nameko-prometheus

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tests
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nameko-prometheus is a dependency for the nameko microservice framework which allows application metrics collection with Prometheus.

Features

automatic collection of request latency metrics for RPC methods, event handlers and HTTP requests

custom application metrics are also exposed automatically

HTTP endpoint exposing metrics to be scraped by Prometheus

Installation

pip install nameko-prometheus

You can also install the in-development version with:

pip install https://github.com/emplocity/nameko-prometheus/archive/master.zip

Usage

Define your application metrics using types from prometheus_client, such as Counter, Gauge, Histogram, etc. Add a PrometheusMetrics dependency provider to your service class. Then add a HTTP entrypoint (usually routed under /metrics URL) that forwards the request to expose_metrics() method of the provider. That's it!

from nameko.rpc import rpc
from nameko.web.handlers import http
from nameko_prometheus import PrometheusMetrics
from prometheus_client import Counter


work_units = Counter(
    "my_service_work_units_total", "Total number of work units", ["work_type"]
)


class MyService:
   metrics = PrometheusMetrics()

   @rpc
   def say_hello(self):
      work_units.labels(work_type="hard").inc()
      return "Hello!"

   @http("GET", "/metrics")
   def serve_metrics(self, request):
      return self.metrics.expose_metrics(request)

There are a few automatically defined metrics as well. See the documentation of PrometheusMetrics for more.

See also the full stack example in example/ directory in this repo.

Documentation

https://nameko-prometheus.readthedocs.io/

Development

To run the all tests run:

tox

Note, to combine the coverage data from all the tox environments run:

Windows	set PYTEST_ADDOPTS=--cov-append tox
Other	PYTEST_ADDOPTS=--cov-append tox

Development roadmap

Things we'd like to have in the future:

automatic registration of /metrics HTTP endpoint

decorator to exclude specific methods from tracing

Authors

nameko-prometheus is developed and maintained by Emplocity.

License

This work is released under the Apache 2.0 license.

Emplocity/nameko-prometheus