Make tox.ini tox 4.0 compatible

* use min version 4.2.5, for fixes [1][2][3]
* passenv fixed as space-separated list is not allowed anymore
* dock target uses requirements from requirements.txt as well as
  doc/requirements.txt
* skipsdist is not supported
* whitelist_externals has been removed in favour of allowlist_externals

* reno was added to doc/requirements.txt to fix the releasenotes target
* update setup.cfg to install aodh from tarball in the requirements
  The tarball wasn't being installed when specified in tox.ini, and the
  [extras] section in setup.cfg needed updating to support installing
  from a URL

[1] tox-dev/tox#2754
[2] tox-dev/tox#2824
[3] tox-dev/tox#2828

Change-Id: I4122d0d05f297f864318e80392e6c77fb2e9fdcf

doc/requirements.txt

@@ -4,3 +4,4 @@
 
 sphinx>=2.0.0,!=2.1.0 # BSD
 openstackdocstheme>=2.2.1 # Apache-2.0
+reno>=3.1.0 # Apache-2.0

setup.cfg

@@ -23,7 +23,7 @@ classifier =
 packages =
     aodhclient
 
-[extras]
+[options.extras_require]
 test =
     coverage>=3.6
     oslotest>=1.10.0 # Apache-2.0
@@ -33,6 +33,7 @@ test =
     testtools>=1.4.0
     pifpaf[gnocchi]>=0.23
     gnocchi[postgresql,file]
+    aodh @ https://tarballs.openstack.org/aodh/aodh-master.tar.gz#egg=aodh[mysql]
 
 [entry_points]
 console_scripts =

tox.ini

@@ -1,7 +1,6 @@
 [tox]
-minversion = 3.1.1
+minversion = 4.2.5
 envlist = py38,py39,pep8
-skipsdist = True
 ignore_basepython_conflict = True
 
 [testenv]
@@ -12,12 +11,17 @@ setenv =
    AODH_CLIENT_EXEC_DIR={envdir}/bin
    AODH_ENDPOINT=http://localhost:8042
    GNOCCHI_ENDPOINT=http://localhost:8041
-passenv = GNOCCHI_* AODH_* OS_TEST_TIMEOUT OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_LOG_CAPTURE
+passenv =
+    GNOCCHI_*
+    AODH_*
+    OS_TEST_TIMEOUT
+    OS_STDOUT_CAPTURE
+    OS_STDERR_CAPTURE
+    OS_LOG_CAPTURE
 # NOTE(tonyb): This project has chosen to *NOT* consume upper-constraints.txt
 # NOTE(jd): the -e is on its own line so it is passed a separate argument to pip
 deps =
     .[test]
-    http://tarballs.openstack.org/aodh/aodh-master.tar.gz#egg=aodh[mysql]
 commands = pifpaf run aodh -- stestr run --slowest {posargs}
 
 [testenv:pep8]
@@ -41,14 +45,21 @@ commands =
    coverage report
 
 [testenv:releasenotes]
+deps =
+   -r{toxinidir}/doc/requirements.txt
+   -r{toxinidir}/requirements.txt
+allowlist_externals =
+   sphinx-build
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees --keep-going -b html releasenotes/source releasenotes/build/html
 
 [testenv:docs]
-deps = -r{toxinidir}/doc/requirements.txt
+deps =
+   -r{toxinidir}/doc/requirements.txt
+   -r{toxinidir}/requirements.txt
 commands =
    rm -rf doc/build
    sphinx-build -W --keep-going -b html doc/source doc/build/html
-whitelist_externals = rm
+allowlist_externals = rm
 
 [testenv:debug]
 commands = pifpaf --debug run aodh -- oslo_debug_helper {posargs}