Fix random test failures

"test_networkbench: increase resolution time tolerance" addresses [this](https://erp5.nexedi.net/test_result_module/20200911-8C18D791/14):

```
======================================================================
FAIL: test_dnsbench_fail (slapos.test.test_networkbench.TestDNSBench)
Test dns failure resolution
----------------------------------------------------------------------
Traceback (most recent call last):
File "/srv/slapgrid/slappart20/srv/testnode/cum/inst/test0-0/parts/slapos.toolbox/slapos/test/test_networkbench.py", line 66, in test_dnsbench_fail
self.assertLess(info[3], 1)
AssertionError: 2.0736539363861084 not less than 1
```

"cpu load plugin: fix test and minor cleanups" addresses [this](https://erp5.nexedi.net/test_result_module/20200911-C444DB47/13):

```
======================================================================
ERROR: test_check_cpu_load_run (slapos.test.promise.plugin.test_check_server_cpu_load.TestCheckServerCPULoad)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/srv/slapgrid/slappart9/srv/testnode/bvi/inst/test0-0/parts/slapos.toolbox/slapos/test/promise/plugin/test_check_server_cpu_load.py", line 48, in test_check_cpu_load_run
    self.launcher.run()
  File "/srv/slapgrid/slappart9/srv/testnode/bvi/soft/65dbbd3d11daa99cf78c9566a0a4798e/parts/slapos.core-repository/slapos/grid/promise/__init__.py", line 884, in run
    failed_promise_output))
PromiseError: Promise 'server-cpu-load-promise.py' failed with output: Error: Promise timed out after 0.5 seconds
```
Some more fixes are in slapos!809

See merge request !85

slapos/promise/plugin/check_server_cpu_load.py

@@ -4,6 +4,7 @@ from slapos.grid.promise.generic import GenericPromise
 
 import subprocess
 import os
+import psutil
 
 @implementer(interface.IPromise)
 class RunPromise(GenericPromise):
@@ -14,13 +15,9 @@ class RunPromise(GenericPromise):
     self.setPeriodicity(minute=3)
 
   def checkCPULoad(self, tolerance=2.2):
-
     # tolerance=1.5 => accept CPU load up to 1.5 =150%
-    uptime_result = subprocess.check_output('uptime', universal_newlines=True)
-    line = uptime_result.strip().split(' ')
-    load, load5, long_load = line[-3:]
-    long_load = float(long_load.replace(',', '.'))
-    core_count = int(subprocess.check_output('nproc').strip())
+    load, load5, long_load = psutil.getloadavg()
+    core_count = psutil.cpu_count()
     max_load = core_count * tolerance
     if long_load > max_load:
       # display top statistics
@@ -51,9 +48,9 @@ class RunPromise(GenericPromise):
     self.checkCPULoad(threshold or 2.2)
 
   def test(self):
-    # fail if load is high than the threshold for more than 30 minutes
+    # fail if load is higher than the threshold for more than 30 minutes
     return self._test(result_count=10, failure_amount=10)
 
   def anomaly(self):
-    # fail if load is high than the threshold for more than 30 minutes
+    # fail if load is higher than the threshold for more than 30 minutes
     return self._test(result_count=10, failure_amount=10)

slapos/test/promise/plugin/test_check_server_cpu_load.py

@@ -32,7 +32,7 @@ import os
 class TestCheckServerCPULoad(TestPromisePluginMixin):
 
   def setUp(self):
-    TestPromisePluginMixin.setUp(self)
+    super(TestCheckServerCPULoad, self).setUp()
     self.promise_name = "server-cpu-load-promise.py"
 
     content = """from slapos.promise.plugin.check_server_cpu_load import RunPromise
@@ -44,13 +44,10 @@ extra_config_dict = {
     self.writePromise(self.promise_name, content)
 
   def test_check_cpu_load_run(self):
-    self.configureLauncher()
+    self.configureLauncher(timeout=5)
     self.launcher.run()
     result = self.getPromiseResult(self.promise_name)
     if result['result']['failed']:
       self.assertTrue("CPU load is high" in result['result']['message'])
     else:
       self.assertEqual("CPU load is OK", result['result']['message'].strip())
-
-if __name__ == '__main__':
-  unittest.main()

slapos/test/test_networkbench.py

@@ -47,7 +47,7 @@ class TestDNSBench(unittest.TestCase):
     self.assertEqual(info[1], 'eu.web.vifib.com')
     self.assertEqual(info[2], 200)
 
-    self.assertLess(info[3], 1)
+    self.assertLess(info[3], 30)
     self.assertEqual(info[4], 'OK', 
           "%s != OK, full info: %s" % (info[4], info) )
     self.assertEqual(set(info[5]), set([u'85.118.38.162', u'176.31.129.213']),
@@ -63,7 +63,7 @@ class TestDNSBench(unittest.TestCase):
     self.assertEqual(info[1], 'thisdomaindontexist.erp5.com')
     self.assertEqual(info[2], 600)
 
-    self.assertLess(info[3], 1)
+    self.assertLess(info[3], 30)
     self.assertEqual(info[4], 'Cannot resolve the hostname')
     self.assertEqual(info[5], [])
 
@@ -77,7 +77,7 @@ class TestDNSBench(unittest.TestCase):
     self.assertEqual(info[1], 'www.erp5.com')
     self.assertEqual(info[2], 200)
 
-    self.assertLess(info[3], 1)
+    self.assertLess(info[3], 30)
     self.assertEqual(info[4], 'UNEXPECTED')
     self.assertTrue(info[5].startswith("['85.118.38.162'] (expected) != "))
 
@@ -207,37 +207,3 @@ class TestHTTPBench(unittest.TestCase):
     self.assertEqual(info[2], 200)
     self.assertEqual(len(info[3].split(';')), 5 )
     self.assertEqual(info[4], "UNEXPECTED (COUSCOUS not in page content)")
-
-
-
-#def request(url, expected_dict):
-#  
-#  rendering_time = "%s;%s;%s;%s;%s" % \
-#    (curl.getinfo(curl.NAMELOOKUP_TIME),
-#     curl.getinfo(curl.CONNECT_TIME),
-#     curl.getinfo(curl.PRETRANSFER_TIME),
-#     curl.getinfo(curl.STARTTRANSFER_TIME),
-#     curl.getinfo(curl.TOTAL_TIME))
-#  
-#  response_code = curl.getinfo(pycurl.HTTP_CODE)
-#
-#  expected_response = expected_dict.get("expected_response", None)
-#  if expected_response is not None and \
-#      expected_response != response_code:
-#    result = "UNEXPECTED (%s != %s)" % (expected_response, response_code)
-#
-#  expected_text = expected_dict.get("expected_text", None)
-#  if expected_text is not None and \
-#      str(expected_text) not in str(body):
-#    result = "UNEXPECTED (%s not in page content)" % (expected_text)
-#
-#
-#  info_list = ('GET', url, response_code, rendering_time, result)
-#
-#  return info_list
-#
-
-
-  
-if __name__ == '__main__':
-  unittest.main()