WRP Validator Integration

[denopink]

Overview

• Introduced in v0.9.6, we're currently on v0.10.7
• Validators are disabled by default
• Scytale's code interprets configured validator failures as something to either
  • log a info/warning message and continue with the request or
  • log an error and return a 400
• Only cd has validator enabled machines (i.e. scytale)

Available validators:

• always_invalid
  • doesn't validate anything about the message and always returns an error
• always_valid
  • doesn't validate anything about the message and always returns nil
• utf8
  • validates that it contains UTF-8 strings
• msg_type
  • validates the message's Type
• source
  • validates the message's Source
• destination
  • validates the message's Destination
• simple_res_req
  • validates the message's Type is of SimpleRequestResponseMessageType
• simple_event
  • validates the message's Type is of SimpleEventMessageType
• spans
  • validates the message's Spans
    • `An array of arrays of timing values as a list in the format: "parent" (string), "name" (string), "start time" (int), "duration" (int), "status" (int)

Integration Details

Integration Details

WRP validators are configured with the following (regardless of the application code) yaml:

# wrpValidators defines the wrp validators used to validate incoming wrp messages.
# (Optional)
# Available validator types: always_invalid, always_valid, utf8, msg_type, source, destination, simple_res_req, simple_event, spans
# Available validator levels: info, warning, error
# Validators can be disabled with `disable: true`, it is false by default
wrpValidators:
  - type: utf8
    level: warning
    disable: true
  - type: source
    level: error

Key points:

• no validator is included by default
• a level is assigned to a given validator (default value is unknown and it's consider invalid): info, warning, error
• during a validation failure, the application code determines how the validator level is interpret

Currently, only cd has validator enabled scytales . This is the validator config:

wrpValidators:
  - type: utf8
    level: error
  - type: msg_type
    level: error
  - type: destination
    level: warning
  - type: source
    level: warning

• utf8 and msg_type validation errors are logged as errors and scytale returns a 400
• destination and source validation errors are logged as warnings (scytale continues with the request)

Pending Questions

1. For destination do want to allow destinations without dns: identifiers to go through?
2. Which validators should scytale use?
3. For the selected validators, what level should be used?