Allow invocation via runpy (python -m goto_http_redirect_server).

[jaraco]

This patch allows the project to be invoked by run_py, such as in this example:

$ pip-run --use-pep517 --quiet git+https://github.com/jaraco/goto_http_redirect_server@feature/runpy-invoke -- -m goto_http_redirect_server --help
usage: goto_http_redirect_server [--redirects REDIRECTS_FILES] [--from-to from to] [--ip IP] [--port PORT]
                                 [--status-path STATUS_PATH] [--reload-path RELOAD_PATH] [--redirect-code REDIRECT_CODE]
                                 [--field-delimiter FIELD_DELIMITER] [--status-note-file STATUS_NOTE_FILE]
                                 [--shutdown SHUTDOWN] [--log LOG] [--debug] [--version] [-?]

The "Go To" HTTP Redirect Server for sharing dynamic shortcut URLs on your network.

HTTP 308 Permanent Redirect reply server. Load this server with redirects of "from path" and
"to URL" and let it run indefinitely. Reload the running server by signaling the
process or HTTP requesting the RELOAD_PATH.

Redirects:
  One or more required. May be passed multiple times.

  --redirects REDIRECTS_FILES
                        File of redirects. Within a file, is one redirect entry per line. A redirect entry is four
                        fields: "from path", "to URL", "added by user", and "added on datetime" separated by the
                        FIELD_DELIMITER character.
  --from-to from to     A single redirect entry of "from path" and "to URL" fields. For example, --from-to "/hr"
                        "http://human-resources.megacorp.local/login"

Network Options:
  --ip IP, -i IP        IP interface to listen on. Default is 0.0.0.0 .
  --port PORT, -p PORT  IP port to listen on. Default is 80 .

Server Options:
  --status-path STATUS_PATH
                        The status path dumps information about the process and loaded redirects. Default status page
                        path is "/status".
  --reload-path RELOAD_PATH
                        Allow reloads by HTTP GET Request to passed URL Path. e.g. --reload-path "/reload". May be a
                        potential security or stability issue. The program will always allow reload by process signal.
                        Default is off.
  --redirect-code REDIRECT_CODE
                        Set HTTP Redirect Status Code as an integer. Most often the desired override will be 307
                        (Temporary Redirect). Any HTTP Status Code could be used but odd things will happen if a value
                        like 500 is returned. This Status Code is only returned when a loaded redirect entry is found and
                        returned. Default successful redirect Status Code is 308 (Permanent Redirect).
  --field-delimiter FIELD_DELIMITER
                        Field delimiter string for --redirects files per-line redirect entries. Default is "\t" (ordinal
                        9).
  --status-note-file STATUS_NOTE_FILE
                        Status page note: Filesystem path to a file with HTML that will be embedded within a <div>
                        element in the status page.
  --shutdown SHUTDOWN   Shutdown the server after passed seconds. Intended for testing.
  --log LOG             Log to file at path LOG. Default logging is to sys.stderr.
  --debug               Set logging level to DEBUG. Default logging level is INFO.
  --version             Print "goto_http_redirect_server 1.1.1" and exit.
  -?, -h, --help        Print this help message and exit.

About Redirect Entries:

  Entries found in --redirects file(s) and entries passed via --from-to are
  combined.
  Entries passed via --from-to override any matching "from path" entry found in
  redirects files.
  The "from path" field corresponds to the URI Path in the originating request.
  The "to URL" field corresponds to HTTP Header "Location" in the server
  Redirect reply.

  A redirects file entry has four fields separated by FIELD_DELIMITER character:
  "from path", "to URL", "added by user", "added on datetime".
  For example,

    /hr http://human-resources.megacorp.local/login     bob     2019-09-07 12:00:00

  The last two fields, "added by user" and "added on datetime", are intended
  for record-keeping within an organization.

  A passed redirect should have a leading "/" as this is the URI path given for
  processing.
  For example, the URL "http://host/hr" is processed as URI path "/hr".

