support/testing: python-varlink: new runtime test

Add new runtime test for python-varlink.

As always when we need to start a separate server process inside a test
case this gets slightly fiddly.

We override the test_run() function to first start the varlink example server,
then call the packages cli interface to do a varlink call against the
server. The cli defaults to pretty printing the result, which makes it
more annoying to compare to the expected result in the test case, so we
un-prettyprint it with python's builtin json.tool module.

Signed-off-by: Marcus Hoffmann <buildroot@bubu1.eu>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/package/test_python_varlink.py

@@ -0,0 +1,30 @@
+import os
+
+from tests.package.test_python import TestPythonPackageBase
+
+
+class TestPythonPy3Varlink(TestPythonPackageBase):
+    __test__ = True
+    config = TestPythonPackageBase.config + \
+        """
+        BR2_PACKAGE_PYTHON3=y
+        BR2_PACKAGE_PYTHON_VARLINK=y
+        """
+    sample_scripts = ["tests/package/test_python_varlink/sample_python_varlink.py",
+                      "tests/package/test_python_varlink/org.example.test.varlink"]
+
+    def test_run(self):
+        self.login()
+        self.check_sample_scripts_exist()
+        # we need to supress any output here as otherwise the commnd output parsing
+        # gets confused for the second command
+        cmd = "%s %s  > /dev/null 2>&1 &" % (self.interpreter, os.path.basename(self.sample_scripts[0]))
+
+        _, exit_code = self.emulator.run(cmd, timeout=self.timeout)
+
+        varlink_cli_call = "-m varlink.cli call 'unix:@test/org.example.test.Ping' '{\"ping\": \"hello\"}'"
+        unprettyprint = "| python -m json.tool --compact"
+        cmd = "%s %s %s" % (self.interpreter, varlink_cli_call, unprettyprint)
+        output, exit_code = self.emulator.run(cmd, timeout=self.timeout)
+        self.assertEqual(exit_code, 0)
+        self.assertEqual(output[0], '{"pong":"hello"}')

support/testing/tests/package/test_python_varlink/org.example.test.varlink

@@ -0,0 +1,5 @@
+# Example Varlink service
+interface org.example.test
+
+# Returns the same string
+method Ping(ping: string) -> (pong: string)

support/testing/tests/package/test_python_varlink/sample_python_varlink.py

@@ -0,0 +1,24 @@
+import os
+
+import varlink
+
+service = varlink.Service(interface_dir=os.path.dirname(__file__))
+
+
+class ServiceRequestHandler(varlink.RequestHandler):
+    service = service
+
+
+@service.interface("org.example.test")
+class Example:
+    def Ping(self, ping):
+        return {"pong": ping}
+
+
+def run_server(address):
+    with varlink.ThreadingServer(address, ServiceRequestHandler) as server:
+        print("Listening on", server.server_address)
+        server.serve_forever()
+
+
+run_server("unix:@test")