BUG: mismatch `sasl.mechanisms` in cached_schema_registry_client.py

[andharris]

Description

When basic.auth.credentials.source is set to SASL_INHERIT, then sasl.mechanisms (plural) is passed to the schema registry conf, however when configuring the auth in CachedSchemaRegistryClient, then sasl.mechanism (singular) is popped. This causes the check at the end of CachedSchemaRegistryClient.__init__ to raise a ValueError .

How to reproduce

from confluent_kafka.avro import AvroProducer

config = {
    'schema.registry.url': 'http://test.com:9091',
    'schema.registry.basic.auth.credentials.source': 'SASL_INHERIT',
}

AvroProducer(config)

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-7-88b3fcdf0322> in <module>
      6 }
      7 
----> 8 AvroProducer(config)

/usr/local/lib/python3.7/site-packages/confluent_kafka/avro/__init__.py in __init__(self, config, default_key_schema, default_value_schema, schema_registry)
     42 
     43         if schema_registry is None:
---> 44             schema_registry = CachedSchemaRegistryClient(sr_conf)
     45         elif sr_conf.get("url", None) is not None:
     46             raise ValueError("Cannot pass schema_registry along with schema.registry.url config")

/usr/local/lib/python3.7/site-packages/confluent_kafka/avro/cached_schema_registry_client.py in __init__(self, url, max_schemas_per_subject, ca_location, cert_location, key_location)
    114 
    115         if len(conf) > 0:
--> 116             raise ValueError("Unrecognized configuration properties: {}".format(conf.keys()))
    117 
    118     def __del__(self):

ValueError: Unrecognized configuration properties: dict_keys(['sasl.mechanisms'])

Checklist

Please provide the following information:

• confluent-kafka-python and librdkafka version (confluent_kafka.version() and confluent_kafka.libversion()): ('1.2.0', 16908288)
• Apache Kafka broker version: na
• Client configuration: {...} see reproducible example
• Operating system: macOS
• Provide client logs (with 'debug': '..' as necessary) na
• Provide broker log excerpts na
• Critical issue: bug

[andharris]

Looks like #733 will fix this up once merged.

[rnpridgeon]

Merged