Function download_cli

python/copilot/_cli_download.py:207–304

Download the Copilot CLI binary and cache it. Args: version: CLI version to download. Defaults to the pinned CLI_VERSION. force: If True, re-download even if already cached. Returns: Path to the cached binary. Raises: RuntimeError: If the version is not

(version: str | None = None, *, force: bool = False)

def download_cli(version: str | None = None, *, force: bool = False) -> str:
    """Download the Copilot CLI binary and cache it.

    Args:
        version: CLI version to download. Defaults to the pinned CLI_VERSION.
        force: If True, re-download even if already cached.

    Returns:
        Path to the cached binary.

    Raises:
        RuntimeError: If the version is not set, download fails, or
                      checksum verification fails.
    """
    ver = version or CLI_VERSION
    if not ver:
        raise RuntimeError(
            "No CLI version pinned. This is a development install — "
            "set COPILOT_CLI_PATH or install a published wheel."
        )

    archive_name, binary_name = get_asset_info()
    cache_dir = get_cache_dir(ver)
    binary_path = cache_dir / binary_name

    # Return cached binary if available (unless force)
    if not force and binary_path.exists():
        return str(binary_path)

    # Fetch checksums
    checksums = _fetch_checksums(ver)
    expected_hash = checksums.get(archive_name)
    if not expected_hash:
        raise RuntimeError(
            f"No checksum found for '{archive_name}' in SHA256SUMS.txt. "
            f"Available files: {list(checksums.keys())}"
        )

    # Download archive with retries
    url = get_download_url(ver, archive_name)
    last_exc: Exception | None = None
    data: bytes | None = None
    for attempt in range(_MAX_RETRIES):
        try:
            with urlopen(url, timeout=120) as response:
                data = response.read()
            break
        except (HTTPError, URLError) as exc:
            last_exc = exc
            if attempt < _MAX_RETRIES - 1:
                time.sleep(2**attempt)
    if data is None:
        raise RuntimeError(
            f"Failed to download runtime from {url}: {last_exc}\n\n"
            "If you are in an offline or firewalled environment, you can:\n"
            f"1. Manually download the archive from: {url}\n"
            f"2. Extract the '{binary_name}' binary to: {binary_path}\n"
            "Or set COPILOT_CLI_PATH to point to an existing binary."