Add certbot-dns-rfc2136 integration testing (#8448)

* tests: add certbot-dns-rfc2136 integration tests

* dont use 'with' form of socket.socket

fixes py2 crash

* address some feedback:

- conftest: make DNS server a global resource
- conftest: add dns_xdist parameter into node config
- conftest: add --dns-server=bind flag
- conftest: if configured, point the ACME server to the DNS server
- dnsserver: make it sort-of compatible with xdist (future-proofing)
- context: parameterize dns-rfc2136 credentials file (future proofing)
- context: reduce dns-rfc2136 propagation time to speed up tests
- tox: add a integration-dns-rfc2136 target
- rfc2136: add a test/zone for subdelegation
- rfc2136: skip tests if no DNS server is configured

* try add integration-dns-rfc2136 to CI

* mock recursive dns via RPZ

* update --dns-server args and tox.ini args

* address more feedback:

- dns_server: rename rfc2136 creds file to .tpl
- dns_server: dont vary dns server port, instead we will vary zone names (#8455)
- dns_server: log error if bind9 fails to stop cleanly
- dns_server: replace assert with raise
- context: remove redundant _worker_id
- context: remove redundant cleanup override
- context: fix seek/flush in credentials context manager
- context: rename skip_if_no_server -> ...bind_server
- context: add newline EOF

* conftest: document _setup_primary_node sideeffects

* ci: rfc2136-integration from standard->nightly

* fix _stop_bind (function was renamed to stop)

* ignore errors from shutil.rmtree during cleanup

* dns_server: check for crash while polling

* remove --dry-run from rfc2136 test

1 files changed, 7 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 5dcc55d3f..7f806bb4d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -240,6 +240,13 @@ commands =
         --cov-config=certbot-ci/certbot_integration_tests/.coveragerc
     coverage report --include 'certbot/*' --show-missing --fail-under=62
 
+[testenv:integration-dns-rfc2136]
+commands =
+    {[base]pip_install} acme certbot certbot-dns-rfc2136 certbot-ci
+    pytest certbot-ci/certbot_integration_tests/rfc2136_tests \
+        --acme-server=pebble --dns-server=bind \
+        --numprocesses=1
+
 [testenv:integration-external]
 # Run integration tests with Certbot outside of tox's virtual environment.
 commands =