[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]

Well done, @CagriYonca, but I still have some comments.

[pvital]

Few more request changes.

As discussed in our call, let's change the approach and filter the spans before sending them to the Agent (or Collector) - see src/instana/agent/host.py:300. That way, we can have a one-size-fits-all solution, and no changes to the instrumentation code will be necessary.

[pvital]

Few requests.

[pvital]

It looks good to me.