Add daemon communication test cases

This change adds an automated test harness that will spin up an instance
of the X52 daemon, connect to its command socket, send commands and
validate the responses. This first set of test cases simply validates
the basic configuration file handling. Subsequent commits will enhance
the tests to improve code coverage.

daemon/Makefile.am

@@ -95,6 +95,13 @@ EXTRA_DIST += \
 	daemon/x52dcomm-internal.h \
 	daemon/x52d.conf
 
+# Test cases
+EXTRA_DIST += \
+	daemon/test_daemon_comm.py \
+	daemon/tests/comm/config_args.tc
+
+TESTS += daemon/test_daemon_comm.py
+
 if HAVE_SYSTEMD
 if !IS_MAKE_DISTCHECK
 SED_ARGS = s,%bindir%,$(bindir),g

daemon/test_daemon_comm.py

@@ -0,0 +1,181 @@
+#!/usr/bin/env python3
+"""Test communication with x52d and verify that the behavior is as expected"""
+
+import glob
+import os
+import os.path
+import shlex
+import signal
+import socket
+import subprocess
+import tempfile
+import time
+import sys
+
+class TestCase:
+    """TestCase class handles an individual test case"""
+    def __init__(self, data):
+        """Create a new test case"""
+        self.desc = None
+        self.in_cmd = None
+        self.exp_resp = None
+        self.parse(data)
+
+    def parse(self, data):
+        """Parses a string of the following form:
+           <description>
+           space separated input line, possibly quoted
+           space separated expected response, possibly quoted
+        """
+        self.desc, in_cmd, exp_resp = data.splitlines()
+        self.in_cmd = '\0'.join(shlex.split(in_cmd)).encode() + b'\0'
+        self.exp_resp = '\0'.join(shlex.split(exp_resp)).encode() + b'\0'
+
+    def execute(self, index, cmdsock):
+        """Execute the test case and return the result in TAP format"""
+        def dump_failed(name, value):
+            """Dump the failed test case"""
+            print("# {}".format(name))
+            for argv in value.decode().split('\0'):
+                print("#\t {}".format(argv))
+            print()
+
+        def print_result(passed):
+            """Print the test case result and description"""
+            out = "ok {} - {}".format(index+1, self.desc)
+            if not passed:
+                out = "not " + out
+            print(out)
+
+        cmdsock.send(self.in_cmd)
+        got_resp = cmdsock.recv(1024)
+
+        if got_resp != self.exp_resp:
+            print_result(False)
+            dump_failed("Expected", self.exp_resp)
+            dump_failed("Got", got_resp)
+        else:
+            print_result(True)
+
+
+class Test:
+    """Test class runs a series of unit tests"""
+
+    def __init__(self):
+        """Create a new instance of the Test class"""
+        self.program = self.find_daemon_program()
+        self.tmpdir = tempfile.TemporaryDirectory()
+        self.command = os.path.join(self.tmpdir.name, "x52d.cmd")
+        self.cmdsock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        self.daemon = None
+        self.testcases = []
+
+    def __enter__(self):
+        """Context manager entry"""
+        self.launch_daemon()
+        return self
+
+    def __exit__(self, *exc):
+        """Context manager exit"""
+        self.terminate_daemon()
+        self.tmpdir.cleanup()
+
+    @staticmethod
+    def find_daemon_program():
+        """Find the daemon program. This script should be run from the
+           root of the build directory"""
+        daemon_candidates = glob.glob('**/x52d', recursive=True)
+        if not daemon_candidates:
+            print("Bail out! Unable to find X52 daemon.")
+            sys.exit(1)
+
+        return os.path.realpath(daemon_candidates[0])
+
+    def launch_daemon(self):
+        """Launch an instance of the running daemon"""
+        if self.daemon is not None:
+            # We've already started the daemon, check if it is still running
+            if self.daemon.poll() is None:
+                return
+
+            self.daemon = None
+
+        daemon_cmdline = [
+            self.program,
+            "-f", # Run in foreground
+            "-v", # Verbose logging
+            "-c", os.path.join(self.tmpdir.name, "x52d.cfg"), # Default config file
+            "-l", os.path.join(self.tmpdir.name, "x52d.log"), # Output logs to log file
+            "-p", os.path.join(self.tmpdir.name, "x52d.pid"), # PID file
+            "-s", self.command, # Command socket path
+        ]
+
+        # Create empty config file
+        with open(daemon_cmdline[4], 'w'):
+            pass
+
+        self.daemon = subprocess.Popen(daemon_cmdline)
+
+        print("# Sleeping 2 seconds for daemon to start")
+        time.sleep(2)
+
+        self.cmdsock.connect(self.command)
+
+    def terminate_daemon(self):
+        """Terminate a running daemon"""
+        if self.daemon is None:
+            return
+
+        # Send a SIGTERM to the daemon
+        os.kill(self.daemon.pid, signal.SIGTERM)
+        try:
+            self.daemon.wait(timeout=15)
+        except subprocess.TimeoutExpired:
+            # Forcibly kill the running process
+            self.daemon.kill()
+        finally:
+            self.daemon = None
+            self.cmdsock.close()
+
+    def append(self, testcase):
+        """Add one testcase to the test case list"""
+        self.testcases.append(testcase)
+
+    def extend(self, testcases):
+        """Add one or more testcases to the test case list"""
+        self.testcases.extend(testcases)
+
+    @staticmethod
+    def dump_failed(name, value):
+        """Dump the failed test case"""
+        print("# {}".format(name))
+        for argv in value.decode().split('\0'):
+            print("#\t {}".format(argv))
+        print()
+
+    def run_tests(self):
+        """Run test cases"""
+        print("1..{}".format(len(self.testcases)))
+        for index, testcase in enumerate(self.testcases):
+            testcase.execute(index, self.cmdsock)
+
+    def find_and_parse_testcase_files(self):
+        """Find and parse *.tc files"""
+        basedir = os.path.dirname(os.path.realpath(__file__))
+        pattern = os.path.join(basedir, '**', 'comm', '*.tc')
+        tc_files = glob.glob(pattern, recursive=True)
+
+        for tc_file in tc_files:
+            with open(tc_file) as tc_fd:
+                # Test cases are separated by blank lines
+                testcases = tc_fd.read().split('\n\n')
+                self.extend(TestCase(tc_data) for tc_data in testcases)
+
+def main():
+    """Main routine adds test cases to the Test class and runs them"""
+    with Test() as test:
+        test.find_and_parse_testcase_files()
+        test.run_tests()
+
+if __name__ == '__main__':
+    main()

