Allow non-default yaml loader and dumper

[coignetp]

What does this PR do?

Allow integrations to use a non-default YAML loader and dumper

How to use it

Inside an integration

import yaml
...

class CustomCheck(AgentCheck):
   ...
   def func(self):
       yaml.load(mystring, Loader=yaml.SafeLoader)

Motivation

Needed for #9815 to use the python safe loader instead of the C one.

Additional Notes

This is changing the behaviour of the undocumented disable_unsafe_yaml agent option (which is true by default).

Before:

• If true, monkey patching, change default loader to CSafeLoader or SafeLoader (same with dumper) and forbid non-default loader/dumper use
• If false, no monkey patch

After:

• If true, monkey patching, change default loader to CSafeLoader or SafeLoader (same with dumper) and print a debug log line if using a different loader/dumper
• If false no monkey patch

[codecov]

Codecov Report

Merging #10032 (7679805) into master (b1eab81) will increase coverage by 0.02%.
The diff coverage is 42.85%.

Flag	Coverage Δ
active_directory	100.00% <ø> (ø)
activemq_xml	82.31% <ø> (ø)
aerospike	86.97% <ø> (+0.36%)	⬆️
airflow	90.00% <ø> (ø)
amazon_msk	87.94% <ø> (ø)
ambari	86.87% <ø> (ø)
apache	95.43% <ø> (ø)
aspdotnet	93.87% <ø> (ø)
avi_vantage	92.07% <ø> (ø)
azure_iot_edge	82.01% <ø> (ø)
cacti	83.95% <ø> (ø)
cassandra_nodetool	94.19% <ø> (ø)
ceph	91.02% <ø> (ø)
cilium	85.84% <ø> (+1.88%)	⬆️
cisco_aci	95.88% <ø> (ø)
clickhouse	96.65% <ø> (ø)
cloud_foundry_api	95.98% <ø> (+0.12%)	⬆️
cockroachdb	97.18% <ø> (ø)
consul	91.74% <ø> (ø)
coredns	96.36% <ø> (ø)
couch	95.19% <ø> (+0.24%)	⬆️
couchbase	81.45% <ø> (ø)
crio	100.00% <ø> (ø)
datadog_checks_base	89.70% <42.85%> (+0.44%)	⬆️
datadog_checks_dev	79.41% <ø> (ø)
datadog_checks_downloader	80.64% <ø> (ø)
datadog_cluster_agent	97.50% <ø> (ø)
directory	94.87% <ø> (ø)
disk	91.15% <ø> (-0.49%)	⬇️
dns_check	94.00% <ø> (ø)
dotnetclr	100.00% <ø> (ø)
druid	97.70% <ø> (ø)
ecs_fargate	77.65% <ø> (ø)
eks_fargate	94.05% <ø> (ø)
elastic	88.54% <ø> (ø)
envoy	93.77% <ø> (+0.25%)	⬆️
etcd	93.09% <ø> (ø)
exchange_server	100.00% <ø> (ø)
external_dns	100.00% <ø> (ø)
fluentd	94.77% <ø> (ø)
gearmand	77.27% <ø> (+1.29%)	⬆️
gitlab	89.94% <ø> (ø)
gitlab_runner	90.32% <ø> (ø)
glusterfs	80.09% <ø> (+0.92%)	⬆️
go_expvar	91.95% <ø> (ø)
gunicorn	93.60% <ø> (ø)
haproxy	95.22% <ø> (+0.17%)	⬆️
harbor	91.58% <ø> (ø)
hazelcast	92.39% <ø> (ø)
hdfs_datanode	90.00% <ø> (ø)
hdfs_namenode	87.94% <ø> (ø)
http_check	90.00% <ø> (+1.81%)	⬆️
ibm_db2	94.79% <ø> (ø)
ibm_mq	89.61% <ø> (-0.18%)	⬇️
ibm_was	97.44% <ø> (ø)
iis	93.01% <ø> (ø)
istio	77.67% <ø> (+0.59%)	⬆️
kafka_consumer	81.87% <ø> (ø)
kong	92.21% <ø> (ø)
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kube_controller_manager	96.85% <ø> (ø)
kube_dns	98.85% <ø> (ø)
kube_metrics_server	100.00% <ø> (ø)
kube_proxy	100.00% <ø> (ø)
kube_scheduler	96.20% <ø> (ø)
kubelet	89.47% <ø> (ø)
kubernetes_state	89.67% <ø> (ø)
kyototycoon	85.96% <ø> (ø)
lighttpd	83.64% <ø> (ø)
linkerd	85.14% <ø> (+1.14%)	⬆️
linux_proc_extras	96.22% <ø> (ø)
mapr	82.62% <ø> (ø)
mapreduce	81.81% <ø> (-0.46%)	⬇️
marathon	83.12% <ø> (ø)
marklogic	95.33% <ø> (ø)
mcache	93.48% <ø> (ø)
mesos_master	90.68% <ø> (ø)
mesos_slave	93.63% <ø> (ø)
mongo	94.74% <ø> (+0.28%)	⬆️
mysql	86.27% <ø> (+0.09%)	⬆️
nagios	89.53% <ø> (ø)
network	77.76% <ø> (+1.00%)	⬆️
nfsstat	95.20% <ø> (ø)
nginx	95.11% <ø> (+0.93%)	⬆️
nginx_ingress_controller	98.30% <ø> (ø)
openldap	96.33% <ø> (ø)
openmetrics	97.14% <ø> (ø)
openstack	51.30% <ø> (ø)
openstack_controller	90.74% <ø> (ø)
oracle	93.65% <ø> (+0.52%)	⬆️
pdh_check	97.77% <ø> (ø)
pgbouncer	90.27% <ø> (ø)
php_fpm	90.04% <ø> (+0.43%)	⬆️
postfix	88.04% <ø> (ø)
powerdns_recursor	95.93% <ø> (ø)
process	85.20% <ø> (+0.28%)	⬆️
prometheus	94.17% <ø> (ø)
proxysql	98.97% <ø> (ø)
rabbitmq	93.74% <ø> (ø)
redisdb	87.28% <ø> (ø)
rethinkdb	97.93% <ø> (ø)
riak	99.22% <ø> (ø)
riakcs	93.61% <ø> (ø)
sap_hana	93.04% <ø> (ø)
scylla	100.00% <ø> (ø)
snowflake	94.28% <ø> (+0.57%)	⬆️
sonarqube	95.69% <ø> (ø)
spark	93.46% <ø> (ø)
sqlserver	82.38% <ø> (ø)
squid	100.00% <ø> (ø)
ssh_check	91.58% <ø> (ø)
statsd	87.36% <ø> (+1.05%)	⬆️
supervisord	92.30% <ø> (ø)
system_core	91.04% <ø> (ø)
system_swap	98.30% <ø> (ø)
tcp_check	88.83% <ø> (ø)
teamcity	80.00% <ø> (ø)
tls	97.04% <ø> (+0.87%)	⬆️
tokumx	58.40% <ø> (?)
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varnish	84.57% <ø> (+0.24%)	⬆️
vault	94.91% <ø> (+0.53%)	⬆️
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vsphere	89.78% <ø> (+0.08%)	⬆️
win32_event_log	86.03% <ø> (+0.28%)	⬆️
windows_service	95.83% <ø> (ø)
wmi_check	92.91% <ø> (ø)
yarn	90.30% <ø> (ø)
zk	84.96% <ø> (+0.75%)	⬆️

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[ofek]

Just need to fix style, and rebase for #10035

[djmitche]

This is fine as-is, or consider the suggestion below.