

Describe alternatives you've considered
Add additional optional command line parameters like --http-proxy and --https-proxy so could explicitly specify proxy to be used for communication.

Additional context
Below command output on Win11.
Deploy command without --deployment-token parameter.

C:\Dev\myapp>npx swa deploy --verbose=silly

Welcome to Azure Static Web Apps CLI (2.0.3)

Getting config file options from "swa-cli.config.json"...
Config file does not exist at "swa-cli.config.json"
Resolving outputLocation=. full path...
Deploying front-end files from folder:
  C:\Dev\myapp\dist

(node:1884) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
Consider providing api-language and version using --api-language and --api-version flags,
    otherwise default values apiLanguage: node and apiVersion: 16 will apply
No deployment token found. Trying interactive login...
Checking Azure session...
Executing authenticateWithAzureIdentity
- details:
  - tenantId: <undefined>
  - clientId: <undefined>
  - clientSecret: <undefined>
 - useKeychain: true
Keychain is enabled
Executing swaCliPersistencePlugin
✔ Successfully logged into Azure!
Found an existing Azure config file, getting Tenant and Subscription Id from C:\Users\User\.azure\azureProfile.json
Selected tenant: <REDACTED>
Selected subscription: <REDACTED>
Project credentials:
 - subscriptionId: <REDACTED>
 - tenantId: <REDACTED>
 - clientId: <undefined>
 - clientSecret: <undefined>
✔ Saved project credentials in .env file.
No .gitignore file found. Skip updating .gitignore
Login successful

Checking project settings...
✖

C:\Dev\myapp>

Deploy command with --deployment-token parameter.

C:\Dev\myapp>npx swa deploy --resource-group RESGROUPNAME --app-name APPNAME --env production --deployment-token <REDACTED> --verbose=silly

Welcome to Azure Static Web Apps CLI (2.0.2)

Getting config file options from "swa-cli.config.json"...
(node:23676) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
Changed directory to C:\Dev\myapp
Using configuration "myapp" from file:
  C:\Dev\myapp\swa-cli.config.json

Resolving outputLocation=dist\myapp full path...
Deploying front-end files from folder:
  C:\Dev\myapp\dist\myapp

Consider providing api-language and version using --api-language and --api-version flags,
    otherwise default values apiLanguage: node and apiVersion: 16 will apply
Deployment token provided via flag
 - --deployment-token: <hidden>

Deploying to environment: production

Trying to read workflow config with values:
 - appLocation: C:\Dev\myapp
 - outputLocation: C:\Dev\myapp\dist\myapp
 - apiLocation: <undefined>
 - dataApiLocation: <undefined>
No workflow config folder found at C:\Dev\myapp\.github\workflows
Validating user workflow config (BEFORE):
 - appLocation: C:\Dev\myapp
 - outputLocation: C:\Dev\myapp\dist\myapp
 - apiLocation: <undefined>
 - dataApiLocation: <undefined>
Validating user workflow config (AFTER):
 - appLocation: C:\Dev\myapp
 - apiLocation: <undefined>
 - outputLocation: C:\Dev\myapp\dist\myapp
 - dataApiLocation: <undefined>
Reading content from staticwebapp.config.json...
Parsing C:\Dev\myapp\staticwebapp.config.json...
Content parsed successfully

Found configuration file:
  C:\Dev\myapp\staticwebapp.config.json

Deploying project to Azure Static Web Apps...
Fetching release metadata for version: stable. Please wait...
GET https://aka.ms/swalocaldeploy
Could not find release metadata; returning undefined
✖
✖ Deployment Failed :(
✖ Deployment Failure Reason: Could not load StaticSitesClient metadata from remote. Please check your internet connection.
✖ For further information, please visit the Azure Static Web Apps documentation at https://docs.microsoft.com/azure/static-web-apps/

✖ If you believe this behavior is unexpected, please raise a GitHub issue at:
  https://github.com/Azure/static-web-apps-cli/issues/new/choose

C:\Dev\myapp>

Sample implementation of proxy support for node-fetch:

import { HttpProxyAgent } from "http-proxy-agent";
import { HttpsProxyAgent } from "https-proxy-agent";
import fetch from "node-fetch";
import { logger } from "./logger.js";

function getProxyUrl(envVar: string): string {
  const lowerCaseUrl = envVar.toLowerCase(); // Normalize case for checking
  const result = lowerCaseUrl.startsWith("http://") || lowerCaseUrl.startsWith("https://")
    ? envVar
    : `http://${envVar}`;
  logger.silly(`Using proxy: ${result}`);
  return result;
}

export function getGetProxyAgent(): HttpProxyAgent<string> | HttpsProxyAgent<string> | undefined {
  return process.env.HTTPS_PROXY
    ? new HttpsProxyAgent(getProxyUrl(process.env.HTTPS_PROXY))
    : process.env.HTTP_PROXY
        ? new HttpProxyAgent(getProxyUrl(process.env.HTTP_PROXY))
        : undefined;
}

export function fetchWithProxy(input: fetch.RequestInfo, init?: fetch.RequestInit): Promise<fetch.Response> {
  const useAgent = getGetProxyAgent();
  if (useAgent !== undefined) {
    return fetch(input, { ...init, agent: useAgent });
  } else {
    return fetch(input, init);
  }
}

Then replace

import fetch from "node-fetch";

with

import { fetchWithProxy as fetch } from "./utils/fetch-proxy.js";

[Timothyw0]

Hi @DevAcc24 could you please try again with the latest v2.0.4 release? The fix has been released

[DevAcc24]

@Timothyw0, with 2.0.4 seems to work as expected. Thanks!