Changes between Version 3 and Version 4 of TracFineGrainedPermissions


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Timestamp:
2013-05-22T09:31:17+02:00 (14 months ago)
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trac
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  • TracFineGrainedPermissions

    v3 v4  
     1[[PageOutline(2-5, Contents, floated)]] 
    12= Fine grained permissions = 
    23 
    34Before Trac 0.11, it was only possible to define fine-grained permissions checks on the repository browser sub-system. 
    45 
    5 Since 0.11, there's a general mechanism in place that allows custom permission policy plugins to grant or deny any action on any kind of Trac resources, even at the level of specific versions of such resources. 
     6Since 0.11, there's a general mechanism in place that allows custom **permission policy plugins** to grant or deny any action on any kind of Trac resources, even at the level of specific versions of such resources. 
     7 
     8Note that for Trac 0.12, `authz_policy` has been integrated as an optional module (in `tracopt.perm.authz_policy.*`), so it's installed by default and can simply be activated via the //Plugins// panel in the Trac administration module. 
     9 
    610 
    711== Permission Policies == 
    812 
    9 === !AuthzPolicy === 
    10  
    11 An example policy based on an Authz-style system has been added. See 
    12 [trac:source:branches/0.11-stable/sample-plugins/permissions/authz_policy.py authz_policy.py] for details (current version requires >= Python 2.4). (See also [trac:source:branches/0.11-stable/sample-plugins/permissions sample-plugins/permissions] for more samples.) 
    13  
    14  - Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (required). 
    15  - Copy authz_policy.py into your plugins directory. 
    16  - Put a [http://swapoff.org/files/authzpolicy.conf authzpolicy.conf] file somewhere (preferably on a secured location on the server, not readable for others than the webuser. 
    17  - Update your `trac.ini`: 
    18    1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section 
     13A great diversity of permission policies can be implemented, and Trac comes with a few examples.  
     14 
     15Which policies are currently active is determined by a configuration setting in TracIni: 
     16e.g. 
     17{{{ 
     18[trac] 
     19permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
     20}}} 
     21This lists the [#AuthzSourcePolicy] described below as the first policy, followed by the !DefaultPermissionPolicy which checks for the traditional coarse grained style permissions described in TracPermissions, and the !LegacyAttachmentPolicy which knows how to use the coarse grained permissions for checking the permissions available on attachments. 
     22 
     23Among the possible optional choices, there is [#AuthzPolicy], a very generic permission policy, based on an Authz-style system. See 
     24[trac:source:branches/0.12-stable/tracopt/perm/authz_policy.py authz_policy.py] for details.  
     25 
     26Another popular permission policy [#AuthzSourcePolicy], re-implements the pre-0.12 support for checking fine-grained permissions limited to Subversion repositories in terms of the new system. 
     27 
     28See also [trac:source:branches/0.12-stable/sample-plugins/permissions sample-plugins/permissions] for more examples. 
     29 
     30 
     31=== !AuthzPolicy ===  
     32==== Configuration ==== 
     33* Install [http://www.voidspace.org.uk/python/configobj.html ConfigObj] (still needed for 0.12). 
     34* Copy authz_policy.py into your plugins directory (only for Trac 0.11). 
     35* Put a [http://swapoff.org/files/authzpolicy.conf authzpolicy.conf] file somewhere, preferably on a secured location on the server, not readable for others than the webuser. If the  file contains non-ASCII characters, the UTF-8 encoding should be used. 
     36* Update your `trac.ini`: 
     37  1. modify the [TracIni#trac-section permission_policies] entry in the `[trac]` section 
    1938{{{ 
    2039[trac] 
     
