rule_tree error handling is missing a logger has a not helpful error message

[dtrai2]

It is possible run into an exception when a rule_tree is wrongly configured.

Expected behavior
Logprep compains already on startup that the rule_tree_config is not correct, and the rule_tree should have a logger in case other unforeseen errors happen.

Current behavior
In an older logprep version one could see following logline, if the rule was not configured as a separate file, but defined directly inside the pipeline.yaml

RuleTree   WARNING : Error parsing rule "None.yml": TypeError: '<' not supported between instances of 'int' and 'str'. Ignore and continue with next rule.

This is not very helpful as it is not easily recognizable which rule or rule_tree is producing this error. In the current main branch though this doesn't even happen anymore as the rule_tree doesn't have a logger resulting in:

[...]
  File "[...]/logprep/framework/rule_tree/rule_tree.py", line 125, in add_rule
    logger.warning(
    ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'warning'

Steps to reproduce
Create the following pipeline.yml:

input:
    dummy:
        type: dummy_input
        documents: []
output:
    dummy:
        type: dummy_output
pipeline:
    - grokker:
        type: grokker
        specific_rules:
          - filter: 'tags: "foo bar" AND message: bi'
            grokker:
                mapping:
                    message: "%{GREEDYDATA:foo}"
        generic_rules: []
        tree_config: tconfig.json

Create the following tree_config named tconfig.json (as referenced inside the pipeline.yml):

{
  "priority_dict": {
    "tag": 1,
    "message": 2
  },
  "tag_map": {
    "field_name_to_check_for_in_rule": "TAG-TO-CHECK-IF-IN-EVENT"
  }
}

Notice that the priority_dict uses integer values instead of string values.

Run logprep with:

logprep run pipeline.yml

Environment

Logprep version: 856ceaf
Python version: 3.11.0

Possible solution

• Implement the tree config as attrs class, with well defined expected types, and load them on logprep start up.
• Add a logger to the rule_tree