  A redirect will combine the various incoming URI parts.
  For example, given redirect entry:

    /b  http://bug-tracker.megacorp.local/view.cgi      bob     2019-09-07 12:00:00

  And incoming GET or HEAD request:

    http://goto/b?id=123

  will result in a redirect URL:

    http://bug-tracker.megacorp.local/view.cgi?id=123

Redirect Entry Template Syntax ("dynamic" URLs):

  Special substrings with Python string.Template syntax may be set in the
  redirect entry "To" field.

  First, given the URL

     http://host.com/pa/th;parm?a=A&b=B#frag

  the URI parts that form a urllib.urlparse ParseResult class would be:

    ParseResult(scheme='http', netloc='host.com', path='/pa/th',
                params='parm', query='a=A&b=B', fragment='frag')

  So then given redirect entry:

    /b  http://bug-tracker.megacorp.local/view.cgi?id=${query}  bob     2019-09-07 12:00:00

  and the incoming GET or HEAD request:

    http://goto/b?123

  Substring '123' is the 'query' part of the ParseResult. The resultant redirect
  URL would become:

    http://bug-tracker.megacorp.local/view.cgi?id=123

Redirect Entry Required Request Modifiers:

  Ending the Redirect Entry "from path" field with various URI separators allows
  preferences for which Redirect Entry to use. The purpose is to allow
  preferring a different Redirect Entry depending upon the users request.

  Given redirect entries:

    /b? http://bug-tracker.megacorp.local/view.cgi?id=${query}  bob     2019-09-07 12:00:00
    /b  http://bug-tracker.megacorp.local/main  bob     2019-09-07 12:00:00

  and the incoming GET or HEAD request:

    http://goto/b?123

  This will choose the first Redirect Entry and return 'Location' header

    http://bug-tracker.megacorp.local/view.cgi?id=123

  Whereas the incoming GET or HEAD request:

    http://goto/b

  This will choose the second Redirect Entry and return 'Location' header

    http://bug-tracker.megacorp.local/main

  The example combination sends a basic request for '/b' to some static page and
  a particular query request '/b?123' to a particular query path.
  Failed matches will "fallback" to the basic Redirect Entry, e.g. the Entry
  without any Required Request Modifiers.

  A Redirect Entry with Required Request Modifier will not match a request
  without such a modifier.

  Given redirect entries:

    /b? http://bug-tracker.megacorp.local/view.cgi?id=${query}  bob     2019-09-07 12:00:00

  and the incoming GET or HEAD request:

    http://goto/b

  will return 404 NOT FOUND.

  Required Request Modifiers must be at the end of the "from path" field string.
  Required Request Modifiers strings are:

     ';'  for user requests with a parameter.
     '?'  for user requests with a query.
     ';?' for user requests with a parameter and a query.

About Redirect Files:

   A line with a leading "#" will be ignored.

About Reloads:

  Sending a process signal to the running process will cause
  a reload of any files passed via --redirects.  This allows live updating of
  redirect information without disrupting the running server process.
  On Unix, the signal is SIGUSR1.  On Windows, the signal is SIGBREAK.
  On this system, the signal is Signals.SIGUSR1 (30).
  On Unix, use program `kill`.  On Windows, use program `windows-kill.exe`.

  A reload of redirect files may also be requested via passed URL path
  RELOAD_PATH.

About Paths:

  Options --status-path and --reload-path may be passed paths to obscure access
  from unauthorized users. e.g.

      --status-path '/5f660f59-8ae5-4c56-af2f-8951bd3d5ee2'

About this program:

  Modules used are available within the standard CPython distribution.
  Written for Python 3.7 but hacked to run with at least Python 3.5.2.

[jaraco]

Or after release and install, it would allow running with python -m goto_http_redirect_server.

If you're interested in it also running with python -m goto-http-redirect-server, please let me know and I can provide a patch for that behavior as well.

[jtmoon79]

If you're interested in it also running with python -m goto-http-redirect-server

🤔 ...

Good consideration, but I'll leave it as just one invocation text, for simplicity.

[jtmoon79]

Good consideration, but I'll leave it as just one invocation text, for simplicity.

On second thought, go ahead if you're so motivated. Won't hurt.

[jtmoon79]

LGTM merged