# `http.server` --- HTTP サーバー

ソースコード: Lib/http/server.py

このモジュールは HTTP サーバを実装するためのクラスを提供しています。

警告

`http.server` is not recommended for production. It only implements basic security checks.

Availability: not WASI.

このモジュールは WebAssembly では動作しないか、利用不可です。詳しくは、WebAssembly プラットフォーム を見てください。

クラス `HTTPServer` は `socketserver.TCPServer` のサブクラスです。 `HTTPServer` は HTTP ソケットを生成してリクエスト待ち (listen) を行い、リクエストをハンドラに渡します。 サーバを作成して動作させるためのコードは以下のようになります:

    def run(server_class=HTTPServer, handler_class=BaseHTTPRequestHandler):
        server_address = ('', 8000)
        httpd = server_class(server_address, handler_class)
        httpd.serve_forever()

class http.server.HTTPServer(server_address, RequestHandlerClass)

  This class builds on the `TCPServer` class by storing the server address as instance variables named `server_name` and `server_port`. The server is accessible by the handler, typically through the handler's `server` instance variable.

  server_name

    The HTTP server's fully qualified domain name.

  server_port

    The HTTP server's port number obtained from server_address.

class http.server.ThreadingHTTPServer(server_address, RequestHandlerClass)

  This class is identical to HTTPServer but uses threads to handle requests by using the `ThreadingMixIn`. This is useful to handle web browsers pre-opening sockets, on which `HTTPServer` would wait indefinitely.

  Added in version 3.7.

class http.server.HTTPSServer(server_address, RequestHandlerClass, bind_and_activate=True, *, certfile, keyfile=None, password=None, alpn_protocols=None)

  Subclass of `HTTPServer` with a wrapped socket using the `ssl` module. If the `ssl` module is not available, instantiating a `HTTPSServer` object fails with a `RuntimeError`.

  The certfile argument is the path to the SSL certificate chain file, and the keyfile is the path to the file containing the private key.

  A password can be specified for files protected and wrapped with PKCS#8, but beware that this could possibly expose hardcoded passwords in clear.

  参考

  See `ssl.SSLContext.load_cert_chain()` for additional information on the accepted values for certfile, keyfile and password.

  When specified, the alpn_protocols argument must be a sequence of strings specifying the "Application-Layer Protocol Negotiation" (ALPN) protocols supported by the server. ALPN allows the server and the client to negotiate the application protocol during the TLS handshake.

  By default, it is set to `["http/1.1"]`, meaning the server supports HTTP/1.1.

  Added in version 3.14.

class http.server.ThreadingHTTPSServer(server_address, RequestHandlerClass, bind_and_activate=True, *, certfile, keyfile=None, password=None, alpn_protocols=None)

  This class is identical to `HTTPSServer` but uses threads to handle requests by inheriting from `ThreadingMixIn`. This is analogous to `ThreadingHTTPServer` only using `HTTPSServer`.

  Added in version 3.14.

The `HTTPServer`, `ThreadingHTTPServer`, `HTTPSServer` and `ThreadingHTTPSServer` must be given a RequestHandlerClass on instantiation, of which this module provides three different variants:

class http.server.BaseHTTPRequestHandler(request, client_address, server)

  This class is used to handle the HTTP requests that arrive at the server. By itself, it cannot respond to any actual HTTP requests; it must be subclassed to handle each request method (for example, `'GET'` or `'POST'`). `BaseHTTPRequestHandler` provides a number of class and instance variables, and methods for use by subclasses.

  The handler will parse the request and the headers, then call a method specific to the request type. The method name is constructed from the request. For example, for the request method `SPAM`, the `do_SPAM()` method will be called with no arguments. All of the relevant information is stored in instance variables of the handler. Subclasses should not need to override or extend the `__init__()` method.

