support named groups in SAML claim

* support group names in addition to group IDs
* missing groups are automatically created
* comma-separated group values are trimmed

seahub/adfs_auth/backends.py

@@ -20,6 +20,7 @@
 
 from django.conf import settings
 from django.contrib.auth.backends import ModelBackend
+from django.core.cache import cache
 
 from seaserv import ccnet_api, seafile_api
 
@@ -34,6 +35,7 @@
 
 SAML_PROVIDER_IDENTIFIER = getattr(settings, 'SAML_PROVIDER_IDENTIFIER', 'saml')
 SHIBBOLETH_AFFILIATION_ROLE_MAP = getattr(settings, 'SHIBBOLETH_AFFILIATION_ROLE_MAP', {})
+CACHE_KEY_GROUPS = "all_groups_cache"
 
 
 class Saml2Backend(ModelBackend):
@@ -196,9 +198,28 @@ def sync_saml_groups(self, user, attributes):
 
         # support a list of comma-separated IDs as seafile_groups claim
         if len(seafile_groups) == 1 and ',' in seafile_groups[0]:
-            seafile_groups = seafile_groups[0].split(',')
+            seafile_groups = [group.strip() for group in seafile_groups[0].split(',')]
 
-        saml_group_ids = [int(group_id) for group_id in seafile_groups]
+        saml_group_ids = []
+        if all(group_id.isdigit() for group_id in seafile_groups):
+            # all groups are provided as numeric IDs
+            saml_group_ids = [int(group_id) for group_id in seafile_groups]
+        else:
+            # groups are provided as names, try to get current group information from cache
+            all_groups = cache.get(CACHE_KEY_GROUPS)
+            if not all_groups or any(group not in all_groups for group in seafile_groups):
+                # groups not yet cached or missing entry, reload groups from API
+                all_groups = {group.group_name: group.id for group in ccnet_api.get_all_groups(-1, -1)}
+                cache.set(CACHE_KEY_GROUPS, all_groups, 3600)  # cache for 1 hour
+            # create groups which are not yet existing
+            for group in [group_name for group_name in seafile_groups if group_name not in all_groups]:
+                new_group = ccnet_api.create_group(group, 'system admin') # we are not operating in user context here
+                if new_group < 0:
+                    logger.error('failed to create group %s' % group)
+                    return
+                all_groups[group] = new_group
+            # generate numeric IDs from group names
+            saml_group_ids = [id for group, id in all_groups.items() if group in seafile_groups]
 
         joined_groups = ccnet_api.get_groups(user.username)
         joined_group_ids = [g.id for g in joined_groups]