Test on Python 3.9.

.azure-pipelines/templates/jobs/extended-tests-jobs.yml

@@ -14,6 +14,9 @@ jobs:
         linux-py37:
           PYTHON_VERSION: 3.7
           TOXENV: py37
+        linux-py38:
+          PYTHON_VERSION: 3.8
+          TOXENV: py38
         linux-py37-nopin:
           PYTHON_VERSION: 3.7
           TOXENV: py37
@@ -62,6 +65,14 @@ jobs:
           PYTHON_VERSION: 3.8
           TOXENV: integration
           ACME_SERVER: boulder-v2
+        linux-boulder-v1-py39-integration:
+          PYTHON_VERSION: 3.9
+          TOXENV: integration
+          ACME_SERVER: boulder-v1
+        linux-boulder-v2-py39-integration:
+          PYTHON_VERSION: 3.9
+          TOXENV: integration
+          ACME_SERVER: boulder-v2
         nginx-compat:
           TOXENV: nginx_compat
         linux-integration-rfc2136:

.azure-pipelines/templates/jobs/standard-tests-jobs.yml

@@ -38,10 +38,10 @@ jobs:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.6
           TOXENV: py36
-        linux-py38-cover:
+        linux-py39-cover:
           IMAGE_NAME: ubuntu-18.04
-          PYTHON_VERSION: 3.8
-          TOXENV: py38-cover
+          PYTHON_VERSION: 3.9
+          TOXENV: py39-cover
         linux-py37-lint:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.7

tox.ini

@@ -221,6 +221,9 @@ whitelist_externals =
 passenv = DOCKER_*
 
 [testenv:integration]
+# If any new settings other than commands or passenv are set below, they need
+# to propagated to the testenv py39-integration until
+# https://github.com/certbot/certbot/issues/8384 is fixed.
 commands =
     {[base]pip_install} acme certbot certbot-nginx certbot-ci
     pytest certbot-ci/certbot_integration_tests \
@@ -231,6 +234,13 @@ commands =
     coverage report --include 'certbot-nginx/*' --show-missing --fail-under=74
 passenv = DOCKER_*
 
+[testenv:py39-integration]
+# This tox environment just exists to put py39 in the environment name which
+# earlier in the file we configured to boostrap pip, setuptools, and wheel
+# differently.
+commands = {[testenv:integration]commands}
+passenv = {[testenv:integration]passenv}
+
 [testenv:integration-certbot]
 commands =
     {[base]pip_install} acme certbot certbot-ci