PYTHON-2793 Stop testing TLS with Python 3.10 and MongoDB <= 3.4 (#748)

Author: ShaneHarvey

.evergreen/config.yml

@@ -2533,6 +2533,31 @@ buildvariants:
     auth-ssl: "*"
   display_name: "${platform} ${python-version-windows} ${auth-ssl}"
   tasks: *all-server-versions
+  rules:
+    # Python 3.10+ and MongoDB <= 3.4 don't have any TLS ciphers in common.
+    - if:
+        platform: "*"
+        python-version-windows: "3.10"
+        auth-ssl: "auth-ssl"
+      then:
+        remove_tasks:
+          - ".2.6"
+          - ".3.0"
+          - ".3.2"
+          - ".3.4"
+
+- matrix_name: "tests-windows-python-version-3.10"
+  matrix_spec:
+    platform: windows-64-vsMulti-small
+    python-version-windows: ["3.10"]
+    auth: "auth"
+    ssl: "nossl"
+  display_name: "${platform} ${python-version-windows} ${auth} ${ssl}"
+  tasks:
+    - ".2.6"
+    - ".3.0"
+    - ".3.2"
+    - ".3.4"
 
 - matrix_name: "tests-windows-python-version-32-bit"
   matrix_spec:
@@ -2541,6 +2566,31 @@ buildvariants:
     auth-ssl: "*"
   display_name: "${platform} ${python-version-windows-32} ${auth-ssl}"
   tasks: *all-server-versions
+  rules:
+    # Python 3.10+ and MongoDB <= 3.4 don't have any TLS ciphers in common.
+    - if:
+        platform: "*"
+        python-version-windows-32: "3.10"
+        auth-ssl: "auth-ssl"
+      then:
+        remove_tasks:
+          - ".2.6"
+          - ".3.0"
+          - ".3.2"
+          - ".3.4"
+
+- matrix_name: "tests-windows-python-version-3.10"
+  matrix_spec:
+    platform: windows-64-vsMulti-small
+    python-version-windows-32: ["3.10"]
+    auth: "auth"
+    ssl: "nossl"
+  display_name: "${platform} ${python-version-windows-32} ${auth} ${ssl}"
+  tasks:
+    - ".2.6"
+    - ".3.0"
+    - ".3.2"
+    - ".3.4"
 
 - matrix_name: "tests-python-version-supports-openssl-110-test-ssl"
   matrix_spec:
@@ -2564,6 +2614,16 @@ buildvariants:
     encryption: "*"
   display_name: "Encryption ${platform} ${python-version-windows} ${auth-ssl}"
   tasks: *encryption-server-versions
+  rules:
+    # Python 3.10+ and MongoDB <= 3.4 don't have any TLS ciphers in common.
+    - if:
+        platform: "*"
+        python-version-windows: "3.10"
+        auth-ssl: "auth-ssl"
+        encryption: "*"
+      then:
+        remove_tasks:
+          - ".2.6"
 
 # Storage engine tests on Amazon1 (x86_64) with Python 2.7.
 - matrix_name: "tests-storage-engines"

doc/examples/tls.rst

@@ -249,3 +249,19 @@ revocation checking failed::
   [('SSL routines', 'tls_process_initial_server_flight', 'invalid status response')]
 
 See :ref:`OCSP` for more details.
+
+Python 3.10+ is incompatible with TLS/SSL on MongoDB <= 3.4
+...........................................................
+
+Note that Python 3.10+ is incompatible with TLS/SSL on MongoDB <= 3.4. The
+following are some example errors that may occur with this combination::
+
+  SSL handshake failed: localhost:27017: [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure (_ssl.c:997)
+  SSL handshake failed: localhost:27017: EOF occurred in violation of protocol (_ssl.c:997)
+
+The MongoDB server logs will show the following error::
+
+  2021-06-30T21:22:44.917+0100 E NETWORK  [conn16] SSL: error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher
+
+To resolve this issue, use Python <=3.10, upgrade to MongoDB 3.6+, or install
+pymongo with the :ref:`OCSP` extra which relies on PyOpenSSL.