Add sandbox configuration to enable Docker for language support testing

[Copilot]

The language support tester workflow failed because containerized MCP servers (Serena) require Docker access, which standard GitHub Actions runners don't provide.

Changes

• Added sandbox.mcp.container configuration pointing to ghcr.io/github/gh-aw-mcpg

sandbox:
  mcp:
    container: "ghcr.io/github/gh-aw-mcpg"

This provides Docker-in-Docker support via the MCP Gateway container, matching the pattern used in large-payload-tester and nightly-mcp-stress-test workflows.

Impact

Unblocks testing for:

• Go language support (main repository)
• TypeScript/JavaScript support (test/serena-mcp-tests/samples/js_project/)
• Python support (test/serena-mcp-tests/samples/python_project/)

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:

• https://api.github.com/graphql
  • Triggering command: /usr/bin/gh /usr/bin/gh api graphql -f query=query($owner: String!, $name: String!) { repository(owner: $owner, name: $name) { hasDiscussionsEnabled } } -f owner=github -f name=gh-aw-mcpg (http block)
• https://api.github.com/repos/actions/download-artifact/git/ref/tags/v6
  • Triggering command: /usr/bin/gh gh api /repos/actions/download-artifact/git/ref/tags/v6 --jq .object.sha (http block)
• https://api.github.com/repos/actions/setup-go/git/ref/tags/4dc6199c7b1a012772edbd06daecab0f50c9053c
  • Triggering command: /usr/bin/gh gh api /repos/actions/setup-go/git/ref/tags/4dc6199c7b1a012772edbd06daecab0f50c9053c --jq .object.sha (http block)
• https://api.github.com/repos/actions/upload-artifact/git/ref/tags/v6
  • Triggering command: /usr/bin/gh gh api /repos/actions/upload-artifact/git/ref/tags/v6 --jq .object.sha (http block)
• https://api.github.com/repos/github/gh-aw/git/ref/tags/v0.45.4
  • Triggering command: /usr/bin/gh gh api /repos/github/gh-aw/git/ref/tags/v0.45.4 --jq .object.sha (http block)
• https://api.github.com/user
  • Triggering command: /usr/bin/gh gh api user --jq .login (http 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

---

This section details on the original issue you should resolve

<issue_title>[language-support] Language support testing blocked by infrastructure issues</issue_title>
<issue_description>## Summary

Language support testing for Go, TypeScript/JavaScript, and Python via the Serena MCP server is currently blocked due to infrastructure limitations in the workflow environment.

Problems Identified

1. Go Version Mismatch

• Required: Go 1.25.0 (per go.mod)
• Available: Go 1.24.13
• Impact: Cannot build the MCP Gateway binary
• Error: go: go.mod requires go >= 1.25.0 (running go 1.24.13; GOTOOLCHAIN=local)

Attempted workaround: Using GOTOOLCHAIN=auto fails with network error:

go: downloading go1.25.0 (linux/amd64)
go: download go1.25.0: golang.org/toolchain@v0.0.1-go1.25.0.linux-amd64: 
Get "(proxy.golang.org/redacted) Forbidden

2. Docker Daemon Unavailable

• Issue: Cannot connect to Docker daemon at unix:///var/run/docker.sock
• Impact: Cannot run containerized MCP servers (including Serena)
• Error: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

3. All Language Tests Blocked

❌ Go Language Support

• Cannot activate Go project via Serena
• Cannot test Go symbol finding or language server functionality

❌ TypeScript/JavaScript Language Support

• Cannot activate TypeScript project at test/serena-mcp-tests/samples/js_project/
• Cannot test TypeScript/JavaScript symbol finding

❌ Python Language Support

• Cannot activate Python project at test/serena-mcp-tests/samples/python_project/
• Cannot test Python symbol finding (e.g., Calculator class)

Configuration Status

✅ Working:

• Config file exists (config.toml)
• Serena MCP server is properly configured
• Test sample projects exist for JS and Python

❌ Broken:

• Go toolchain version
• Docker daemon access
• Network access to Go proxy for toolchain downloads

Recommended Solutions

1. Update workflow setup: Install Go 1.25.0 in the workflow environment

   - uses: actions/setup-go@v6
     with:
       go-version: '1.25.0'

2. Enable Docker: Ensure Docker daemon is available in the workflow

   • Use runs-on with Docker support
   • Or use GitHub's container services

3. Allow network access: If using GOTOOLCHAIN=auto, ensure proxy.golang.org is accessible

Workflow Context

• Workflow: language-support-tester
• Run ID: 22100526047
• Repository: github/gh-aw-mcpg
• Workspace: /home/runner/work/gh-aw-mcpg/gh-aw-mcpg

Next Steps

Once infrastructure issues are resolved, re-run the workflow to test:

1. Go language support (main repository code)
2. TypeScript/JavaScript support (test samples)
3. Python support (test samples)

The workflow will verify that each language's tooling (activation, symbol finding, language server) works correctly via the Serena MCP server.

Generated by Language Support Tester

• expires on Feb 24, 2026, 1:44 PM UTC

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

• Fixes [language-support] Language support testing blocked by infrastructure issues #1035

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[Copilot]

Pull request overview

Adds an explicit sandbox MCP container configuration to the Language Support Tester agentic workflow so containerized MCP servers (e.g., Serena) can access Docker via the MCP Gateway container, aligning this workflow with other Docker-enabled workflows in the repo.

Changes:

• Add sandbox.mcp.container: "ghcr.io/github/gh-aw-mcpg" to .github/workflows/language-support-tester.md.
• Update the generated frontmatter-hash in .github/workflows/language-support-tester.lock.yml to reflect the frontmatter change.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
.github/workflows/language-support-tester.md	Adds sandbox configuration to enable Docker-in-Docker support for containerized MCP servers during language support testing.
.github/workflows/language-support-tester.lock.yml	Updates frontmatter hash to stay in sync with the workflow definition change.

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