Enable in-process func tests to optionally use fast-post

Running functional tests in the in-process mode uses
the default value for proxy-server object_post_as_copy,
which is True. This patch adds support for an environment
variable to change this value to False so that the fast-post
mode is tested when running in-process functional tests.

The patch also adds a new tox environment func-in-process-fast-post
which forces in-process functional testing with
object_post_as_copy=False.

The motivation for this change, apart from enabling configurable
local testing, is to put support in place for an upstream CI job
that will actually functionally test the fast-post mode, which is
otherwise only covered by unit tests.

There are currently two gate jobs that run the functional tests:

- gate-swift-dsvm-functional runs the tests *twice* against a
  devstack swift service, once using tempauth and once using
  keystoneauth. The devstack swift service uses the default
  object_post_as_copy=True.

- gate-swift-tox-func runs the func tests in in-process mode
  which also uses tempauth and object_post_as_copy=True. This
  duplicates one of the config scenarios above.

With this change either the gate-swift-tox-func job or a new job
could run the functional tests using object_post_as_copy=False.

Change-Id: Ia37f6df1dc38e44ef7404fbf0a52f6fc22fae0c2

doc/source/development_guidelines.rst

@@ -83,15 +83,35 @@ For example, this command would run the functional tests using policy
 
   SWIFT_TEST_POLICY=silver tox -e func
 
+
+In-process functional testing
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 If the ``test.conf`` file is not found then the functional test framework will
 instantiate a set of Swift servers in the same process that executes the
 functional tests. This 'in-process test' mode may also be enabled (or disabled)
 by setting the environment variable ``SWIFT_TEST_IN_PROCESS`` to a true (or
 false) value prior to executing `tox -e func`.
 
-When using the 'in-process test' mode, the optional in-memory
-object server may be selected by setting the environment variable
-``SWIFT_TEST_IN_MEMORY_OBJ`` to a true value.
+When using the 'in-process test' mode some server configuration options may be
+set using environment variables:
+
+- the optional in-memory object server may be selected by setting the
+  environment variable ``SWIFT_TEST_IN_MEMORY_OBJ`` to a true value.
+
+- the proxy-server ``object_post_as_copy`` option may be set using the
+  environment variable ``SWIFT_TEST_IN_PROCESS_OBJECT_POST_AS_COPY``.
+
+For example, this command would run the in-process mode functional tests with
+the proxy-server using object_post_as_copy=False (the 'fast-POST' mode)::
+
+    SWIFT_TEST_IN_PROCESS=1 SWIFT_TEST_IN_PROCESS_OBJECT_POST_AS_COPY=False \
+        tox -e func
+
+This particular example may also be run using the ``func-in-process-fast-post``
+tox environment::
+
+    tox -e func-in-process-fast-post
 
 The 'in-process test' mode searches for ``proxy-server.conf`` and
 ``swift.conf`` config files from which it copies config options and overrides
@@ -127,7 +147,7 @@ using config files found in ``$HOME/my_tests`` and policy 'silver'::
 Coding Style
 ------------
 
-Swift use flake8 with the OpenStack `hacking`_ module to enforce
+Swift uses flake8 with the OpenStack `hacking`_ module to enforce
 coding style.
 
 Install flake8 and hacking with pip or by the packages of your

test/functional/__init__.py

@@ -388,6 +388,15 @@ def in_process_setup(the_object_server=object_server):
         'SERVICE_require_group': 'service'
     })
 
+    # If an env var explicitly specifies the proxy-server object_post_as_copy
+    # option then use its value, otherwise leave default config unchanged.
+    object_post_as_copy = os.environ.get(
+        'SWIFT_TEST_IN_PROCESS_OBJECT_POST_AS_COPY')
+    if object_post_as_copy is not None:
+        object_post_as_copy = config_true_value(object_post_as_copy)
+        config['object_post_as_copy'] = str(object_post_as_copy)
+        _debug('Setting object_post_as_copy to %r' % object_post_as_copy)
+
     acc1lis = eventlet.listen(('localhost', 0))
     acc2lis = eventlet.listen(('localhost', 0))
     con1lis = eventlet.listen(('localhost', 0))

tox.ini

@@ -44,6 +44,11 @@ commands =
 [testenv:func]
 commands = ./.functests {posargs}
 
+[testenv:func-in-process-fast-post]
+commands = ./.functests {posargs}
+setenv = SWIFT_TEST_IN_PROCESS=1
+         SWIFT_TEST_IN_PROCESS_OBJECT_POST_AS_COPY=False
+
 [testenv:venv]
 commands = {posargs}