Add missing swift constraint for functional tests

Looks like we are keeping at least four lists of the default
constraints in various places, and when we added the max_header_size
in initial Static Large Object Support commit (5d73da1) we failed to
add it to the two locations in the test tree (test/sample.conf and
test/functional/tests.py).

With this commit we take a small step to consolidate the list of
constraints to the constraints module by removing the list from the
tests module (note we still have them listed in the sample swift.conf
file and the test module's sample.conf file), document the missing
reference in the test module's sample.conf file, and, while we're at
it, use the SWIFT_CONF_FILE reference where possible.

Change-Id: Ic4fa5f1aedec9bc7a7b43ce1a2ca3cdebce6171f

swift/common/constraints.py

@@ -18,12 +18,12 @@
 from urllib import unquote
 from ConfigParser import ConfigParser, NoSectionError, NoOptionError
 
-from swift.common.utils import ismount, split_path
+from swift.common.utils import ismount, split_path, SWIFT_CONF_FILE
 from swift.common.swob import HTTPBadRequest, HTTPLengthRequired, \
     HTTPRequestEntityTooLarge, HTTPPreconditionFailed
 
 constraints_conf = ConfigParser()
-constraints_conf.read('/etc/swift/swift.conf')
+constraints_conf_exists = constraints_conf.read(SWIFT_CONF_FILE)
 
 
 def constraints_conf_int(name, default):
@@ -58,6 +58,21 @@ def constraints_conf_int(name, default):
 #: Max container name length
 MAX_CONTAINER_NAME_LENGTH = constraints_conf_int('max_container_name_length',
                                                  256)
+# A simple dictionary of all the constraints that can be specified in the
+# SWIFT_CONF_FILE.
+default_constraints = dict((
+    ('max_file_size', MAX_FILE_SIZE),
+    ('max_meta_name_length', MAX_META_NAME_LENGTH),
+    ('max_meta_value_length', MAX_META_VALUE_LENGTH),
+    ('max_meta_count', MAX_META_COUNT),
+    ('max_meta_overall_size', MAX_META_OVERALL_SIZE),
+    ('max_header_size', MAX_HEADER_SIZE),
+    ('max_object_name_length', MAX_OBJECT_NAME_LENGTH),
+    ('container_listing_limit', CONTAINER_LISTING_LIMIT),
+    ('account_listing_limit', ACCOUNT_LISTING_LIMIT),
+    ('max_account_name_length', MAX_ACCOUNT_NAME_LENGTH),
+    ('max_container_name_length', MAX_CONTAINER_NAME_LENGTH)))
+
 # Maximum slo segments in buffer
 MAX_BUFFERED_SLO_SEGMENTS = 10000
 

test/functional/tests.py

@@ -25,40 +25,19 @@
 import uuid
 import unittest
 from nose import SkipTest
-from ConfigParser import ConfigParser
 
 from test import get_config
 from test.functional.swift_test_client import Account, Connection, File, \
     ResponseError
-from swift.common.constraints import MAX_FILE_SIZE, MAX_META_NAME_LENGTH, \
-    MAX_META_VALUE_LENGTH, MAX_META_COUNT, MAX_META_OVERALL_SIZE, \
-    MAX_OBJECT_NAME_LENGTH, CONTAINER_LISTING_LIMIT, ACCOUNT_LISTING_LIMIT, \
-    MAX_ACCOUNT_NAME_LENGTH, MAX_CONTAINER_NAME_LENGTH
-
-default_constraints = dict((
-    ('max_file_size', MAX_FILE_SIZE),
-    ('max_meta_name_length', MAX_META_NAME_LENGTH),
-    ('max_meta_value_length', MAX_META_VALUE_LENGTH),
-    ('max_meta_count', MAX_META_COUNT),
-    ('max_meta_overall_size', MAX_META_OVERALL_SIZE),
-    ('max_object_name_length', MAX_OBJECT_NAME_LENGTH),
-    ('container_listing_limit', CONTAINER_LISTING_LIMIT),
-    ('account_listing_limit', ACCOUNT_LISTING_LIMIT),
-    ('max_account_name_length', MAX_ACCOUNT_NAME_LENGTH),
-    ('max_container_name_length', MAX_CONTAINER_NAME_LENGTH)))
-constraints_conf = ConfigParser()
-conf_exists = constraints_conf.read('/etc/swift/swift.conf')
-# Constraints are set first from the test config, then from
-# /etc/swift/swift.conf if it exists. If swift.conf doesn't exist,
-# then limit test coverage. This allows SAIO tests to work fine but
-# requires remote functional testing to know something about the cluster
-# that is being tested.
+from swift.common.constraints import default_constraints, \
+    constraints_conf_exists
+
 config = get_config('func_test')
 for k in default_constraints:
     if k in config:
         # prefer what's in test.conf
         config[k] = int(config[k])
-    elif conf_exists:
+    elif constraints_conf_exists:
         # swift.conf exists, so use what's defined there (or swift defaults)
         # This normally happens when the test is running locally to the cluster
         # as in a SAIO.

test/sample.conf

@@ -25,15 +25,17 @@ password2 = testing2
 username3 = tester3
 password3 = testing3
 
-# Default constraints if not defined here, the test runner will try
-# to set them from /etc/swift/swift.conf. If that file isn't found,
-# the test runner will skip tests that depend on these values.
+# If not defined here, the test runner will try to use the default constraint
+# values as constructed by the constraints module, which will attempt to get
+# them from /etc/swift/swift.conf, if possible. Then, if the swift.conf file
+# isn't found, the test runner will skip tests that depend on those values.
 # Note that the cluster must have "sane" values for the test suite to pass.
 #max_file_size = 5368709122
 #max_meta_name_length = 128
 #max_meta_value_length = 256
 #max_meta_count = 90
 #max_meta_overall_size = 4096
+#max_header_size = 8192
 #max_object_name_length = 1024
 #container_listing_limit = 10000
 #account_listing_limit = 10000