daemon/tests/comm/config_args.tc

@@ -0,0 +1,63 @@
+Configuration with insufficient arguments
+config
+ERR "Insufficient arguments for 'config' command"
+
+Load with invalid file argument
+config load ''
+ERR "Invalid file '' for 'config load' command"
+
+Load with nonexistent file argument
+config load /nonexistent
+ERR "Invalid file '/nonexistent' for 'config load' command"
+
+Load with empty file argument
+config load /dev/null
+OK config load /dev/null
+
+Load with extra arguments
+config load /dev/null ''
+ERR "Unexpected arguments for 'config load' command; got 4, expected 3"
+
+Load with missing argument
+config load
+ERR "Unexpected arguments for 'config load' command; got 2, expected 3"
+
+Reload configuration
+config reload
+OK config reload
+
+Reload configuration with extra arguments
+config reload ''
+ERR "Unexpected arguments for 'config reload' command; got 3, expected 2"
+
+Dump configuration with insufficient arguments
+config dump
+ERR "Unexpected arguments for 'config dump' command; got 2, expected 3"
+
+Dump configuration with invalid file
+config dump ''
+ERR "Invalid file '' for 'config dump' command"
+
+Dump configuration with extra arguments
+config dump /dev/null ''
+ERR "Unexpected arguments for 'config dump' command; got 4, expected 3"
+
+Dump configuration to /dev/null
+config dump /dev/null
+OK config dump /dev/null
+
+Save configuration
+config save
+OK config save
+
+Save configuration with extra arguments
+config save ''
+ERR "Unexpected arguments for 'config save' command; got 3, expected 2"
+
+Config command with empty subcommand
+config ''
+ERR "Unknown subcommand '' for 'config' command"
+
+Config command with unknown subcommand
+config foo
+ERR "Unknown subcommand 'foo' for 'config' command"