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/Makefile

@@ -18,7 +18,7 @@ SRC=$(shell find $(SRCDIR) $(WRAPDIR) -name \*.c)
 OBJS=$(patsubst %.c, %.o, $(SRC))
 OCFLIB=$(ADAPTERDIR)/libocf.so
 
-all: | sync
+all: | sync config_random
 	$(MAKE) $(OCFLIB)
 
 $(OCFLIB): $(OBJS)
@@ -36,6 +36,9 @@ sync:
 	@$(MAKE) -C $(OCFDIR) src O=$(ADAPTERDIR)/ocf
 	@$(MAKE) -C $(OCFDIR) env O=$(ADAPTERDIR)/ocf OCF_ENV=posix
 
+config_random:
+	@python3 utils/configure_random.py
+
 clean:
 	@rm -rf $(OCFLIB) $(OBJS)
 	@echo "  CLEAN "
@@ -46,4 +49,4 @@ distclean: clean
 	@rm -rf $(INCDIR)/ocf
 	@echo "  DISTCLEAN "
 
-.PHONY: all clean sync distclean
+.PHONY: all clean sync config_random distclean

tests/functional/config/random.cfg

@@ -0,0 +1,2 @@
+# This file content will be generated by utils/configure_random.py
+# triggered from the Makefile

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):

tests/functional/utils/configure_random.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python3
+
+#
+# Copyright(c) 2012-2018 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+
+import sys
+import random
+
+
+with open("config/random.cfg", "w") as f:
+    f.write(str(random.randint(0, sys.maxsize)))