Add is_int_like() function

Some OpenStack projects (like Cinder, Ironic, Nova) have similar
is_int_like() function so it's would be nice to keep it in common
code. oslo.utils seems to be the proper place for this.

Change-Id: Ieb76a32e8ad9fe80bbb8ce9d1c4860a594a2893e

oslo/utils/strutils.py

@@ -245,3 +245,16 @@ def mask_password(message, secret="***"):
         message = re.sub(pattern, substitute, message)
 
     return message
+
+
+def is_int_like(val):
+    """Check if a value looks like an integer with base 10.
+
+    :param val: Value to verify
+    :type val: string
+    :returns: bool
+    """
+    try:
+        return six.text_type(int(val)) == six.text_type(val)
+    except (TypeError, ValueError):
+        return False

tests/test_strutils.py

@@ -550,3 +550,29 @@ class MaskPasswordTestCase(test_base.BaseTestCase):
         payload = "test = cmd --password my\xe9\x80\x80pass"
         expected = ("test = cmd --password ***")
         self.assertEqual(expected, strutils.mask_password(payload))
+
+
+class IsIntLikeTestCase(test_base.BaseTestCase):
+    def test_is_int_like_true(self):
+        self.assertTrue(strutils.is_int_like(1))
+        self.assertTrue(strutils.is_int_like("1"))
+        self.assertTrue(strutils.is_int_like("514"))
+        self.assertTrue(strutils.is_int_like("0"))
+
+    def test_is_int_like_false(self):
+        self.assertFalse(strutils.is_int_like(1.1))
+        self.assertFalse(strutils.is_int_like("1.1"))
+        self.assertFalse(strutils.is_int_like("1.1.1"))
+        self.assertFalse(strutils.is_int_like(None))
+        self.assertFalse(strutils.is_int_like("0."))
+        self.assertFalse(strutils.is_int_like("aaaaaa"))
+        self.assertFalse(strutils.is_int_like("...."))
+        self.assertFalse(strutils.is_int_like("1g"))
+        self.assertFalse(
+            strutils.is_int_like("0cc3346e-9fef-4445-abe6-5d2b2690ec64"))
+        self.assertFalse(strutils.is_int_like("a1"))
+        # NOTE(viktors): 12e3 - is a float number
+        self.assertFalse(strutils.is_int_like("12e3"))
+        # NOTE(viktors): Check integer numbers with base not 10
+        self.assertFalse(strutils.is_int_like("0o51"))
+        self.assertFalse(strutils.is_int_like("0xDEADBEEF"))