Fix escaping of regular expressions in tox.ini

With the new version of tox, the interpretation of escaping in the
command section changed [1]. For example, the `tox -e smoke` runs the
following command to execute tempest tests when tox==4.3.5. is installed:

tempest run --regex '[.*\bsmoke\b.*]'
(missing '\' in front of '[', ']') ^^

The issue can be fixed either by adding another backslash ('\\[') or
moving the regular expressions to separate variables. The first solution
won't, however, be backwards compatible with the older version of tox
therefore this patch uses the second approach.

[1] https://tox.wiki/en/latest/config.html#substitutions

Change-Id: Ie5ea7f9305c7e7611f205d2e0703849bd6321a68
diff --git a/tox.ini b/tox.ini
index 618f9e0..e1c17df 100644
--- a/tox.ini
+++ b/tox.ini
@@ -132,10 +132,11 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '(^tempest\.scenario.*)|(^tempest\.serial_tests)|(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
 # The regex below is used to select all tempest scenario and including the non slow api tests
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(^tempest\.scenario.*)|(^tempest\.serial_tests)|(?!.*\[.*\bslow\b.*\])(^tempest\.api)' {posargs}
+    tempest run --regex {[testenv:full-parallel]regex} {posargs}
 
 [testenv:api-microversion-tests]
 envdir = .tox/tempest
@@ -143,11 +144,12 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '(^tempest\.api\.compute)|(^tempest\.api\.volume)'
 # The regex below is used to select all tempest api tests for services having API
 # microversion concept.
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(^tempest\.api\.compute)|(^tempest\.api\.volume)' {posargs}
+    tempest run --regex {[testenv:api-microversion-tests]regex} {posargs}
 
 [testenv:integrated-network]
 envdir = .tox/tempest
@@ -155,12 +157,14 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex1 = '(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
+regex2 = '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)'
 # The regex below is used to select which tests to run and exclude the slow tag and
 # tests listed in exclude-list file:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)' --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
+    tempest run --regex {[testenv:integrated-network]regex1} --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex {[testenv:integrated-network]regex2} --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
 
 [testenv:integrated-compute]
 envdir = .tox/tempest
@@ -168,12 +172,14 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex1 = '(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
+regex2 = '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)'
 # The regex below is used to select which tests to run and exclude the slow tag and
 # tests listed in exclude-list file:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-compute-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)' --exclude-list ./tools/tempest-integrated-gate-compute-exclude-list.txt {posargs}
+    tempest run --regex {[testenv:integrated-compute]regex1} --exclude-list ./tools/tempest-integrated-gate-compute-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex {[testenv:integrated-compute]regex2} --exclude-list ./tools/tempest-integrated-gate-compute-exclude-list.txt {posargs}
 
 [testenv:integrated-placement]
 envdir = .tox/tempest
@@ -181,12 +187,14 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex1 = '(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
+regex2 = '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)'
 # The regex below is used to select which tests to run and exclude the slow tag and
 # tests listed in exclude-list file:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-placement-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)' --exclude-list ./tools/tempest-integrated-gate-placement-exclude-list.txt {posargs}
+    tempest run --regex {[testenv:integrated-placement]regex1} --exclude-list ./tools/tempest-integrated-gate-placement-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex {[testenv:integrated-placement]regex2} --exclude-list ./tools/tempest-integrated-gate-placement-exclude-list.txt {posargs}
 
 [testenv:integrated-storage]
 envdir = .tox/tempest
@@ -194,12 +202,14 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex1 = '(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
+regex2 = '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)'
 # The regex below is used to select which tests to run and exclude the slow tag and
 # tests listed in exclude-list file:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-storage-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)' --exclude-list ./tools/tempest-integrated-gate-storage-exclude-list.txt {posargs}
+    tempest run --regex {[testenv:integrated-storage]regex1} --exclude-list ./tools/tempest-integrated-gate-storage-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex {[testenv:integrated-storage]regex2} --exclude-list ./tools/tempest-integrated-gate-storage-exclude-list.txt {posargs}
 
