Merge branch 'tc-testing-plugin-architecture'

Brenda J. Butler says:

====================
tools: tc-testing: Plugin Architecture

To make tdc.py more general, we are introducing a plugin architecture.

This patch set first organizes the command line parameters, then
introduces the plugin architecture and some example plugins.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/tc-testing/README

@@ -14,11 +14,11 @@ REQUIREMENTS
 
 *  The kernel must have network namespace support
 
-*   The kernel must have veth support available, as a veth pair is created
+*  The kernel must have veth support available, as a veth pair is created
    prior to running the tests.
 
-*  All tc-related features must be built in or available as modules.
-   To check what is required in current setup run:
+*  All tc-related features being tested must be built in or available as
+   modules.  To check what is required in current setup run:
    ./tdc.py -c
 
    Note:
@@ -44,10 +44,13 @@ using the -p option when running tdc:
 RUNNING TDC
 -----------
 
-To use tdc, root privileges are required. tdc will not run otherwise.
+To use tdc, root privileges are required.  This is because the
+commands being tested must be run as root.  The code that enforces
+execution by root uid has been moved into a plugin (see PLUGIN
+ARCHITECTURE, below).
 
-All tests are executed inside a network namespace to prevent conflicts
-within the host.
+If nsPlugin is linked, all tests are executed inside a network
+namespace to prevent conflicts within the host.
 
 Running tdc without any arguments will run all tests. Refer to the section
 on command line arguments for more information, or run:
@@ -59,6 +62,33 @@ output captured from the failing test will be printed immediately following
 the failed test in the TAP output.
 
 
+OVERVIEW OF TDC EXECUTION
+-------------------------
+
+One run of tests is considered a "test suite" (this will be refined in the
+future).  A test suite has one or more test cases in it.
+
+A test case has four stages:
+
+  - setup
+  - execute
+  - verify
+  - teardown
+
+The setup and teardown stages can run zero or more commands.  The setup
+stage does some setup if the test needs it.  The teardown stage undoes
+the setup and returns the system to a "neutral" state so any other test
+can be run next.  These two stages require any commands run to return
+success, but do not otherwise verify the results.
+
+The execute and verify stages each run one command.  The execute stage
+tests the return code against one or more acceptable values.  The
+verify stage checks the return code for success, and also compares
+the stdout with a regular expression.
+
+Each of the commands in any stage will run in a shell instance.
+
+
 USER-DEFINED CONSTANTS
 ----------------------
 
@@ -70,23 +100,132 @@ executed as part of the test. More will be added as test cases require.
 Example:
 	$TC qdisc add dev $DEV1 ingress
 
+The NAMES values are used to substitute into the commands in the test cases.
+
 
 COMMAND LINE ARGUMENTS
 ----------------------
 
 Run tdc.py -h to see the full list of available arguments.
 
--p PATH           Specify the tc executable located at PATH to be used on this
-                  test run
--c                Show the available test case categories in this test file
--c CATEGORY       Run only tests that belong to CATEGORY
--f FILE           Read test cases from the JSON file named FILE
--l [CATEGORY]     List all test cases in the JSON file. If CATEGORY is
-                  specified, list test cases matching that category.
--s ID             Show the test case matching ID
--e ID             Execute the test case identified by ID
--i                Generate unique ID numbers for test cases with no existing
-                  ID number
+usage: tdc.py [-h] [-p PATH] [-D DIR [DIR ...]] [-f FILE [FILE ...]]
+              [-c [CATG [CATG ...]]] [-e ID [ID ...]] [-l] [-s] [-i] [-v]
+              [-d DEVICE] [-n NS] [-V]
+
+Linux TC unit tests
+
+optional arguments:
+  -h, --help            show this help message and exit
+  -p PATH, --path PATH  The full path to the tc executable to use
+  -v, --verbose         Show the commands that are being run
+  -d DEVICE, --device DEVICE
+                        Execute the test case in flower category
+
+selection:
+  select which test cases: files plus directories; filtered by categories
+  plus testids
+
+  -D DIR [DIR ...], --directory DIR [DIR ...]
+                        Collect tests from the specified directory(ies)
+                        (default [tc-tests])
+  -f FILE [FILE ...], --file FILE [FILE ...]
+                        Run tests from the specified file(s)
+  -c [CATG [CATG ...]], --category [CATG [CATG ...]]
+                        Run tests only from the specified category/ies, or if
+                        no category/ies is/are specified, list known
+                        categories.
+  -e ID [ID ...], --execute ID [ID ...]
+                        Execute the specified test cases with specified IDs
+
+action:
+  select action to perform on selected test cases
+
+  -l, --list            List all test cases, or those only within the
+                        specified category
+  -s, --show            Display the selected test cases
+  -i, --id              Generate ID numbers for new test cases
+
+netns:
+  options for nsPlugin(run commands in net namespace)
+
+  -n NS, --namespace NS
+                        Run commands in namespace NS
+
+valgrind:
+  options for valgrindPlugin (run command under test under Valgrind)
+
+  -V, --valgrind        Run commands under valgrind
+
+
+PLUGIN ARCHITECTURE
+-------------------
+
+There is now a plugin architecture, and some of the functionality that
+was in the tdc.py script has been moved into the plugins.
+
+The plugins are in the directory plugin-lib.  The are executed from
+directory plugins.  Put symbolic links from plugins to plugin-lib,
+and name them according to the order you want them to run.
+
+Example:
+
+bjb@bee:~/work/tc-testing$ ls -l plugins
+total 4
+lrwxrwxrwx  1 bjb  bjb    27 Oct  4 16:12 10-rootPlugin.py -> ../plugin-lib/rootPlugin.py
+lrwxrwxrwx  1 bjb  bjb    25 Oct 12 17:55 20-nsPlugin.py -> ../plugin-lib/nsPlugin.py
+-rwxr-xr-x  1 bjb  bjb     0 Sep 29 15:56 __init__.py
+
+The plugins are a subclass of TdcPlugin, defined in TdcPlugin.py and
+must be called "SubPlugin" so tdc can find them.  They are
+distinguished from each other in the python program by their module
+name.
+
+This base class supplies "hooks" to run extra functions.  These hooks are as follows:
+
+pre- and post-suite
+pre- and post-case
+pre- and post-execute stage
+adjust-command (runs in all stages and receives the stage name)
+
+The pre-suite hook receives the number of tests and an array of test ids.
+This allows you to dump out the list of skipped tests in the event of a
+failure during setup or teardown stage.
+
+The pre-case hook receives the ordinal number and test id of the current test.
+
+The adjust-command hook receives the stage id (see list below) and the
+full command to be executed.  This allows for last-minute adjustment
+of the command.
+
+The stages are identified by the following strings:
+
+  - pre  (pre-suite)
+  - setup
+  - command
+  - verify
+  - teardown
+  - post (post-suite)
+
+
+To write a plugin, you need to inherit from TdcPlugin in
+TdcPlugin.py.  To use the plugin, you have to put the
+implementation file in plugin-lib, and add a symbolic link to it from
+plugins.  It will be detected at run time and invoked at the
+appropriate times.  There are a few examples in the plugin-lib
+directory:
+
+  - rootPlugin.py:
+      implements the enforcement of running as root
+  - nsPlugin.py:
+      sets up a network namespace and runs all commands in that namespace
+  - valgrindPlugin.py
+      runs each command in the execute stage under valgrind,
+      and checks for leaks.
+      This plugin will output an extra test for each test in the test file,
+      one is the existing output as to whether the test passed or failed,
+      and the other is a test whether the command leaked memory or not.
+      (This one is a preliminary version, it may not work quite right yet,
+      but the overall template is there and it should only need tweaks.)
 