  `BaseHTTPRequestHandler` は以下のインスタンス変数を持っています:

  client_address

    HTTP クライアントのアドレスを参照している、`(host, port)` の形式をとるタプルが入っています。

  server

    server インスタンスが入っています。

  close_connection

    `handle_one_request()` が返る前に設定すべき真偽値で、別のリクエストが期待されているかどうか、もしくはコネクションを切断すべきかどうかを指し示しています。

  requestline

    HTTP リクエスト行の文字列表現を保持しています。 末尾の CRLF は除去されています。 この属性は `handle_one_request()` によって設定されるべきです。 妥当なリクエスト行が1行も処理されなかった場合は、空文字列に設定されるべきです。

  command

    HTTP 命令 (リクエスト形式) が入っています。例えば `'GET'` です。

  path

    Contains the request path. If the query component of the URL is present, then `path` includes the query. Using the terminology of RFC 3986, `path` here includes `hier-part` and the `query`.

  request_version

    リクエストのバージョン文字列が入っています。例えば `'HTTP/1.0'` です。

  headers

    Holds an instance of the class specified by the `MessageClass` class variable. This instance parses and manages the headers in the HTTP request. The `parse_headers()` function from `http.client` is used to parse the headers and it requires that the HTTP request provide a valid RFC 5322 style header.

  rfile

    An `io.BufferedIOBase` input stream, ready to read from the start of the optional input data.

  wfile

    Contains the output stream for writing a response back to the client. Proper adherence to the HTTP protocol must be used when writing to this stream in order to achieve successful interoperation with HTTP clients.

    バージョン 3.6 で変更: This is an `io.BufferedIOBase` stream.

  `BaseHTTPRequestHandler` は以下の属性を持っています:

  server_version

    サーバのソフトウェアバージョンを指定します。この値は上書きする必要が生じるかもしれません。書式は複数の文字列を空白で分割したもので、各文字列はソフトウェア名[/バージョン] の形式をとります。例えば、`'BaseHTTP/0.2'` です。

  sys_version

    Python 処理系のバージョンが, `version_string` メソッドや `server_version` クラス変数で利用可能な形式で入っています。例えば `'Python/1.4'` です。

  error_message_format

    Specifies a format string that should be used by `send_error()` method for building an error response to the client. The string is filled by default with variables from `responses` based on the status code passed to `send_error()`.

  error_content_type

    エラーレスポンスをクライアントに送信する時に使う Content-Type HTTP ヘッダを指定します。デフォルトでは `'text/html'` です。

  protocol_version

    Specifies the HTTP version to which the server is conformant. It is sent in responses to let the client know the server's communication capabilities for future requests. If set to `'HTTP/1.1'`, the server will permit HTTP persistent connections; however, your server must then include an accurate `Content-Length` header (using `send_header()`) in all of its responses to clients. For backwards compatibility, the setting defaults to `'HTTP/1.0'`.

  MessageClass

    HTTP ヘッダを解釈するための `email.message.Message` 類似のクラスを指定します。 通常この値が上書きされることはなく、デフォルトの `http.client.HTTPMessage` になっています。

  responses

    This attribute contains a mapping of error code integers to two-element tuples containing a short and long message. For example, `{code: (shortmessage, longmessage)}`. The shortmessage is usually used as the message key in an error response, and longmessage as the explain key. It is used by `send_response_only()` and `send_error()` methods.

  `BaseHTTPRequestHandler` インスタンスは以下のメソッドを持っています:

  handle()

    Calls `handle_one_request()` once (or, if persistent connections are enabled, multiple times) to handle incoming HTTP requests. You should never need to override it; instead, implement appropriate `do_*()` methods.

  handle_one_request()

    This method will parse and dispatch the request to the appropriate `do_*()` method. You should never need to override it.

  handle_expect_100()

    When an HTTP/1.1 conformant server receives an `Expect: 100-continue` request header it responds with a `100 Continue` followed by `200 OK` headers. This method can be overridden to raise an error if the server does not want the client to continue. For example, the server can choose to send `417 Expectation Failed` as a response header and `return False`.

