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Credential Forwarding

Forward local developer credentials to newly created azlin VMs so tools like gh, az, GitHub Copilot, and Claude Code work immediately — no manual login required.

How It Works

After azlin new creates a VM and SSH becomes reachable, azlin detects which credential sources exist on your local machine and offers to copy them to the VM via SCP.

azlin new --name myproject
  ✓ VM created
  ✓ SSH ready
  Found credentials:
    • GitHub CLI (~/.config/gh)
    • Azure CLI (~/.azure)
    • GitHub Copilot (~/.config/github-copilot)
  Forward GitHub CLI credentials? [y/N] y
    ✓ GitHub CLI credentials forwarded
  Forward Azure CLI credentials? [y/N] y
    ✓ Azure CLI credentials forwarded
  Forward GitHub Copilot credentials? [y/N] n
    ⊘ Skipped

Supported Credentials

Tool Local Source Detection What Gets Copied
GitHub CLI ~/.config/gh/ hosts.yml exists Entire ~/.config/gh/ directory
GitHub Copilot ~/.config/github-copilot/ Directory exists Entire directory
Claude Code ~/.claude.json File exists Single config file
Azure CLI ~/.azure/ Token files exist Allow-listed files only (see Security)

Key Design Principles

Consent-gated: Each credential type prompts for confirmation. Nothing is forwarded silently.

Best-effort: Forwarding failures print a warning but never block VM creation. Your VM is always usable even if credential forwarding fails.

SCP-only: Credentials are copied as files. No tokens are piped through SSH commands or exposed in process arguments.

Detection-first: Only credentials that actually exist locally are offered for forwarding. No prompts for tools you don't use.

Security

Credential forwarding follows a strict security model:

  • Azure CLI allow-list: Only these files are copied from ~/.azure/:

    • azureProfile.json — subscription metadata
    • config — CLI configuration
    • msal_token_cache.json — login tokens
    • msal_token_cache.bin — binary token cache
    • clouds.config — cloud endpoint definitions
    • Service principal credentials (servicePrincipalProfile, accessTokens.json) are never copied.

  • No shell injection: All SSH/SCP commands use Command::new() with argument arrays — never shell interpolation.

  • TOFU SSH: Uses StrictHostKeyChecking=accept-new — accepts the host key on first connect, rejects if it changes later.

  • No password prompts: BatchMode=yes ensures SCP fails cleanly rather than hanging on a password prompt.

  • Non-TTY safety: When running without a terminal (CI/scripts), all confirmations default to "no". Use --yes for scripted forwarding.

Usage

See How to Forward Credentials to a VM for step-by-step instructions.

See Credential Forwarding Reference for CLI flags, environment details, and troubleshooting.