Viewing scales metrics from Pyramid

We’ve recently started experimenting with the excellent scales library to collect in-process metrics (see Coda Hale’s CodeConf talk “Metrics everywhere” among many others for reasons why one definitely wants to do that).

Scales comes with a flask-based HTTP server that allows viewing the collected measurements and dumping them as JSON. But if you already are in a web application, there’s no real need to spin up yet another thread, open another port etc. to do this. In our case, we’re using Pyramid, so here’s a quick recipe to get the same view that greplin.scales.flaskhandler provides:

Update 2013-11-06: This code is now released as pyramid_scales.

# in your Pyramid setup
config.add_route('scales', '/scales/*prefix')

from StringIO import StringIO
from pyramid.view import view_config
import greplin.scales
import greplin.scales.formats

@view_config(route_name='scales', renderer='string')
def scales_stats(request):
    parts = request.matchdict.get('prefix')
    path = '/'.join(parts)
    stats = greplin.scales.util.lookup(greplin.scales.getStats(), parts)

    output = StringIO()
    outputFormat = request.params.get('format', 'html')
    query = request.params.get('query', None)
    if outputFormat == 'json':
        request.response.content_type = 'application/json'
        greplin.scales.formats.jsonFormat(output, stats, query)
    elif outputFormat == 'prettyjson':
        request.response.content_type = 'application/json'
        greplin.scales.formats.jsonFormat(output, stats, query, pretty=True)
        request.response.content_type = 'text/html'
        # XXX Dear pyramid.renderers.string_renderer_factory,
        # you can't be serious
        request.response.default_content_type = 'not-text/html'
        greplin.scales.formats.htmlHeader(output, '/' + path, __name__, query)
        greplin.scales.formats.htmlFormat(output, tuple(parts), stats, query)

    return output.getvalue()

August, 15th–17th: Sprinting on Pyramid

After Zope “-the-Framework” reaching the end of its lifecycle during the last few years, we did a bunch of new projects with Pyramid, a nice web framework primarily authored by long-term Zope developer Chris McDonough.

We think it’s about time to give something back to the community, and become more involved in Pyramid development. We therefore happily announce to host a large Pyramid sprint organised in cooperation with the team. You find more information and sprint topics at GitHub.

The sprint starts on Thu, August 15th 10:00h CEST, and ends on Sat, August 17th with a garden party in the evening! Expect BBQ, beer and (most likely) live music!

If you would like to attend, please sign up on lanyrd.