Python MapScript via WSGI example

README.md

Overview

Simple example of MapServer MapScript Python via WSGI testing

Environment

• MapServer 6.4.2
• Ubuntu 14.04

Running

python ./mapscript-wsgi.py
# open "http://localhost:8000/?service=WMS&version=1.3.0&request=GetCapabilities"
# open "http://localhost:8000/?service=WMS&version=1.1.1&request=GetMap&layers=CURRENT_CONDITIONS&srs=EPSG:4326&bbox=-180,-90,180,90&format=image/png&width=500&height=300"

apache.conf

WSGIDaemonProcess foo processes=10 threads=1
Alias /ms-wsgi /tmp/foo/mapscript-wsgi.py
<Directory "/tmp/foo">
        AllowOverride None
        Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
        AddHandler wsgi-script .py
        Order Allow,Deny
        Allow from all
</Directory>

mapscript-wsgi.py

import os
import sys

import mapscript


# List of all environment variable used by MapServer
MAPSERV_ENV = [
  'CONTENT_LENGTH', 'CONTENT_TYPE', 'CURL_CA_BUNDLE', 'HTTP_COOKIE',
  'HTTP_HOST', 'HTTPS', 'HTTP_X_FORWARDED_HOST', 'HTTP_X_FORWARDED_PORT',
  'HTTP_X_FORWARDED_PROTO', 'MS_DEBUGLEVEL', 'MS_ENCRYPTION_KEY',
  'MS_ERRORFILE', 'MS_MAPFILE', 'MS_MAPFILE_PATTERN', 'MS_MAP_NO_PATH',
  'MS_MAP_PATTERN', 'MS_MODE', 'MS_OPENLAYERS_JS_URL', 'MS_TEMPPATH',
  'MS_XMLMAPFILE_XSLT', 'PROJ_LIB', 'QUERY_STRING', 'REMOTE_ADDR',
  'REQUEST_METHOD', 'SCRIPT_NAME', 'SERVER_NAME', 'SERVER_PORT'
]


def application(env, start_response):
    for key in MAPSERV_ENV:
        if key in env:
            os.environ[key] = env[key]
        else:
            os.unsetenv(key)

    mapfile = '/tmp/foo.map'
    mapfile = mapscript.mapObj(mapfile)

    request = mapscript.OWSRequest()
    mapscript.msIO_installStdoutToBuffer()
    request.loadParamsFromURL(env['QUERY_STRING'])

    try:
        status = mapfile.OWSDispatch(request)
    except Exception as err:
        pass

    content_type = mapscript.msIO_stripStdoutBufferContentType()
    result = mapscript.msIO_getStdoutBufferBytes()
    start_response('200 OK', [('Content-type', content_type)])
    return [result]

if __name__ == '__main__':  # run inline using WSGI reference implementation
    from wsgiref.simple_server import make_server
    port = 8001
    if len(sys.argv) > 1:
        port = int(sys.argv[1])
    httpd = make_server('', port, application)
    print('Serving on port %d...' % port)
    httpd.serve_forever()

Glad you found this useful @jmckenna! And great to see in MS4W moving forward.