Tests: preserving unit.log when run without restart.

Introducing "unit.log.Log" class for "unit.log" file management.
Moving "findall()" function into TestApplicationProto.
Using "os.kill()" to send signals.

test/conftest.py

@@ -22,6 +22,7 @@ from unit.check.regex import check_regex
 from unit.check.tls import check_openssl
 from unit.http import TestHTTP
 from unit.option import option
+from unit.log import Log
 from unit.utils import public_dir
 from unit.utils import waitforfiles
 
@@ -71,7 +72,6 @@ def pytest_addoption(parser):
 
 
 unit_instance = {}
-unit_log_copy = "unit.log.copy"
 _processes = []
 _fds_check = {
     'main': {'fds': 0, 'skip': False},
@@ -165,12 +165,11 @@ def pytest_sessionstart(session):
     option.available = {'modules': {}, 'features': {}}
 
     unit = unit_run()
-    option.temp_dir = unit['temp_dir']
 
     # read unit.log
 
     for i in range(50):
-        with open(unit['temp_dir'] + '/unit.log', 'r') as f:
+        with open(Log.get_path(), 'r') as f:
             log = f.read()
             m = re.search('controller started', log)
 
@@ -216,9 +215,6 @@ def pytest_sessionstart(session):
     if option.restart:
         shutil.rmtree(unit_instance['temp_dir'])
 
-    elif option.save_log:
-        open(unit_instance['temp_dir'] + '/' + unit_log_copy, 'w').close()
-
 
 @pytest.hookimpl(tryfirst=True, hookwrapper=True)
 def pytest_runtest_makereport(item, call):
@@ -269,7 +265,6 @@ def check_prerequisites(request):
 @pytest.fixture(autouse=True)
 def run(request):
     unit = unit_run()
-    option.temp_dir = unit['temp_dir']
 
     option.skip_alerts = [
         r'read signalfd\(4\) failed',
@@ -291,34 +286,25 @@ def run(request):
 
     # prepare log
 
-    with open(
-        unit_instance['log'], 'r', encoding='utf-8', errors='ignore'
-    ) as f:
+    with Log.open(encoding='utf-8') as f:
         log = f.read()
-
-    if not option.restart and option.save_log:
-        with open(unit_instance['temp_dir'] + '/' + unit_log_copy, 'a') as f:
-            f.write(log)
-
-    # remove unit.log
+        Log.set_pos(f.tell())
 
     if not option.save_log and option.restart:
         shutil.rmtree(unit['temp_dir'])
+        Log.set_pos(0)
 
     # clean temp_dir before the next test
 
     if not option.restart:
         _clear_conf(unit['temp_dir'] + '/control.unit.sock', log)
 
-        open(unit['log'], 'w').close()
-
         for item in os.listdir(unit['temp_dir']):
             if item not in [
                 'control.unit.sock',
                 'state',
                 'unit.pid',
                 'unit.log',
-                unit_log_copy,
             ]:
                 path = os.path.join(unit['temp_dir'], item)
 
@@ -439,10 +425,12 @@ def unit_run():
         exit('Could not start unit')
 
     unit_instance['temp_dir'] = temp_dir
-    unit_instance['log'] = temp_dir + '/unit.log'
     unit_instance['control_sock'] = temp_dir + '/control.unit.sock'
     unit_instance['unitd'] = unitd
 
+    option.temp_dir = temp_dir
+    Log.temp_dir = temp_dir
+
     with open(temp_dir + '/unit.pid', 'r') as f:
         unit_instance['pid'] = f.read().rstrip()
 
@@ -489,12 +477,9 @@ def unit_stop():
         return 'Could not terminate unit'
 
 
-def _check_alerts(path=None, log=None):
-    if path is None:
-        path = unit_instance['log']
-
+def _check_alerts(log=None):
     if log is None:
-        with open(path, 'r', encoding='utf-8', errors='ignore') as f:
+        with Log.open(encoding='utf-8') as f:
             log = f.read()
 
     found = False
@@ -526,7 +511,7 @@ def _check_alerts(path=None, log=None):
 
 
 def _print_log(data=None):
-    path = unit_instance['log']
+    path = Log.get_path()
 
     print('Path to unit.log:\n' + path + '\n')
 
@@ -679,7 +664,7 @@ def unit_pid(request):
 
 def pytest_sessionfinish(session):
     if not option.restart and option.save_log:
-        print('Path to unit.log:\n' + unit_instance['log'] + '\n')
+        print('Path to unit.log:\n' + Log.get_path() + '\n')
 
     option.restart = True