Adding a new optional variable called trans_id_suffix

The trans_id_suffix (default is empty) would be appended to the swift transaction
id allowing one to easily figure out from which cluster that X-Trans-Id
belongs to. This is very useful when one is managing more than one swift
cluster. Also updated sample and manpage to reflect the changes.

Change-Id: Icdf63643e9c1bde36a9ef5e3f41ee9fb20e55f5d

doc/manpages/proxy-server.conf.5

@@ -78,6 +78,10 @@ Syslog log facility. The default is LOG_LOCAL0.
 Logging level. The default is INFO.
 .IP \fBlog_address\fR
 Logging address. The default is /dev/log.
+.IP \fBtrans_id_suffix\fR
+This optional suffix (default is empty) that would be appended to the swift transaction
+id allows one to easily figure out from which cluster that X-Trans-Id belongs to.
+This is very useful when one is managing more than one swift cluster.
 .RE
 .PD
 
@@ -431,7 +435,7 @@ Python regular expressions of substrings that will not be allowed in a name.
 
 
 .RS 0
-.IP "\fB[filter:proxy_logging]\fR"
+.IP "\fB[filter:proxy-logging]\fR"
 .RE
 
 Logging for the proxy server now lives in this middleware.

etc/proxy-server.conf-sample

@@ -16,6 +16,11 @@
 # log_level = INFO
 # log_headers = False
 # log_address = /dev/log
+# This optional suffix (default is empty) that would be appended to the swift transaction
+# id allows one to easily figure out from which cluster that X-Trans-Id belongs to.
+# This is very useful when one is managing more than one swift cluster.
+# trans_id_suffix =
+#
 # comma separated list of functions to call to setup custom log handlers.
 # functions get passed: conf, name, log_to_console, log_route, fmt, logger,
 # adapted_logger
@@ -340,6 +345,7 @@ use = egg:swift#proxy_logging
 # What HTTP methods are allowed for StatsD logging (comma-sep); request methods
 # not in this list will have "BAD_METHOD" for the <verb> portion of the metric.
 # log_statsd_valid_http_methods = GET,HEAD,POST,PUT,DELETE,COPY,OPTIONS
+#
 # Note: The double proxy-logging in the pipeline is not a mistake. The
 # left-most proxy-logging is there to log requests that were handled in
 # middleware and never made it through to the right-most middleware (and

swift/common/middleware/catch_errors.py

@@ -23,12 +23,13 @@ from swift.common.wsgi import WSGIContext
 
 class CatchErrorsContext(WSGIContext):
 
-    def __init__(self, app, logger):
+    def __init__(self, app, logger, trans_id_suffix=''):
         super(CatchErrorsContext, self).__init__(app)
         self.logger = logger
+        self.trans_id_suffix = trans_id_suffix
 
     def handle_request(self, env, start_response):
-        trans_id = 'tx' + uuid.uuid4().hex
+        trans_id = 'tx' + uuid.uuid4().hex + self.trans_id_suffix
         env['swift.trans_id'] = trans_id
         self.logger.txn_id = trans_id
         try:
@@ -60,12 +61,15 @@ class CatchErrorMiddleware(object):
     def __init__(self, app, conf):
         self.app = app
         self.logger = get_logger(conf, log_route='catch-errors')
+        self.trans_id_suffix = conf.get('trans_id_suffix', '')
 
     def __call__(self, env, start_response):
         """
         If used, this should be the first middleware in pipeline.
         """
-        context = CatchErrorsContext(self.app, self.logger)
+        context = CatchErrorsContext(self.app,
+                                     self.logger,
+                                     self.trans_id_suffix)
         return context.handle_request(env, start_response)
 
 

swift/proxy/server.py

@@ -63,6 +63,7 @@ class Application(object):
         self.put_queue_depth = int(conf.get('put_queue_depth', 10))
         self.object_chunk_size = int(conf.get('object_chunk_size', 65536))
         self.client_chunk_size = int(conf.get('client_chunk_size', 65536))
+        self.trans_id_suffix = conf.get('trans_id_suffix', '')
         self.error_suppression_interval = \
             int(conf.get('error_suppression_interval', 60))
         self.error_suppression_limit = \
@@ -210,7 +211,7 @@ class Application(object):
             controller = controller(self, **path_parts)
             if 'swift.trans_id' not in req.environ:
                 # if this wasn't set by an earlier middleware, set it now
-                trans_id = 'tx' + uuid.uuid4().hex
+                trans_id = 'tx' + uuid.uuid4().hex + self.trans_id_suffix
                 req.environ['swift.trans_id'] = trans_id
                 self.logger.txn_id = trans_id
             req.headers['x-trans-id'] = req.environ['swift.trans_id']

test/unit/common/middleware/test_except.py

@@ -82,5 +82,16 @@ class TestCatchErrors(unittest.TestCase):
         resp = app(req.environ, start_response)
         self.assertEquals(list(resp), ['An error occurred'])
 
+    def test_trans_id_header_suffix(self):
+        self.assertEquals(self.logger.txn_id, None)
+
+        def start_response(status, headers, exc_info=None):
+            self.assert_('x-trans-id' in (x[0] for x in headers))
+        app = catch_errors.CatchErrorMiddleware(
+            FakeApp(), {'trans_id_suffix': '-stuff'})
+        req = Request.blank('/v1/a/c/o')
+        app(req.environ, start_response)
+        self.assertTrue(self.logger.txn_id.endswith('-stuff'))
+
 if __name__ == '__main__':
     unittest.main()