Add global random seed config

This is needed to make fuzzy tests work with xdist as each
xdist gateway expects to receive the same set of parameter
values, which for random generators may be achieved only by
providing globally shared seed.

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

tests/functional/tests/utils/random.py

@@ -36,6 +36,8 @@ class DefaultRanges(Range, enum.Enum):
 
 class RandomGenerator:
     def __init__(self, base_range=DefaultRanges.INT, count=1000):
+        with open("config/random.cfg") as f:
+            self.random = random.Random(int(f.read()))
         self.exclude = []
         self.range = base_range
         self.count = count
@@ -53,7 +55,7 @@ class RandomGenerator:
             raise StopIteration()
         self.n += 1
         while True:
-            val = random.randint(self.range.min, self.range.max)
+            val = self.random.randint(self.range.min, self.range.max)
             if self.exclude:
                 excl_map = map(lambda e: e.is_within(val), self.exclude)
                 is_excluded = reduce(lambda a, b: a or b, excl_map)
@@ -64,6 +66,8 @@ class RandomGenerator:
 
 class RandomStringGenerator:
     def __init__(self, len_range=Range(0, 20), count=700):
+        with open("config/random.cfg") as f:
+            self.random = random.Random(int(f.read()))
         self.generator = self.__string_generator(len_range)
         self.count = count
         self.n = 0
@@ -78,7 +82,7 @@ class RandomStringGenerator:
                       string.punctuation,
                       string.hexdigits]:
                 yield ''.join(random.choice(t) for _ in range(
-                    random.randint(len_range.min, len_range.max)
+                    self.random.randint(len_range.min, len_range.max)
                 ))
 
     def __iter__(self):