 
 ACKNOWLEDGEMENTS

tools/testing/selftests/tc-testing/TODO.txt

@@ -5,6 +5,27 @@ tc Testing Suite To-Do list:
 
 - Add support for multiple versions of tc to run successively
 
-- Improve error messages when tdc aborts its run
+- Improve error messages when tdc aborts its run.  Partially done - still
+  need to better handle problems in pre- and post-suite.
 
-- Allow tdc to write its results to file
+- Use python logger module for debug/verbose output
+
+- Allow tdc to write its results to file.
+  Maybe use python logger module for this too.
+
+- A better implementation of the "hooks".  Currently, every plugin
+  will attempt to run a function at every hook point.  Could be
+  changed so that plugin __init__ methods will register functions to
+  be run in the various predefined times.  Then if a plugin does not
+  require action at a specific point, no penalty will be paid for
+  trying to run a function that will do nothing.
+
+- Proper exception handling - make an exception class and use it
+
+- a TestCase class, for easier testcase handling, searching, comparison
+
+- a TestSuite class
+  and a way to configure a test suite,
+  to automate running multiple "test suites" with different requirements
+
+- super simple test case example using ls, touch, etc

tools/testing/selftests/tc-testing/TdcPlugin.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+class TdcPlugin:
+    def __init__(self):
+        super().__init__()
+        print(' -- {}.__init__'.format(self.sub_class))
+
+    def pre_suite(self, testcount, testidlist):
+        '''run commands before test_runner goes into a test loop'''
+        self.testcount = testcount
+        self.testidlist = testidlist
+        if self.args.verbose > 1:
+            print(' -- {}.pre_suite'.format(self.sub_class))
+
+    def post_suite(self, index):
+        '''run commands after test_runner completes the test loop
+        index is the last ordinal number of test that was attempted'''
+        if self.args.verbose > 1:
+            print(' -- {}.post_suite'.format(self.sub_class))
+
+    def pre_case(self, test_ordinal, testid):
+        '''run commands before test_runner does one test'''
+        if self.args.verbose > 1:
+            print(' -- {}.pre_case'.format(self.sub_class))
+        self.args.testid = testid
+        self.args.test_ordinal = test_ordinal
+
+    def post_case(self):
+        '''run commands after test_runner does one test'''
+        if self.args.verbose > 1:
+            print(' -- {}.post_case'.format(self.sub_class))
+
+    def pre_execute(self):
+        '''run command before test-runner does the execute step'''
+        if self.args.verbose > 1:
+            print(' -- {}.pre_execute'.format(self.sub_class))
+
+    def post_execute(self):
+        '''run command after test-runner does the execute step'''
+        if self.args.verbose > 1:
+            print(' -- {}.post_execute'.format(self.sub_class))
+
+    def adjust_command(self, stage, command):
+        '''adjust the command'''
+        if self.args.verbose > 1:
+            print(' -- {}.adjust_command {}'.format(self.sub_class, stage))
+
+        # if stage == 'pre':
+        #     pass
+        # elif stage == 'setup':
+        #     pass
+        # elif stage == 'execute':
+        #     pass
+        # elif stage == 'verify':
+        #     pass
+        # elif stage == 'teardown':
+        #     pass
+        # elif stage == 'post':
+        #     pass
+        # else:
+        #     pass
+
+        return command
+
+    def add_args(self, parser):
+        '''Get the plugin args from the command line'''
+        self.argparser = parser
+        return self.argparser
+
+    def check_args(self, args, remaining):
+        '''Check that the args are set correctly'''
+        self.args = args
+        if self.args.verbose > 1:
+            print(' -- {}.check_args'.format(self.sub_class))