ume-logging

Uniform JSON logging for University Medicine Essen applications.

A consistent logging standard across multiple languages, designed for microservices running in Docker/Kubernetes with ELK stack integration.

Implementations

Language	Package	Status
Python	ume-logging	✅ Available
Scala	—	🚧 Planned
Rust	—	🚧 Planned

Why?

When running microservices written in different languages, you need consistent log output for:

• Centralized logging — Parse logs uniformly in ELK/Loki/CloudWatch
• Request tracing — Correlate logs across services with request_id
• Debugging — Know which app/service/environment produced each log
• Compliance — Automatic PII scrubbing and user ID hashing

Standard Log Format

All implementations produce JSON logs with this structure:

{
  "time": "2025-01-15T10:30:00.000Z",
  "level": "INFO",
  "logger": "my.module",
  "message": "Processing complete",
  "org": "UME",
  "app": "patient-api",
  "env": "prod",
  "service": "fhir-import",
  "component": "parser",
  "request_id": "550e8400-e29b-41d4-a716-446655440000",
  "user": {
    "hash": "a1b2c3d4e5f6..."
  },
  "trace_id": "0af7651916cd43dd8448eb211c80319c",
  "span_id": "b7ad6b7169203331"
}

Common Features

All implementations provide:

Feature	Description
JSON output	Single-line JSON to stdout
Context fields	app, env, service, component in every log
Request ID	X-Request-ID header propagation
User hashing	SHA256 hash of user identifiers
PII scrubbing	Redact emails and phone numbers
OpenTelemetry	Inject trace_id and span_id when available

Environment Variables

Standard across all implementations:

Variable	Description	Default
UME_LOG_LEVEL	Logging level	INFO
UME_APP	Application name	—
UME_ENV	Environment	prod
UME_SERVICE	Service name	—
UME_COMPONENT	Component name	—
UME_USER_HASH_SALT	Salt for user ID hashing	ume

Getting Started

Python

pip install ume-logging

import logging
from umelogging import log_configure

log_configure("INFO", app="my-app", env="prod")
logging.getLogger(__name__).info("Hello from Python")

See python/README.md for full documentation.

License

MIT License — Copyright © University Medicine Essen