tkt-77377: Treat stdout being closed as not a tty (#880)

* Treat stdout being closed as not a tty

FreeNAS Ticket: #77377

* Make is_tty a method in ioc_common

* Travis

*ding*!

iocage_lib/ioc_common.py

@@ -66,7 +66,7 @@ def callback(_log, callback_exception):
         log.log(25, message)
     elif level == 'EXCEPTION':
         try:
-            if not os.isatty(sys.stdout.fileno()):
+            if not is_tty():
                 raise callback_exception(message)
             else:
                 if not isinstance(message, str) and isinstance(
@@ -918,3 +918,13 @@ def construct_truthy(item, inverse=False):
         return (f'{item}=off', f'{item}=no', f'{item}=0', f'{item}=false')
 
     return (f'{item}=on', f'{item}=yes', f'{item}=1', f'{item}=true')
+
+
+def is_tty():
+    """Returns True or False if stdout is a tty"""
+    try:
+        is_tty = os.isatty(sys.stdout.fileno())
+    except ValueError:
+        is_tty = False
+
+    return is_tty

iocage_lib/iocage.py

@@ -28,7 +28,6 @@
 import operator
 import os
 import subprocess as su
-import sys
 
 import iocage_lib.ioc_clean as ioc_clean
 import iocage_lib.ioc_common as ioc_common
@@ -853,7 +852,7 @@ def exec(self,
         status, jid = self.list("jid", uuid=uuid)
 
         if not status and not start_jail:
-            if not os.isatty(sys.stdout.fileno()):
+            if not ioc_common.is_tty():
                 ioc_common.logit(
                     {
                         "level": "EXCEPTION",
@@ -1209,7 +1208,7 @@ def get(
                 return state
             elif plugin:
                 if not status and not start_jail:
-                    if not os.isatty(sys.stdout.fileno()):
+                    if not ioc_common.is_tty():
                         ioc_common.logit(
                             {
                                 "level": "EXCEPTION",