    2241permission_policies = AuthzPolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
    2342}}} 
    24    2. add a new `[authz_policy]` section 
     43  1. add a new `[authz_policy]` section 
    2544{{{ 
    2645[authz_policy] 
    2746authz_file = /some/trac/env/conf/authzpolicy.conf 
    2847}}} 
    29    3. enable the single file plugin 
     48  1. enable the plugin through [/admin/general/plugin WebAdmin] or by editing the `[components]` section 
    3049{{{ 
    3150[components] 
    3251... 
    33 authz_policy.* = enabled 
    34 }}} 
    35  
     52# Trac 0.12 
     53tracopt.perm.authz_policy.* = enabled 
     54# for Trac 0.11 use this 
     55#authz_policy.* = enabled  
     56}}} 
     57 
     58 
     59==== Usage Notes ==== 
    3660Note that the order in which permission policies are specified is quite critical,  
    3761as policies will be examined in the sequence provided. 
    3862 
    39 A policy will return either `True`, `False` or `None` for a given permission check. 
    40 Only if the return value is `None` will the ''next'' permission policy be consulted. 
    41 If no policy explicitly grants the permission, the final result will be `False`  
    42 (i.e. no permission). 
     63A policy will return either `True`, `False` or `None` for a given permission check. `True` is returned if the policy explicitly grants the permission. `False` is returned if the policy explicitly denies the permission. `None` is returned if the policy is unable to either grant or deny the permission. 
     64 
     65NOTE: Only if the return value is `None` will the ''next'' permission policy be consulted. 
     66If none of the policies explicitly grants the permission, the final result will be `False`  
     67(i.e. permission denied). 
     68 
     69The `authzpolicy.conf` file is a `.ini` style configuration file: 
     70{{{ 
     71[wiki:PrivatePage@*] 
     72john = WIKI_VIEW, !WIKI_MODIFY 
     73jack = WIKI_VIEW 
     74* = 
     75}}} 
     76* Each section of the config is a glob pattern used to match against a Trac resource 
     77  descriptor. These descriptors are in the form: 
     78{{{ 
     79<realm>:<id>@<version>[/<realm>:<id>@<version> ...] 
     80}}} 
     81  Resources are ordered left to right, from parent to child. If any 
     82  component is inapplicable, `*` is substituted. If the version pattern is 
     83  not specified explicitely, all versions (`@*`) is added implicitly 
     84 
     85  Example: Match the WikiStart page 
     86{{{ 
     87[wiki:*] 
     88[wiki:WikiStart*] 
     89[wiki:WikiStart@*] 
     90[wiki:WikiStart] 
     91}}} 
     92 
     93  Example: Match the attachment `wiki:WikiStart@117/attachment/FOO.JPG@*` 
     94  on WikiStart 
     95{{{ 
     96[wiki:*] 
     97[wiki:WikiStart*] 
     98[wiki:WikiStart@*] 
     99[wiki:WikiStart@*/attachment/*] 
     100[wiki:WikiStart@117/attachment/FOO.JPG] 
     101}}} 
     102 
     103* Sections are checked against the current Trac resource descriptor '''IN ORDER''' of 
     104  appearance in the configuration file. '''ORDER IS CRITICAL'''. 
     105 
     106* Once a section matches, the current username is matched against the keys  
     107  (usernames) of the section, '''IN ORDER'''.  
     108  * If a key (username) is prefixed with a `@`, it is treated as a group.  
     109  * If a value (permission) is prefixed with a `!`, the permission is 
     110    denied rather than granted. 
     111 
     112  The username will match any of 'anonymous', 'authenticated', <username> or '*', using normal Trac permission rules. || '''Note:''' Other groups which are created by user (e.g. by 'adding subjects to groups' on web interface page //Admin / Permissions//) cannot be used. See [trac:ticket:5648 #5648] for details about this missing feature || 
    43113 
    44114For example, if the `authz_file` contains: 
     
    49119[wiki:PrivatePage@*] 
    50120john = WIKI_VIEW 
    51 * = 
     121* = !WIKI_VIEW 
    52122}}} 
    53123and the default permissions are set like this: 
     