 [testenv:integrated-object-storage]
 envdir = .tox/tempest
@@ -207,12 +217,14 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex1 = '(?!.*\[.*\bslow\b.*\])(^tempest\.api)'
+regex2 = '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)'
 # The regex below is used to select which tests to run and exclude the slow tag and
 # tests listed in exclude-list file:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-object-storage-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)|(^tempest\.serial_tests)' --exclude-list ./tools/tempest-integrated-gate-object-storage-exclude-list.txt {posargs}
+    tempest run --regex {[testenv:integrated-object-storage]regex1} --exclude-list ./tools/tempest-integrated-gate-object-storage-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex {[testenv:integrated-object-storage]regex2} --exclude-list ./tools/tempest-integrated-gate-object-storage-exclude-list.txt {posargs}
 
 [testenv:full-serial]
 envdir = .tox/tempest
@@ -220,12 +232,13 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|serial_tests))'
 # The regex below is used to select which tests to run and exclude the slow tag:
 # See the testrepository bug: https://bugs.launchpad.net/testrepository/+bug/1208610
 # FIXME: We can replace it with the `--exclude-regex` option to exclude tests now.
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|serial_tests))' {posargs}
+    tempest run --serial --regex {[testenv:full-serial]regex} {posargs}
 
 [testenv:scenario]
 envdir = .tox/tempest
@@ -233,10 +246,11 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '(^tempest\.scenario)'
 # The regex below is used to select all scenario tests
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --serial --regex '(^tempest\.scenario)' {posargs}
+    tempest run --serial --regex {[testenv:scenario]regex} {posargs}
 
 [testenv:smoke]
 envdir = .tox/tempest
@@ -244,9 +258,10 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '\[.*\bsmoke\b.*\]'
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '\[.*\bsmoke\b.*\]' {posargs}
+    tempest run --regex {[testenv:smoke]regex} {posargs}
 
 [testenv:smoke-serial]
 envdir = .tox/tempest
@@ -254,12 +269,13 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '\[.*\bsmoke\b.*\]'
 # This is still serial because neutron doesn't work with parallel. See:
 # https://bugs.launchpad.net/tempest/+bug/1216076 so the neutron smoke
 # job would fail if we moved it to parallel.
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --serial --regex '\[.*\bsmoke\b.*\]' {posargs}
+    tempest run --serial --regex {[testenv:smoke-serial]regex} {posargs}
 
 [testenv:slow-serial]
 envdir = .tox/tempest
@@ -267,10 +283,11 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '\[.*\bslow\b.*\]'
 # The regex below is used to select the slow tagged tests to run serially:
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --serial --regex '\[.*\bslow\b.*\]' {posargs}
+    tempest run --serial --regex {[testenv:slow-serial]regex} {posargs}
 
 [testenv:ipv6-only]
 envdir = .tox/tempest
@@ -278,12 +295,13 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '\[.*\bsmoke|ipv6|test_network_v6\b.*\]'
 # Run only smoke and ipv6 tests. This env is used to tests
 # the ipv6 deployments and basic tests run fine so that we can
 # verify that services listen on IPv6 address.
 commands =
     find . -type f -name "*.pyc" -delete
-    tempest run --regex '\[.*\bsmoke|ipv6|test_network_v6\b.*\]' {posargs}
+    tempest run --regex {[testenv:ipv6-only]regex} {posargs}
 
 [testenv:venv]
 deps =
@@ -442,8 +460,9 @@
 basepython = {[tempestenv]basepython}
 setenv = {[tempestenv]setenv}
 deps = {[tempestenv]deps}
+regex = '\[.*\bsmoke\b.*\]'
 # The below command install stestr master version and run smoke tests
 commands =
     find . -type f -name "*.pyc" -delete
     pip install -U git+https://github.com/mtreinish/stestr
-    tempest run --regex '\[.*\bsmoke\b.*\]' {posargs}
+    tempest run --regex {[testenv:stestr-master]regex} {posargs}