    Added in version 3.2.

  send_error(code, message=None, explain=None)

    Sends and logs a complete error reply to the client. The numeric code specifies the HTTP error code, with message as an optional, short, human readable description of the error. The explain argument can be used to provide more detailed information about the error; it will be formatted using the `error_message_format` attribute and emitted, after a complete set of headers, as the response body. The `responses` attribute holds the default values for message and explain that will be used if no value is provided; for unknown codes the default value for both is the string `???`. The body will be empty if the method is HEAD or the response code is one of the following: `1xx`, `204 No Content`, `205 Reset Content`, `304 Not Modified`.

    バージョン 3.4 で変更: The error response includes a Content-Length header. Added the explain argument.

  send_response(code, message=None)

    Adds a response header to the headers buffer and logs the accepted request. The HTTP response line is written to the internal buffer, followed by Server and Date headers. The values for these two headers are picked up from the `version_string()` and `date_time_string()` methods, respectively. If the server does not intend to send any other headers using the `send_header()` method, then `send_response()` should be followed by an `end_headers()` call.

    バージョン 3.3 で変更: Headers are stored to an internal buffer and `end_headers()` needs to be called explicitly.

  send_header(keyword, value)

    Adds the HTTP header to an internal buffer which will be written to the output stream when either `end_headers()` or `flush_headers()` is invoked. keyword should specify the header keyword, with value specifying its value. Note that, after the send_header calls are done, `end_headers()` MUST BE called in order to complete the operation.

    This method does not reject input containing CRLF sequences.

    バージョン 3.2 で変更: ヘッダは内部バッファに保存されます。

  send_response_only(code, message=None)

    Sends the response header only, used for the purposes when `100 Continue` response is sent by the server to the client. The headers are not buffered and sent directly the output stream. If the message is not specified, the HTTP message corresponding the response code is sent.

    This method does not reject message containing CRLF sequences.

    Added in version 3.2.

  end_headers()

    Adds a blank line (indicating the end of the HTTP headers in the response) to the headers buffer and calls `flush_headers()`.

    バージョン 3.2 で変更: バッファされたヘッダは出力ストリームに書き出されます。

  flush_headers()

    最終的にヘッダを出力ストリームに送り、内部ヘッダバッファをフラッシュします。

    Added in version 3.3.

  log_request(code='-', size='-')

    受理された (成功した) リクエストをログに記録します。code にはこの応答に関連付けられた HTTP コード番号を指定します。応答メッセージの大きさを知ることができる場合、size パラメタに渡すとよいでしょう。

  log_error(...)

    リクエストを遂行できなかった際に、エラーをログに記録します。標準では、メッセージを `log_message()` に渡します。従って同じ引数 (format と追加の値) を取ります。

  log_message(format, ...)

    Logs an arbitrary message to `sys.stderr`. This is typically overridden to create custom error logging mechanisms. The format argument is a standard printf-style format string, where the additional arguments to `log_message()` are applied as inputs to the formatting. The client IP address and current date and time are prefixed to every message logged.

  version_string()

    サーバーのソフトウェアのバージョンを示す文字列を返します。 その文字列は、`server_version` と `sys_version` の属性が含まれます。

  date_time_string(timestamp=None)

    メッセージヘッダ向けに書式化された、 timestamp (`None` または `time.time()` のフォーマットである必要があります)で与えられた日時を返します。もし timestamp が省略された場合には、現在の日時が使われます。

    出力は `'Sun, 06 Nov 1994 08:49:37 GMT'` のようになります。

  log_date_time_string()

    ログ記録向けに書式化された、現在の日付および時刻を返します。

  address_string()

    クライアントのアドレスを返します。

    バージョン 3.3 で変更: Previously, a name lookup was performed. To avoid name resolution delays, it now always returns the IP address.

class http.server.SimpleHTTPRequestHandler(request, client_address, server, directory=None)

  This class serves files from the directory directory and below, or the current directory if directory is not provided, directly mapping the directory structure to HTTP requests.

  バージョン 3.7 で変更: Added the directory parameter.

  バージョン 3.9 で変更: The directory parameter accepts a path-like object.

