Error logging on: Contact registrant: Domain registry contact error

[mmeest]

Regarding issue #439

Add structured JSON error logging for Contact registrant Registry API failures

This PR introduces structured, machine-readable error logging for the Contact registrant flow when communication with the Registry API fails. Logging is implemented in registry_connector.rb following EIS logging standards (NDJSON, timestamped, with consistent keys and sanitized details).

Three types of errors are now handled:

• Registry API CommunicationError – non-success HTTP response from the Registry API (e.g., 4xx/5xx).
• Registry API NetworkError – networking issues such as timeout, connection refused, DNS errors.
• Registry API UnexpectedError – unexpected runtime exceptions (e.g., JSON parsing errors, other exceptions).

Example structured log outputs (JSON)

CommunicationError:

{
  "timestamp": "2025-09-25T12:34:56.789Z",
  "level": "error",
  "message": "Registry API communication error",
  "event": "registry.api.communication_error",
  "service": "rest-whois",
  "environment": "prod",
  "host": "server01.example.com",
  "pid": 12345,
  "error": {
    "type": "CommunicationError",
    "message": "HTTP 500"
  },
  "details": {
    "url": "https://registry.example/api/v1/contact_requests",
    "request_method": "POST",
    "request_uri": "/api/v1/contact_requests",
    "response_body": "{\"error\":\"Internal server error\"}"
  },
  "schema_version": "1.0.0",
  "log_version": "1.0.0"
}

NetworkError:

{
  "timestamp": "2025-09-25T12:35:01.123Z",
  "level": "error",
  "message": "Registry API network connection failed",
  "event": "registry.api.network_error",
  "service": "rest-whois",
  "environment": "prod",
  "host": "server01.example.com",
  "pid": 12345,
  "error": {
    "type": "Net::OpenTimeout",
    "message": "execution expired"
  },
  "details": {
    "url": "https://registry.example/api/v1/contact_requests",
    "request_method": "POST",
    "request_uri": "/api/v1/contact_requests"
  },
  "schema_version": "1.0.0",
  "log_version": "1.0.0"
}

UnexpectedError:

{
  "timestamp": "2025-09-25T12:35:10.456Z",
  "level": "error",
  "message": "Registry API unexpected error",
  "event": "registry.api.unexpected_error",
  "service": "rest-whois",
  "environment": "prod",
  "host": "server01.example.com",
  "pid": 12345,
  "error": {
    "type": "JSON::ParserError",
    "message": "765: unexpected token at ''",
    "stack": "app/services/registry_connector.rb:23 | app/controllers/contact_requests_controller.rb:45"
  },
  "details": {
    "url": "https://registry.example/api/v1/contact_requests",
    "request_method": "POST",
    "request_uri": "/api/v1/contact_requests"
  },
  "schema_version": "1.0.0",
  "log_version": "1.0.0"
}

• Logs are structured JSON suitable for machine parsing and NDJSON ingestion.
• Includes timestamp, log level, event, service, host, process id, error object, and request details.
• Avoids logging PII; only necessary request and response info is included.
• Differentiates between network, communication, and unexpected errors for better observability and debugging.

[maricavor]

Could you refactor method perform_request, now it is too big and not DRY. Also maybe add tests for different error scenarios?

[mmeest]

Refactored perform_request method and added tests

[github-actions]

🚀 Deploy Complete!

Property	Value
App	restwhois
Slot	1
URL	https://restwhois1-dev.cloud.tld.ee
Namespace	restwhois1-dev

(Environment ready for testing)