静的ファイル - StaticFiles

JavaScript、CSS、画像などの静的ファイルを配信するには、StaticFiles クラスを使用できます。

FastAPI の静的ファイルに関するドキュメントで詳細をご覧ください。

fastapi.staticfiles から直接インポートできます

from fastapi.staticfiles import StaticFiles

fastapi.staticfiles.StaticFiles

StaticFiles(
    *,
    directory=None,
    packages=None,
    html=False,
    check_dir=True,
    follow_symlink=False
)

starlette/staticfiles.py のソースコード

def __init__(
    self,
    *,
    directory: PathLike | None = None,
    packages: list[str | tuple[str, str]] | None = None,
    html: bool = False,
    check_dir: bool = True,
    follow_symlink: bool = False,
) -> None:
    self.directory = directory
    self.packages = packages
    self.all_directories = self.get_directories(directory, packages)
    self.html = html
    self.config_checked = False
    self.follow_symlink = follow_symlink
    if check_dir and directory is not None and not os.path.isdir(directory):
        raise RuntimeError(f"Directory '{directory}' does not exist")

directory instance-attribute

directory = directory

packages instance-attribute

packages = packages

all_directories instance-attribute

all_directories = get_directories(directory, packages)

html instance-attribute

html = html

config_checked instance-attribute

config_checked = False

follow_symlink instance-attribute

follow_symlink = follow_symlink

get_directories

get_directories(directory=None, packages=None)

directory および packages 引数に基づいて、静的ファイルの提供に使用されるすべてのディレクトリのリストを返します。

starlette/staticfiles.py のソースコード

def get_directories(
    self,
    directory: PathLike | None = None,
    packages: list[str | tuple[str, str]] | None = None,
) -> list[PathLike]:
    """
    Given `directory` and `packages` arguments, return a list of all the
    directories that should be used for serving static files from.
    """
    directories = []
    if directory is not None:
        directories.append(directory)

    for package in packages or []:
        if isinstance(package, tuple):
            package, statics_dir = package
        else:
            statics_dir = "statics"
        spec = importlib.util.find_spec(package)
        assert spec is not None, f"Package {package!r} could not be found."
        assert spec.origin is not None, f"Package {package!r} could not be found."
        package_directory = os.path.normpath(os.path.join(spec.origin, "..", statics_dir))
        assert os.path.isdir(package_directory), (
            f"Directory '{statics_dir!r}' in package {package!r} could not be found."
        )
        directories.append(package_directory)

    return directories

get_path

get_path(scope)

ASGI スコープに基づいて、OS 固有のパス区切り文字で、'..', '.' コンポーネントが削除された、提供する path 文字列を返します。

starlette/staticfiles.py のソースコード

def get_path(self, scope: Scope) -> str:
    """
    Given the ASGI scope, return the `path` string to serve up,
    with OS specific path separators, and any '..', '.' components removed.
    """
    route_path = get_route_path(scope)
    return os.path.normpath(os.path.join(*route_path.split("/")))

get_response async

get_response(path, scope)

受信したパス、メソッド、およびリクエストヘッダーに基づいて HTTP レスポンスを返します。

starlette/staticfiles.py のソースコード

async def get_response(self, path: str, scope: Scope) -> Response:
    """
    Returns an HTTP response, given the incoming path, method and request headers.
    """
    if scope["method"] not in ("GET", "HEAD"):
        raise HTTPException(status_code=405)

    try:
        full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, path)
    except PermissionError:
        raise HTTPException(status_code=401)
    except OSError as exc:
        # Filename is too long, so it can't be a valid static file.
        if exc.errno == errno.ENAMETOOLONG:
            raise HTTPException(status_code=404)

        raise exc

    if stat_result and stat.S_ISREG(stat_result.st_mode):
        # We have a static file to serve.
        return self.file_response(full_path, stat_result, scope)