  リクエストの解釈のような、多くの作業は基底クラス `BaseHTTPRequestHandler` で行われます。このクラスは関数 `do_GET()` および `do_HEAD()` を実装しています。

  `SimpleHTTPRequestHandler` では以下のメンバ変数を定義しています:

  server_version

    この値は `"SimpleHTTP/" + __version__` になります。`__version__` はこのモジュールで定義されている値です。

  index_pages

    Specifies the filenames that are treated as directory index pages.

    Defaults to `("index.html", "index.htm")`.

    Added in version 3.12.

  extensions_map

    A dictionary mapping suffixes into MIME types, contains custom overrides for the default system mappings. The mapping is used case-insensitively, and so should contain only lower-cased keys.

    バージョン 3.9 で変更: This dictionary is no longer filled with the default system mappings, but only contains overrides.

  `SimpleHTTPRequestHandler` では以下のメソッドを定義しています:

  do_HEAD()

    このメソッドは `'HEAD'` 型のリクエスト処理を実行します: すなわち、 `GET` リクエストの時に送信されるものと同じヘッダを送信します。送信される可能性のあるヘッダについての完全な説明は `do_GET()` メソッドを参照してください。

  do_GET()

    リクエストを現在の作業ディレクトリからの相対的なパスとして解釈することで、リクエストをローカルシステム上のファイルと対応付けます。

    If the request was mapped to a directory, the directory is checked for an index page as specified by `index_pages`. If found, the file's contents are returned; otherwise a directory listing is generated by calling the `list_directory()` method. This method uses `os.listdir()` to scan the directory, and returns a `404` error response if the `listdir()` fails.

    If the request was mapped to a file, it is opened. Any `OSError` exception in opening the requested file is mapped to a `404`, `'File not found'` error. If there was an `'If-Modified-Since'` header in the request, and the file was not modified after this time, a `304`, `'Not Modified'` response is sent. Otherwise, the content type is guessed by calling the `guess_type()` method, which in turn uses the extensions_map variable, and the file contents are returned.

    出力は `'Content-type:'` と推測されたコンテントタイプで、その後にファイルサイズを示す `'Content-Length;'` ヘッダと、ファイルの更新日時を示す `'Last-Modified:'` ヘッダが続きます。

    Then follows a blank line signifying the end of the headers, and then the contents of the file are output.

    For example usage, see the implementation of the `test` function in Lib/http/server.py.

    バージョン 3.7 で変更: Support of the `'If-Modified-Since'` header.

  list_directory(path)

    Helper to list the contents of path when no index page is present.

    This returns either a file-like object (which must be closed by the caller) or `None` to indicate an error, in which case the caller has nothing further to do. In either case, the headers are sent.

  guess_type(path)

    Guess the type of the file at the given path.

    This returns a string of the form `type/subtype`, usable for a MIME Content-type header.

    The default implementation looks the file's extension up in `extensions_map`, falling back to `mimetypes.guess_file_type()` and then to `'application/octet-stream'`.

    バージョン 3.13 で変更: Add `mimetypes.guess_file_type()` as a fallback.

The `SimpleHTTPRequestHandler` class can be used to create a very basic webserver serving files relative to the current directory as follows:

    import http.server
    import socketserver

    PORT = 8000

    Handler = http.server.SimpleHTTPRequestHandler

    with socketserver.TCPServer(("", PORT), Handler) as httpd:
        print("serving at port", PORT)
        httpd.serve_forever()

`SimpleHTTPRequestHandler` can also be subclassed to enhance behavior, such as using different index file names by overriding the class attribute `index_pages`.

class http.server.CGIHTTPRequestHandler(request, client_address, server)

  This class is used to serve either files or output of CGI scripts from the current directory and below. Note that mapping HTTP hierarchic structure to local directory structure is exactly as in `SimpleHTTPRequestHandler`.

  注釈

  CGI scripts run by the `CGIHTTPRequestHandler` class cannot execute redirects (HTTP code 302), because code 200 (script output follows) is sent prior to execution of the CGI script. This pre-empts the status code.

  The class will however, run the CGI script, instead of serving it as a file, if it guesses it to be a CGI script. Only directory-based CGI are used --- the other common server configuration is to treat special extensions as denoting CGI scripts.

