Structured Logging

Centralised Structured Logging

import structlog, uuid

structlog.configure(processors=[
    structlog.processors.add_log_level,
    structlog.processors.TimeStamper(fmt="iso"),
    structlog.processors.JSONRenderer()
])
log = structlog.get_logger()

@app.middleware("http")
async def log_middleware(request, call_next):
    request_id = str(uuid.uuid4())
    with structlog.contextvars.bind_contextvars(
        request_id=request_id,
        service="user-service"
    ):
        response = await call_next(request)
        log.info("request_done", status=response.status_code)
        return response

# Output: {"event":"request_done","service":"user-service",
#          "request_id":"abc","status":200,"timestamp":"..."}

# Aggregation: Filebeat->Elasticsearch->Kibana
#          or: Fluentd->Loki->Grafana