🛠 Private Infra Ready: Copilot Coding Agent + Your Self-Hosted Runners (Public Preview)

[ebndev]

Copilot coding agent can now run its development environment on your own infrastructure using self-hosted GitHub Actions runners managed by Actions Runner Controller (ARC). That means agent tasks can reach internal packages, private build tooling, or on-prem services that aren’t exposed to the public internet—while still remaining ephemeral, isolated, and automated.

🤖 What This Unlocks

• Use internal dependency registries or artifact stores (npm, Maven, PyPI mirrors, etc.).
• Run tests against services only reachable inside your network.
• Apply existing compliance / observability layers already baked into your runner fleet.
• Keep Copilot’s environment disposable—every task starts clean, ends clean.

🧩 How It Works (Recap)

Copilot coding agent executes tasks in a GitHub Actions-powered environment. By default we provision hosted runners. Now you can override the environment via copilot-setup-steps.yml and target an ARC scale set.

🔧 Setup Steps

1. Deploy ARC and create a scale set:
   Quickstart: https://docs.github.com/actions/tutorials/use-actions-runner-controller/quickstart
2. Edit copilot-setup-steps.yml in the repository (or org standard) to point to your scale set via runs-on:.
3. Commit & delegate a task to Copilot coding agent—your agent now boots on your infra.

jobs:
  copilot-setup-steps:
    runs-on: arc-scale-set-name
    steps:
      - uses: actions/checkout@v4
      # Add any setup your internal environment needs
      - name: Install private deps
        run: npm ci

🛡️ Security & Isolation Notes

• Each task still uses an ephemeral workspace—no state leakage between tasks.
• Your existing runner-level security policies (network ACLs, scanning, logging) apply automatically.
• Keep secrets management consistent with other ARC-based workflows.

✅ Recommended First Uses

• Internal SDK refactors
• Dependency upgrades needing private registry access
• Integration tests hitting staging APIs behind a firewall
• Legacy monorepo tasks with custom internal toolchains

📎 Tips

• Standardize a base copilot-setup-steps.yml template at the org level for consistency.
• Include lightweight caching if internal dependency retrieval is slow.
• Pair with CodeQL & secret scanning already built into coding agent for layered protection.

📘 Learn More

• Customizing agent environment
• ARC quickstart

💬 Feedback

Let us know what’s missing—metrics visibility? multi-arch scale sets? runner health telemetry surfaced in the agent summary? Drop ideas in comments below:

Bring Copilot to where your code actually lives. 🔐

[GregoireW]

Hello, this day I face an issue when using self hosted runner :

CodeQL asset ID: 304101132
Error ensuring CodeQL: Error: GitHub host is required
Error GitHub host is required 
ERROR: {
  "name": "Error",
  "text": "GitHub host is required",
  "stack": "Error: GitHub host is required\n    at demandGitHubHost (/home/runner/actions-runner/_work/_temp/******-action-main/src/settings/demand.ts:45:15)\n    at async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:45:18)\n    at async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:93:41)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:135:15)\n    at async CodeQLCheckerTool.undefined (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/codeql-checker.ts:61:9)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/config.ts:172:100)\n    at async CreatePRAgent._0x529bf6 (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/agentPrimitives.ts:373:41)\n    at async CreatePRAgent._0x34f311 (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/hostedAgents.ts:35:47)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/index.ts:171:15)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/index.ts:484:13)",
  "message": "GitHub host is required",
  "skipReport": false,
  "isVisionFlow": false
}

Is codeql a prerequisite now ?

Edit: I found 2 ways to fix it:

• Add an GITHUB_HOST env variable that will make the download possible (but 700Mb each time, cost of network / time not great) (warning env on the job is not working, you have to create a step with echo "GITHUB_HOST=github.com" >> $GITHUB_ENV )
• Add codeQL on the host tool (the process is here https://github.com/actions/runner-images/blob/main/images/ubuntu/scripts/build/install-codeql-bundle.sh )

[Carpuncle-Lana]

Hello, this day I face an issue when using self hosted runner 👍

CodeQL asset ID: 304101132
Error ensuring CodeQL: Error: GitHub host is required
Error GitHub host is required 
ERROR: {
  "name": "Error",
  "text": "GitHub host is required",
  "stack": "Error: GitHub host is required\n    at demandGitHubHost (/home/runner/actions-runner/_work/_temp/******-action-main/src/settings/demand.ts:45:15)\n    at async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:45:18)\n    at async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:93:41)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/download-codeql.ts:135:15)\n    at async CodeQLCheckerTool.undefined (/home/runner/actions-runner/_work/_temp/******-action-main/src/tools/codeql/codeql-checker.ts:61:9)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/config.ts:172:100)\n    at async CreatePRAgent._0x529bf6 (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/agentPrimitives.ts:373:41)\n    at async CreatePRAgent._0x34f311 (/home/runner/actions-runner/_work/_temp/******-action-main/src/agents/hostedAgents.ts:35:47)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/index.ts:171:15)\n    at async async (/home/runner/actions-runner/_work/_temp/******-action-main/src/index.ts:484:13)",
  "message": "GitHub host is required",
  "skipReport": false,
  "isVisionFlow": false
}

Is codeql a prerequisite now ?

Edit: I found 2 ways to fix it:

• Add an GITHUB_HOST env variable that will make the download possible (but 700Mb each time, cost of network / time not great) (warning env on the job is not working, you have to create a step with echo "GITHUB_HOST=github.com" >> $GITHUB_ENV )
• Add codeQL on the host tool (the process is here https://github.com/actions/runner-images/blob/main/images/ubuntu/scripts/build/install-codeql-bundle.sh )