  The `do_GET()` and `do_HEAD()` functions are modified to run CGI scripts and serve the output, instead of serving files, if the request leads to somewhere below the `cgi_directories` path.

  The `CGIHTTPRequestHandler` defines the following data member:

  cgi_directories

    This defaults to `['/cgi-bin', '/htbin']` and describes directories to treat as containing CGI scripts.

  The `CGIHTTPRequestHandler` defines the following method:

  do_POST()

    This method serves the `'POST'` request type, only allowed for CGI scripts. Error 501, "Can only POST to CGI scripts", is output when trying to POST to a non-CGI url.

  Note that CGI scripts will be run with UID of user nobody, for security reasons. Problems with the CGI script will be translated to error 403.

  バージョン 3.13 で非推奨、バージョン 3.15 で削除予定: `CGIHTTPRequestHandler` is being removed in 3.15. CGI has not been considered a good way to do things for well over a decade. This code has been unmaintained for a while now and sees very little practical use. Retaining it could lead to further security considerations.

## コマンドライン・インターフェース

`http.server` can also be invoked directly using the `-m` switch of the interpreter. The following example illustrates how to serve files relative to the current directory:

    python -m http.server [OPTIONS] [port]

以下のオプションが使用できます:

port

  The server listens to port 8000 by default. The default can be overridden by passing the desired port number as an argument:

      python -m http.server 9000

-b, --bind <address>

  Specifies a specific address to which it should bind. Both IPv4 and IPv6 addresses are supported. By default, the server binds itself to all interfaces. For example, the following command causes the server to bind to localhost only:

      python -m http.server --bind 127.0.0.1

  Added in version 3.4.

  バージョン 3.8 で変更: Support IPv6 in the `--bind` option.

-d, --directory <dir>

  Specifies a directory to which it should serve the files. By default, the server uses the current directory. For example, the following command uses a specific directory:

      python -m http.server --directory /tmp/

  Added in version 3.7.

-p, --protocol <version>

  Specifies the HTTP version to which the server is conformant. By default, the server is conformant to HTTP/1.0. For example, the following command runs an HTTP/1.1 conformant server:

      python -m http.server --protocol HTTP/1.1

  Added in version 3.11.

--cgi

  `CGIHTTPRequestHandler` can be enabled in the command line by passing the `--cgi` option:

      python -m http.server --cgi

  バージョン 3.13 で非推奨、バージョン 3.15 で削除予定: `http.server` command line `--cgi` support is being removed because `CGIHTTPRequestHandler` is being removed.

警告

`CGIHTTPRequestHandler` and the `--cgi` command-line option are not intended for use by untrusted clients and may be vulnerable to exploitation. Always use within a secure environment.

--tls-cert

  Specifies a TLS certificate chain for HTTPS connections:

      python -m http.server --tls-cert fullchain.pem

  Added in version 3.14.

--tls-key

  Specifies a private key file for HTTPS connections.

  This option requires `--tls-cert` to be specified.

  Added in version 3.14.

--tls-password-file

  Specifies the password file for password-protected private keys:

      python -m http.server \
             --tls-cert cert.pem \
             --tls-key key.pem \
             --tls-password-file password.txt

  This option requires `--tls-cert` to be specified.

  Added in version 3.14.

## セキュリティで考慮すべき点

`SimpleHTTPRequestHandler` will follow symbolic links when handling requests which makes it possible for files outside of the specified directory to be served.

Methods `BaseHTTPRequestHandler.send_header()` and `BaseHTTPRequestHandler.send_response_only()` assume sanitized input and do not perform input validation such as checking for the presence of CRLF sequences. Untrusted input may result in HTTP header injection attacks.

Earlier versions of Python did not scrub control characters from the log messages emitted to stderr from `python -m http.server` or the default `BaseHTTPRequestHandler` `.log_message` implementation. This could allow remote clients connecting to your server to send nefarious control codes to your terminal.

バージョン 3.12 で変更: Control characters are scrubbed in stderr logs.