    elif stat_result and stat.S_ISDIR(stat_result.st_mode) and self.html:
        # We're in HTML mode, and have got a directory URL.
        # Check if we have 'index.html' file to serve.
        index_path = os.path.join(path, "index.html")
        full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, index_path)
        if stat_result is not None and stat.S_ISREG(stat_result.st_mode):
            if not scope["path"].endswith("/"):
                # Directory URLs should redirect to always end in "/".
                url = URL(scope=scope)
                url = url.replace(path=url.path + "/")
                return RedirectResponse(url=url)
            return self.file_response(full_path, stat_result, scope)

    if self.html:
        # Check for '404.html' if we're in HTML mode.
        full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, "404.html")
        if stat_result and stat.S_ISREG(stat_result.st_mode):
            return FileResponse(full_path, stat_result=stat_result, status_code=404)
    raise HTTPException(status_code=404)

lookup_path

lookup_path(path)

starlette/staticfiles.py のソースコード

def lookup_path(self, path: str) -> tuple[str, os.stat_result | None]:
    for directory in self.all_directories:
        joined_path = os.path.join(directory, path)
        if self.follow_symlink:
            full_path = os.path.abspath(joined_path)
            directory = os.path.abspath(directory)
        else:
            full_path = os.path.realpath(joined_path)
            directory = os.path.realpath(directory)
        if os.path.commonpath([full_path, directory]) != str(directory):
            # Don't allow misbehaving clients to break out of the static files directory.
            continue
        try:
            return full_path, os.stat(full_path)
        except (FileNotFoundError, NotADirectoryError):
            continue
    return "", None

file_response

file_response(
    full_path, stat_result, scope, status_code=200
)

starlette/staticfiles.py のソースコード

def file_response(
    self,
    full_path: PathLike,
    stat_result: os.stat_result,
    scope: Scope,
    status_code: int = 200,
) -> Response:
    request_headers = Headers(scope=scope)

    response = FileResponse(full_path, status_code=status_code, stat_result=stat_result)
    if self.is_not_modified(response.headers, request_headers):
        return NotModifiedResponse(response.headers)
    return response

check_config async

check_config()

StaticFiles が実際にディレクトリを指していることを一度だけ確認する構成チェックを実行します。これにより、404 レスポンスを返すだけでなく、大きなエラーを発生させることができます。

starlette/staticfiles.py のソースコード

async def check_config(self) -> None:
    """
    Perform a one-off configuration check that StaticFiles is actually
    pointed at a directory, so that we can raise loud errors rather than
    just returning 404 responses.
    """
    if self.directory is None:
        return

    try:
        stat_result = await anyio.to_thread.run_sync(os.stat, self.directory)
    except FileNotFoundError:
        raise RuntimeError(f"StaticFiles directory '{self.directory}' does not exist.")
    if not (stat.S_ISDIR(stat_result.st_mode) or stat.S_ISLNK(stat_result.st_mode)):
        raise RuntimeError(f"StaticFiles path '{self.directory}' is not a directory.")

is_not_modified

is_not_modified(response_headers, request_headers)

リクエストとレスポンスのヘッダーに基づいて、HTTP の「未変更」レスポンスを代わりに返すことができる場合は True を返します。

starlette/staticfiles.py のソースコード

def is_not_modified(self, response_headers: Headers, request_headers: Headers) -> bool:
    """
    Given the request and response headers, return `True` if an HTTP
    "Not Modified" response could be returned instead.
    """
    try:
        if_none_match = request_headers["if-none-match"]
        etag = response_headers["etag"]
        if etag in [tag.strip(" W/") for tag in if_none_match.split(",")]:
            return True
    except KeyError:
        pass

    try:
        if_modified_since = parsedate(request_headers["if-modified-since"])
        last_modified = parsedate(response_headers["last-modified"])
        if if_modified_since is not None and last_modified is not None and if_modified_since >= last_modified:
            return True
    except KeyError:
        pass

    return False