    59129 
    60130Then:  
    61  - All versions of WikiStart will be viewable by everybody (including anonymous) 
    62  - !PrivatePage will be viewable only by john 
    63  - other pages will be viewable only by john and jack 
    64  
    65  
    66 === mod_authz_svn-like permission policy === 
    67  
    68 At the time of this writing, the old fine grained permissions system from Trac 0.10 and before used for restricting access to the repository has not yet been converted to a permission policy component, but from the user point of view, this makes little if no difference. 
     131  * All versions of WikiStart will be viewable by everybody (including anonymous) 
     132  * !PrivatePage will be viewable only by john 
     133  * other pages will be viewable only by john and jack 
     134 
     135Groups: 
     136{{{ 
     137[groups] 
     138admins = john, jack 
     139devs = alice, bob 
     140 
     141[wiki:Dev@*] 
     142@admins = TRAC_ADMIN 
     143@devs = WIKI_VIEW 
     144* = 
     145 
     146[*] 
     147@admins = TRAC_ADMIN 
     148* = 
     149}}} 
     150 
     151Then: 
     152- everything is blocked (whitelist approach), but 
     153- admins get all TRAC_ADMIN everywhere and 
     154- devs can view wiki pages. 
     155 
     156Some repository examples (Browse Source specific): 
     157{{{ 
     158# A single repository: 
     159[repository:test_repo@*] 
     160john = BROWSER_VIEW, FILE_VIEW 
     161# John has BROWSER_VIEW and FILE_VIEW for the entire test_repo 
     162 
     163# All repositories: 
     164[repository:*@*] 
     165jack = BROWSER_VIEW, FILE_VIEW 
     166# John has BROWSER_VIEW and FILE_VIEW for all repositories 
     167}}} 
     168 
     169Very fine grain repository access: 
     170{{{ 
     171# John has BROWSER_VIEW and FILE_VIEW access to trunk/src/some/location/ only 
     172[repository:test_repo@*/source:trunk/src/some/location/*@*] 
     173john = BROWSER_VIEW, FILE_VIEW 
     174 
     175 
     176# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of all files at trunk/src/some/location only 
     177[repository:test_repo@*/source:trunk/src/some/location/*@1] 
     178john = BROWSER_VIEW, FILE_VIEW 
     179 
     180 
     181# John has BROWSER_VIEW and FILE_VIEW access to all revisions of 'somefile' at trunk/src/some/location only  
     182[repository:test_repo@*/source:trunk/src/some/location/somefile@*] 
     183john = BROWSER_VIEW, FILE_VIEW 
     184 
     185 
     186# John has BROWSER_VIEW and FILE_VIEW access to only revision 1 of 'somefile' at trunk/src/some/location only 
     187[repository:test_repo@*/source:trunk/src/some/location/somefile@1] 
     188john = BROWSER_VIEW, FILE_VIEW 
     189}}} 
     190 
     191Note: In order for Timeline to work/visible for John, we must add CHANGESET_VIEW to the above permission list. 
     192 
     193 
     194==== Missing Features ==== 
     195Although possible with the !DefaultPermissionPolicy handling (see Admin panel), fine-grained permissions still miss those grouping features (see [trac:ticket:9573 #9573], [trac:ticket:5648 #5648]). Patches are partially available, see forgotten authz_policy.2.patch  part of [trac:ticket:6680 #6680]). 
     196 
     197You cannot do the following: 
     198{{{ 
     199[groups] 
     200team1 = a, b, c 
     201team2 = d, e, f 
     202team3 = g, h, i 
     203departmentA = team1, team2 
     204}}} 
     205 
     206Permission groups are not supported either. You cannot do the following: 
     207{{{ 
     208[groups] 
     209permission_level_1 = WIKI_VIEW, TICKET_VIEW 
     210permission_level_2  = permission_level_1, WIKI_MODIFY, TICKET_MODIFY 
     211[*] 
     212@team1 = permission_level_1 
     213@team2 = permission_level_2 
     214@team3 = permission_level_2, TICKET_CREATE 
     215}}} 
     216 
     217=== !AuthzSourcePolicy  (mod_authz_svn-like permission policy) === #AuthzSourcePolicy 
     218 
     219At the time of this writing, the old fine grained permissions system from Trac 0.11 and before used for restricting access to the repository has  been converted to a permission policy component, but from the user point of view, this makes little if no difference. 
    69220 
    70221That kind of fine-grained permission control needs a definition file, which is the one used by Subversion's mod_authz_svn.  
     
    97248}}} 
    98249 
    99 if you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add  
     250If you want to support the use of the `[`''modulename''`:/`''some''`/`''path''`]` syntax within the `authz_file`, add  
    100251 
    101252{{{ 
     
    103254}}} 
    104255 
    105 where ''modulename'' refers to the same repository indicated by the `repository_dir` entry in the `[trac]` section. 
     256where ''modulename'' refers to the same repository indicated by the `repository_dir` entry in the `[trac]` section. As an example, if the `repository_dir` entry in the `[trac]` section is {{{/srv/active/svn/blahblah}}}, that would yield the following: 
     257 
     258{{{  
     259[trac] 
     260authz_file = /path/to/svnaccessfile 
     261authz_module_name = blahblah 
     262... 
     263repository_dir = /srv/active/svn/blahblah  
     264}}} 
     265 
     266where the svn access file, {{{/path/to/svnaccessfile}}}, contains entries such as {{{[blahblah:/some/path]}}}. 
    106267 
    107268'''Note:''' Usernames inside the Authz file __must__ be the same as those used inside trac.  
     269 
     270As of version 0.12, make sure you have ''!AuthzSourcePolicy'' included in the permission_policies list in trac.ini, otherwise the authz permissions file will be ignored. 
     271 
     272{{{  
     273[trac] 
     274permission_policies = AuthzSourcePolicy, DefaultPermissionPolicy, LegacyAttachmentPolicy 
     275}}} 
    108276 
    109277==== Subversion Configuration ==== 
     
    122290For information about how to restrict access to entire projects in a multiple project environment see [trac:wiki:TracMultipleProjectsSVNAccess] 
    123291 
    124 == Getting TracFineGrainedPermissions to work == 
    125  
    126 Don't forget to restart Trac engine to apply new configuration if you are running tracd standalone server. 
     292== Debugging permissions 
     293In trac.ini set: 
     294{{{ 
     295[logging] 
     296log_file = trac.log 
     297log_level = DEBUG 
     298log_type = file 
     299}}} 
     300 
     301And watch: 
     302{{{ 
     303tail -n 0 -f log/trac.log | egrep '\[perm\]|\[authz_policy\]' 
     304}}} 
     305 
     306to understand what checks are being performed. See the sourced documentation of the plugin for more info. 
     307 
    127308 
    128309---- 
    129 See also: TracPermissions 
    130 http://trac-hacks.org/wiki/FineGrainedPageAuthzEditorPlugin for a simple editor plugin. 
     310See also: TracPermissions, 
     311[http://trac-hacks.org/wiki/FineGrainedPageAuthzEditorPlugin TracHacks:FineGrainedPageAuthzEditorPlugin] for a simple editor plugin.