Add NO_PROXY support for corporate firewall environments

[Copilot]

HTTP_PROXY/HTTPS_PROXY were supported but NO_PROXY was not, preventing bypass of proxy for self-hosted GitLab instances.

Changes

Core Implementation

• Added shouldBypassProxy() in gitlab-client-pool.ts with standard pattern matching:
  • Exact hostname/IP (localhost, 192.168.1.1)
  • Domain suffix (.internal.com)
  • Port-specific (example.com:443)
  • Wildcard (*)
  • Case-insensitive
• Modified createAgentsForUrl() to skip proxy agent creation when host matches NO_PROXY patterns
• Added noProxy parameter to GitLabClientPoolOptions interface

Configuration

• Environment variable: NO_PROXY
• CLI argument: --no-proxy
• Passed through getConfig() in index.ts to GitLabClientPool constructor

Usage

{
  "env": {
    "HTTP_PROXY": "http://proxy.corp.com:8080",
    "HTTPS_PROXY": "http://proxy.corp.com:8080",
    "NO_PROXY": "localhost,127.0.0.1,.internal.com,gitlab.mycompany.com"
  }
}

Requests to gitlab.mycompany.com bypass proxy while external requests use it.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• nonexistent-proxy.example.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/gitlab-mcp/gitlab-mcp/build/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Support NO_PROXY settings</issue_title>
<issue_description>This would allow support for those behind corporate firewalls with self-hosted gitlab instances. While there is logic for HTTP_PROXY/HTTPS_PROXY there does not see to be logic for setting NO_PROXY. </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Support NO_PROXY settings #348

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