Use Re() for creating regular expressions

It's a fairly common pattern to use regular expression in our tests.
Instead of using the fairly verbose re.compile(), import that function
as Re() instead to allow for more brevity in the test syntax.

(cherry picked from commit ac7127d620)

bin/tests/system/conftest.py

@@ -13,7 +13,7 @@ from functools import partial
 import filecmp
 import os
 from pathlib import Path
-import re
+from re import compile as Re
 import shutil
 import subprocess
 import tempfile
@@ -49,7 +49,7 @@ else:
 
 XDIST_WORKER = os.environ.get("PYTEST_XDIST_WORKER", "")
 FILE_DIR = os.path.abspath(Path(__file__).parent)
-ENV_RE = re.compile(b"([^=]+)=(.*)")
+ENV_RE = Re(b"([^=]+)=(.*)")
 PORT_MIN = 5001
 PORT_MAX = 32767
 PORTS_PER_TEST = 20
@@ -62,10 +62,10 @@ PRIORITY_TESTS = [
     "timeouts/",
     "upforwd/",
 ]
-PRIORITY_TESTS_RE = re.compile("|".join(PRIORITY_TESTS))
+PRIORITY_TESTS_RE = Re("|".join(PRIORITY_TESTS))
 SYSTEM_TEST_DIR_GIT_PATH = "bin/tests/system"
-SYSTEM_TEST_NAME_RE = re.compile(f"{SYSTEM_TEST_DIR_GIT_PATH}" + r"/([^/]+)")
-SYMLINK_REPLACEMENT_RE = re.compile(r"/tests(_.*)\.py")
+SYSTEM_TEST_NAME_RE = Re(f"{SYSTEM_TEST_DIR_GIT_PATH}" + r"/([^/]+)")
+SYMLINK_REPLACEMENT_RE = Re(r"/tests(_.*)\.py")
 
 # ---------------------- Module initialization ---------------------------
 

bin/tests/system/isctest/log/watchlog.py

@@ -14,6 +14,7 @@ from typing import Any, Iterator, List, Match, Optional, Pattern, TextIO, TypeVa
 import abc
 import os
 import re
+from re import compile as Re
 import time
 
 
@@ -213,7 +214,7 @@ class WatchLog(abc.ABC):
             if isinstance(string, Pattern):
                 patterns.append(string)
             elif isinstance(string, str):
-                pattern = re.compile(re.escape(string))
+                pattern = Re(re.escape(string))
                 patterns.append(pattern)
             else:
                 raise WatchLogException(
@@ -256,13 +257,14 @@ class WatchLog(abc.ABC):
         Recommended use:
 
         ```python
+        from re import compile as Re
         import isctest
 
         def test_foo(servers):
             with servers["ns1"].watch_log_from_start() as watcher:
                 watcher.wait_for_line("all zones loaded")
 
-            pattern = re.compile(r"next key event in ([0-9]+) seconds")
+            pattern = Re(r"next key event in ([0-9]+) seconds")
             with servers["ns1"].watch_log_from_here() as watcher:
                 # ... do stuff here ...
                 match = watcher.wait_for_line(pattern)
@@ -321,7 +323,8 @@ class WatchLog(abc.ABC):
         >>> # Different values must be returned depending on which line is
         >>> # found in the log file.
         >>> import tempfile
-        >>> patterns = [re.compile(r"bar ([0-9])"), "qux"]
+        >>> from re import compile as Re
+        >>> patterns = [Re(r"bar ([0-9])"), "qux"]
         >>> with tempfile.NamedTemporaryFile("w") as file:
         ...     print("foo bar 3", file=file, flush=True)
         ...     with WatchLogFromStart(file.name) as watcher:
@@ -443,7 +446,8 @@ class WatchLog(abc.ABC):
         >>> assert ret[1].group(0) == "foo"
 
         >>> import tempfile
-        >>> bar_pattern = re.compile('bar')
+        >>> from re import compile as Re
+        >>> bar_pattern = Re('bar')
         >>> patterns = ['foo', bar_pattern]
         >>> with tempfile.NamedTemporaryFile("w") as file:
         ...     print("bar", file=file, flush=True)

bin/tests/system/xferquota/tests_xferquota.py

@@ -12,6 +12,7 @@
 import glob
 import os
 import re
+from re import compile as Re
 import shutil
 import signal
 import time
@@ -71,7 +72,7 @@ def test_xferquota(named_port, servers):
         isctest.check.rrsets_equal(ns1response.answer, ns2response.answer)
 
     query_and_compare(axfr_msg)
-    pattern = re.compile(
+    pattern = Re(
         f"transfer of 'changing/IN' from 10.53.0.1#{named_port}: "
         f"Transfer completed: .*\\(serial 2\\)"
     )