Debugged extra_specs_ops.py

The current extra_specs_ops.py under nova/scheduler/filters has a bug:
it crahses if <or> is not followed by a word. For example, if
"<or> gpu <or>" is given in extra_specs, current code tries to pop a
word after the second <or> that causes a crash. This patch lets it
ignore the "<or>" keyword if no word follows the second "<or>" keyword.

Debugged bug 1038979

Change-Id: I80a6eafd7ee57a2f3ccbf2fb869655ab84e92cf2

nova/scheduler/filters/extra_specs_ops.py

@@ -18,7 +18,7 @@
 # 1. The following operations are supported:
 #   =, s==, s!=, s>=, s>, s<=, s<, <in>, <or>, ==, !=, >=, <=
 # 2. Note that <or> is handled in a different way below.
-# 3. If the first word in the capability is not one of the operators,
+# 3. If the first word in the extra_specs is not one of the operators,
 #   it is ignored.
 _op_methods = {'=': lambda x, y: float(x) >= float(y),
                '<in>': lambda x, y: y in x,
@@ -54,7 +54,9 @@ def match(value, req):
                 return True
             if not words:
                 break
-            op = words.pop(0)
+            op = words.pop(0)  # remove a keyword <or>
+            if not words:
+                break
         return False
 
     if words and method(value, words[0]):

nova/tests/scheduler/test_host_filters.py

@@ -670,24 +670,48 @@ def test_compute_filter_passes_extra_specs_with_op_in2(self):
             especs={'opt1': '<in> 12311321'},
             passes=True)
 
+    def test_compute_filter_passes_extra_specs_with_op_in3(self):
+        self._do_test_compute_filter_extra_specs(
+            ecaps={'opt1': '12311321'},
+            especs={'opt1': '<in> 12311321 <in>'},
+            passes=True)
+
     def test_compute_filter_fails_extra_specs_with_op_in(self):
         self._do_test_compute_filter_extra_specs(
             ecaps={'opt1': '12310321'},
             especs={'opt1': '<in> 11'},
             passes=False)
 
+    def test_compute_filter_fails_extra_specs_with_op_in2(self):
+        self._do_test_compute_filter_extra_specs(
+            ecaps={'opt1': '12310321'},
+            especs={'opt1': '<in> 11 <in>'},
+            passes=False)
+
     def test_compute_filter_passes_extra_specs_with_op_or(self):
         self._do_test_compute_filter_extra_specs(
             ecaps={'opt1': '12'},
             especs={'opt1': '<or> 11 <or> 12'},
             passes=True)
 
+    def test_compute_filter_passes_extra_specs_with_op_or2(self):
+        self._do_test_compute_filter_extra_specs(
+            ecaps={'opt1': '12'},
+            especs={'opt1': '<or> 11 <or> 12 <or>'},
+            passes=True)
+
     def test_compute_filter_fails_extra_specs_with_op_or(self):
         self._do_test_compute_filter_extra_specs(
             ecaps={'opt1': '13'},
             especs={'opt1': '<or> 11 <or> 12'},
             passes=False)
 
+    def test_compute_filter_fails_extra_specs_with_op_or2(self):
+        self._do_test_compute_filter_extra_specs(
+            ecaps={'opt1': '13'},
+            especs={'opt1': '<or> 11 <or> 12 <or>'},
+            passes=False)
+
     def test_compute_filter_passes_extra_specs_with_op_le(self):
         self._do_test_compute_filter_extra_specs(
             ecaps={'opt1': 2, 'opt2': 2},