WebStack

docs/Webware/NOTES.txt

658:be6a7047f3f8
2007-09-27 paulb [project @ 2007-09-27 17:47:19 by paulb] Updated notes on the deployment tool.
     1 Webware's CGI Adapter
     2 =====================
     3 
     4 Copy the Webware/WebKit/Adapters/WebKit.cgi file to your CGI directory (eg.
     5 /home/httpd/cgi-bin) and ensure that the permissions are appropriate for a CGI
     6 program.
     7 
     8 Configuring in Apache
     9 ---------------------
    10 
    11 Add a line like this to your Apache configuration file (eg. httpd.conf):
    12 
    13 ScriptAlias /webkit "/home/httpd/cgi-bin/WebKit.cgi"
    14 
    15 Configuring in AOLserver
    16 ------------------------
    17 
    18 NOTE: AOLserver does not seem to handle "URL encoded" character values
    19 NOTE: properly when such values appear in the path before the query string.
    20 
    21 Ensure the presence of the following lines in your configuration file (eg.
    22 config.tcl):
    23 
    24 ns_section "ns/server/${servername}/module/nscgi"
    25 ns_param   map "GET  /webkit /home/httpd/cgi-bin/WebKit.cgi" ;# CGI script file dir (GET).
    26 ns_param   map "POST /webkit /home/httpd/cgi-bin/WebKit.cgi" ;# CGI script file dir (POST).
    27 ns_param   interps CGIinterps
    28 
    29 ns_section "ns/interps/CGIinterps"
    30 ns_param   .cgi "/usr/bin/python"
    31 
    32 See docs/CGI/NOTES.txt for more information on AOLserver and CGI
    33 configuration.
    34 
    35 Patches for CGIAdapter when working with AOLserver
    36 --------------------------------------------------
    37 
    38 AOLserver appears to set empty CONTENT_LENGTH environment variable values. A
    39 patch for CGIAdapter.py in WebKit can be applied as follows (with a suitable
    40 relative path to WebStack from Webware/WebKit):
    41 
    42 cd Webware/WebKit
    43 patch -p0 < ../../WebStack/patches/Webware/WebKit/CGIAdapter.py.diff
    44 
    45 Authentication/Authorisation in Webware
    46 =======================================
    47 
    48 Since Webware provides some kind of CGI emulation environment, the actual HTTP
    49 headers involved with authentication/authorisation are not available to the
    50 WebStack transaction. Therefore, WebStack depends on Webware having access to
    51 the REMOTE_USER environment variable set by the Web server, and with Apache,
    52 this variable is only ever set when Apache itself has performed
    53 authentication. Whilst applications can send the "WWW-Authenticate" header to
    54 HTTP clients, unless Apache has been instructed to process the resulting
    55 username/password information, the REMOTE_USER will apparently remain
    56 undefined.
    57 
    58 Consequently, it is recommended that the following kind of definition is added
    59 to httpd.conf (for Apache) in order to give applications access to
    60 username/password details:
    61 
    62 <Location "/webkit/auth">
    63     AuthType Basic
    64     AuthName "AuthResource"
    65     AuthUserFile /usr/local/apache2/conf/users
    66     require valid-user
    67 </Location>
    68 
    69 The details of the application's deployment, including the exact pathname of
    70 the users file and the appropriate access policy, must obviously be defined
    71 according to the actual application concerned.
    72 
    73 Note that the above example will only apply authentication to either a
    74 specific context (for Webware releases beyond 0.8.1) and only to a specific
    75 "region" of possible URLs (for Webware 0.8.1 and earlier).
    76 
    77 For Webware Releases Beyond 0.8.1
    78 =================================
    79 
    80 WebStack applications are supported as contexts within WebKit, meaning that a
    81 certain prefix in the URL determines whether an application is sent a
    82 particular request.
    83 
    84 Each context must be defined in the Webware/WebKit/Configs/Application.config
    85 file within the 'Contexts' dictionary; for example:
    86 
    87 Contexts['simple'] = '/home/paulb/Software/Python/WebStack/examples/Webware/SimpleContext'
    88 
    89 Note that the path to the context directory must be absolute, although the
    90 context directory may reside within WebKit itself such that the path may then
    91 make use of the special WebKitPath variable.
    92 
    93 Note also that the name of the context (eg. 'simple') must not be the same as
    94 the name of any other package used within the application (and possibly any
    95 other applications in the application server), with the only reasonable
    96 exception being the context package name itself (eg. 'SimpleContext').
    97 Otherwise, the existing package will become overridden by the contents of the
    98 context itself.  Therefore, given that the Simple package is used to hold the
    99 actual application code, it is not wise to use 'Simple' as the context name.
   100 
   101 Running the application server:
   102 
   103 Change into the WebKit directory within Webware. Then, specifying the
   104 appropriate PYTHONPATH, invoke the application server. For example:
   105 
   106 PYTHONPATH=../../WebStack:../../WebStack/examples/Common ./AppServer
   107 
   108 The WebStack package must reside on the PYTHONPATH, along with the package
   109 containing the application itself.
   110 
   111 For Webware 0.8.1 or Earlier
   112 ============================
   113 
   114 Support for WebStack applications is provided by a Webware plug-in which
   115 associates Webware resources having certain suffixes with certain WebStack
   116 applications, regardless of the context within which a resource appears. In
   117 order to make use of such a scheme, a WebStack application would have its
   118 resources residing in an arbitrary URL "hierarchy", but with each resource
   119 having the special suffix to indicate that it belongs to that application.
   120 
   121 In the case of an application whose chosen suffix is ".xyz", it would be
   122 possible, for example, to define resources residing at the following URL
   123 paths:
   124 
   125   tasks/my-tasks.xyz
   126   tasks/outstanding/urgent.xyz
   127   agenda/today.xyz
   128 
   129 This is somewhat counter-intuitive to typical Webware concepts, and it is
   130 recommended that Webware releases beyond 0.8.1 are used together with the
   131 appropriate WebStack context mechanisms instead of using this plug-in scheme.
   132 
   133 In order to support such behaviour, some patches must be applied to WebKit
   134 (with a suitable relative path to WebStack from Webware/WebKit):
   135 
   136 cd Webware/WebKit
   137 patch -p0 < ../../WebStack/patches/Webware/WebKit/Application.py-0.8.1.diff
   138 patch -p0 < ../../WebStack/patches/Webware/WebKit/HTTPRequest.py-0.8.1.diff
   139 
   140 Each plug-in, representing a WebStack application, should be visible in the
   141 Webware root directory. A symbolic link can be used to make each example
   142 appear; the Simple application being installed as follows:
   143 
   144 cd Webware
   145 ln -s ../WebStack/examples/Webware/SimpleApp
   146 
   147 Configuring the application server:
   148 
   149 Ensure that the ExtraPathInfo parameter in WebKit/Configs/Application.config
   150 is set to 0.
   151 
   152 Running the application server:
   153 
   154 Change into the WebKit directory within Webware. Then, specifying the
   155 appropriate PYTHONPATH, invoke the application server. For example:
   156 
   157 PYTHONPATH=../../WebStack:../../WebStack/examples/Common ./AppServer
   158 
   159 The WebStack package must reside on the PYTHONPATH, along with the package
   160 containing the application itself.