Skip failing execute tests when using /tmp noexec

test_retry_on_failure and test_no_retry_on_success from
ExecuteTestCase are failing when running system with /tmp noexec.
These tests should be skipped in this case.

Related-bug: #1359463
Change-Id: I32fa8f90a6292229bd23eec6d648fab617e59ec3

ironic_python_agent/tests/utils.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import errno
 import os
 import tempfile
 import testtools
@@ -52,11 +53,18 @@ exit 1
 ''')
             fp.close()
             os.chmod(tmpfilename, 0o755)
+            try:
                 self.assertRaises(processutils.ProcessExecutionError,
                                   utils.execute,
                                   tmpfilename, tmpfilename2, attempts=10,
                                   process_input='foo',
                                   delay_on_retry=False)
+            except OSError as e:
+                if e.errno == errno.EACCES:
+                    self.skipTest("Permissions error detected. "
+                                  "Are you running with a noexec /tmp?")
+                else:
+                    raise
             fp = open(tmpfilename2, 'r')
             runs = fp.read()
             fp.close()
@@ -97,10 +105,17 @@ grep foo
 ''')
             fp.close()
             os.chmod(tmpfilename, 0o755)
+            try:
                 utils.execute(tmpfilename,
                               tmpfilename2,
                               process_input='foo',
                               attempts=2)
+            except OSError as e:
+                if e.errno == errno.EACCES:
+                    self.skipTest("Permissions error detected. "
+                                  "Are you running with a noexec /tmp?")
+                else:
+                    raise
         finally:
             os.unlink(tmpfilename)
             os.unlink(tmpfilename2)