Fix url redirection when a remote nextcloud is used so that .well-known/caldav and carddav work properly, as well as the redirecting /cloud to the remote Nextcloud. Since the nginx config is replaced by the management daemon whenever a new domain is added, this change adds a hooking mechanism for setup mods.Fix url redirection when a remote nextcloud is in use. This corrects redirection for /.well-known/caldav, /.well-known/carddav and /cloud to send the client to the remote nextcloud. This requires an nginx configuration change, and since the nginx config is replaced by the management daemon whenever a new domain is added, this change adds a hooking mechanism for setup mods allowing them to intercept and modify the resultant nginx config.

setup/mods.available/hooks/remote-nextcloud-mgmt-hooks.py

@@ -0,0 +1,63 @@
+
+#
+# This is a web_update management hook for the remote-nextcloud setup
+# mod.
+#
+# When management/web_update.py creates a new nginx configuration file
+# "local.conf", this mod will ensure that .well-known/caldav and
+# .well-known/carddav urls are redirected to the remote nextcloud.
+#
+# The hook is enabled by placing the file in directory
+# LOCAL_MODS_DIR/managment_hooks_d.
+#
+
+import os
+import logging
+
+log = logging.getLogger(__name__)
+
+
+def do_hook(hook_name, hook_data, mods_env):
+    if hook_name != 'web_update':
+        # we only care about hooking web_update
+        log.debug('hook - ignoring %s' % hook_name)
+        return False
+
+    if 'NC_HOST' not in mods_env or mods_env['NC_HOST'].strip() == '':
+        # not configured for a remote nextcloud
+        log.debug('hook - not configured for a remote nextcloud')
+        return False
+    
+    # get the remote nextcloud url and ensure no tailing /
+    nc_url = "%s://%s:%s%s" % (
+        mods_env['NC_PROTO'],
+        mods_env['NC_HOST'],
+        mods_env['NC_PORT'],
+        mods_env['NC_PREFIX'][0:-1] if mods_env['NC_PREFIX'].endswith('/') else mods_env['NC_PREFIX']
+    )
+
+    #
+    # modify nginx_conf
+    #
+    def do_replace(find_str, replace_with):
+        if hook_data['nginx_conf'].find(find_str) == -1:
+            log.warning('remote-nextcloud hook: string "%s" not found in proposed nginx_conf' % (find_str))
+            return False
+        hook_data['nginx_conf'] = hook_data['nginx_conf'].replace(
+            find_str,
+            replace_with
+        )
+        return True
+            
+    # 1. change the .well-known/(caldav|carddav) redirects
+    do_replace(
+        '/cloud/remote.php/dav/',
+        '%s/remote.php/dav/' % nc_url
+    )
+    
+    # 2. redirect /cloud to the remote nextcloud
+    do_replace(
+        'rewrite ^/cloud/$ /cloud/index.php;',
+        'rewrite ^/cloud/(.*)$ %s/$1 redirect;' % nc_url
+    )
+