[FUP Optimisation] redis: added endpoint filtering

[CagriYonca]

Added endpoint filtering for redis instrumentation. We've aligned with Java and NodeJS teams. The customer has three options to filter endpoints:

• Defining ignore-endpoint through the configuration.yaml file of the agent
• Using environment-variable before initialisation
• Using src/instana/configurator.py

If the customer used more than one way of these three, we'd be using one according to this priority:

• Environment variable > in-code setting > agent configuration

Ignoring endpoints through env variable

The customer can use filtering with the environment variable below. If the env variable is set, other two ways will be ignored.

• INSTANA_IGNORE_ENDPOINTS="service:endpoint"
• INSTANA_IGNORE_ENDPOINTS="service:endpoint1,endpoint2"
• Filtering redis instrumentation at all:
  INSTANA_IGNORE_ENDPOINTS="service"
• Filtering multiple instrumentations:
  INSTANA_IGNORE_ENDPOINTS="service1:endpoint1;service2:endpoint1"
INSTANA_IGNORE_ENDPOINTS="service1;service2"

Ignoring endpoints through the configurator.py file

The customer can add a configuration line like below:

• config["tracing"]["ignore_endpoints"] = {"service1": ["endpoint1", "endpoint2"], "service2": []}

Ignoring endpoints through the agent configuration

The customer can add a configuration to agent-folder/etc/instana/configuration.yaml

com.instana.tracing:
  ignore-endpoints:
    service1:    # Add package name, e.g., redis, dynamodb
      - 'endpoint1' # Add endpoint
      - 'endpoint2'
    service2:
      - 'endpoint1'

Reference: https://github.ibm.com/instana/technical-documentation/tree/master/tracing/specification#ignoring-endpoints

[pvital]

Few change requests.

[pvital]

Please convert all message strings to an f-string message for this file.

[pvital]

You can move the if not params: block out of the try-except block and improve it. BTW, if you expect an empty (null or None) params, the type annotation must be params: Optional[Union[Dict[str, Any], str]] = None

Suggested change

	try:
	ignore_endpoints = []
	# If set from env variable (string format)
	if isinstance(params, str):
	if not params:
	return ignore_endpoints
	ignore_endpoints = []
	if not params:
	return ignore_endpoints
	try:
	# If set from env variable (string format)
	if isinstance(params, str):
	...
	except Exception as e:
	print(f"Error parsing ignored endpoints: {str(e)}")
	return ignore_endpoints

[pvital]

This is a bit confusing because the same variable name is used in different context blocks. You can move these lines to the else block and change the variable name to service instead.

[pvital]

Suggested change

	if ":" in pair:
	if pair.contains(":"):

[pvital]

Better change the instrumentation variable name to service.

Suggested change

	instrumentation, endpoints = pair.split(":", 1)
	service, endpoints = pair.split(":", 1)

[pvital]

Let's practice the Clean Code here. It would be better to split this whole function in two: one to parse string ignored endpoints and another to parse dictionary ignored endpoints.

[pvital]

Let's prevent the load and import of all these classes. Move this if block out of the try-except block and all the imports (between lines 8 and 10) to below the import redis.

[pvital]

Suggested change

	if "tracing" in config:
	if "ignore_endpoints" in config["tracing"]:
	if "tracing" in config and "ignore_endpoints" in config["tracing"]:

[pvital]

A better name for this method is is_service_or_endpoint_ignored; the variable names must be coherent.

Suggested change

	def check_if_ignored(
	instrumentation: str,
	command: str,
	) -> bool:
	"""Check if the given instrumentation and command combination should be ignored."""
	return (
	instrumentation in agent.options.ignore_endpoints
	or f"{instrumentation}.{command.lower()}" in agent.options.ignore_endpoints
	)
	def is_service_or_endpoint_ignored(
	service: str,
	endpoint: str,
	) -> bool:
	"""Check if the given service and endpoint combination should be ignored."""
	return (
	service in agent.options.ignore_endpoints
	or f"{service}.{endpoint.lower()}" in agent.options.ignore_endpoints
	)