From a201265f871c45eb5ee44b90fea1cf4d2ce81e39 Mon Sep 17 00:00:00 2001
From: "Piotr F. Mieszkowski" <pfm@disroot.org>
Date: Wed, 19 Jan 2022 21:57:46 +0100
Subject: [PATCH] Rework how E2E tests are executed

Tests kept breaking (not failing) randomly with "Broken pipe" errors.  Rework
how processes are spawned to make sure that it doesn't break them again.
---
 test/e2e_test.py | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/test/e2e_test.py b/test/e2e_test.py
index a3617d6..efc9e3c 100644
--- a/test/e2e_test.py
+++ b/test/e2e_test.py
@@ -20,6 +20,8 @@
 import os
 import sys
 
+import subprocess
+
 import difflib
 
 import configparser
@@ -70,7 +72,7 @@ def load_file(name):
 	contents = f.read()
 	f.close()
 
-	return contents
+	return bytes(contents, 'utf-8')
 
 def report_result(message_file, expected, test_output):
     status = None
@@ -91,23 +93,35 @@ def execute_e2e_test(case_name, config, config_path):
     # This environment variable is set in Makefile.
     python_path = os.getenv('PYTHON', 'python3')
 
-    test_command = "GPG_MAILGATE_CONFIG=%s %s gpg-mailgate.py %s < %s" % (
-        config_path,
-        python_path,
-        config.get(case_name, "to"),
-        config.get(case_name, "in"))
-    result_command = "%s %s %d" % (python_path, config.get("relay", "script"), config.getint("relay", "port"))
+    gpglacre_cmd = [python_path,
+                    "gpg-mailgate.py",
+                    config.get(case_name, "to")]
 
-    logging.debug("Spawning relay: '%s'" % (result_command))
-    pipe = os.popen(result_command, 'r')
+    relay_cmd = [python_path,
+                 config.get("relay", "script"),
+                 config.get("relay", "port")]
 
-    logging.debug("Spawning GPG-Lacre: '%s'" % (test_command))
-    msgin = os.popen(test_command, 'w')
-    msgin.write(load_file(config.get(case_name, "in")))
-    msgin.close()
+    logging.debug("Spawning relay: '%s'" % (relay_cmd))
+    relay_proc = subprocess.Popen(relay_cmd,
+                                  stdin = None,
+                                  stdout = subprocess.PIPE)
 
-    testout = pipe.read()
-    pipe.close()
+    logging.debug("Spawning GPG-Lacre: '%s', stdin = %s"
+                  % (gpglacre_cmd,
+                     config.get(case_name, "in")))
+
+    # pass PATH because otherwise it would be dropped
+    gpglacre_proc = subprocess.run(gpglacre_cmd,
+                                   input = load_file(config.get(case_name, "in")),
+                                   capture_output = True,
+                                   env = {"GPG_MAILGATE_CONFIG": config_path,
+                                          "PATH": os.getenv("PATH")})
+
+    # Let the relay process the data.
+    relay_proc.wait()
+
+    (testout, _) = relay_proc.communicate()
+    testout = testout.decode('utf-8')
 
     logging.debug("Read %d characters of test output: '%s'" % (len(testout), testout))