Articles by Peter Sabaini

  1. NATS and Go

    Overview

    These are some notes and an example on hooking up Golang programs to the NATS messaging system

    NATS Messaging

    NATS messaging enables data sharing via a publish/subscribe mechanism across different processes, systems and platforms. NATS core offers an "at most once" quality of service. If a subscriber is …

  2. Fabric Automation

    Occasionally I have to do scripting work outside of our config management tool of choice, Juju 1 - eg. for bootstrapping or one-off jobs. I had used Fabric version 1 previously (as well as Plumbum) for those, and was looking at Fabric 2 (respectively it's sidekick Invoke) now.

    So whats Fabric …

  3. Thespian, A Python Actor System

    Overview: Concurrency with Actors

    Actor systems model concurrency with actors. In such a system, actors are independent objects that communicate asynchronously with each other via message passing.

    An actor can:

    • Receive and send messages asynchronously

    • Change private state

    • Create new actors

    Each actor has an address under which it can …

  4. Requests debugging

    TIL that the Python requests library is able to dump request/response details to the debug log - quite useful for development and debugging of http clients.

    Switch it on with something like this:

    import requests
    import logging
    try: # for Python 3
        from http.client import HTTPConnection
    except ImportError:
        from httplib …
  5. Neutronic Security

    Or: digging into Openstack Neutrons' packet filtering bowels

    The other day I had to track down weird behaviour with Neutron security groups in one of our clouds, and thought to share notes on debugging those and on Neutron networking in general 1.

    Compute node neutronics

    Recall that on a compute …

  6. Ceph Cheatsheet

    I love Ceph to pieces! I don't love it's docs that much though, and I find the multi-level subcommands unintuitive at times. Quick, is it "ceph pg query x.y" or "ceph pg x.y query"? There's some good docs out there, but to me they feel scattered and it's …