wware

Non-blocking

The System.lang.Runtime.exec() method is non-blocking, so you call it and it spawns a background process.

Unfortunately the java.lang.Process thingy in Java 8 has no way to get a PID, so you need a cheesy hack to find it.

wware

v1 = [0, 2, -1];
v2 = [1, 3, 3];
y = [v2[0] - v1[0], v2[1] - v1[1], v2[2] - v1[2]];
translate(v1)
    rotate(-acos(y[2] / norm(y)), cross(y, [0, 0, 1]))
        cylinder(h=norm(y), d=0.1);

wware

#!/usr/bin/env python
# https://en.wikipedia.org/wiki/Isomorphic_keyboard
# any hexagonal layout is defined by two offsets (the value of the third is forced by the first two)

import sys

many = [20 * [None] for _ in range(20)]

def display():
    width = 4

wware

Messing with Ansible and Docker

Nobody can remember how to use Docker, it is far too confusing. So here are some hints.

sudo docker build -t simple_flask:dockerfile .
sudo docker run -p 5000:5000 simple_flask:dockerfile python hello.py

My actual intention is to learn Ansible. But in order to run Ansible you need Docker, unless you happen to have a rackful of machines at your disposal which I do not.

wware

#!/bin/bash

wait_all() {
    # As soon as one of the background processes creates the EPIC_FAIL file,
    # kill all background processes, rm EPIC_FAIL, and stop looping.
    while [ $(jobs | grep -v Done | wc -l) -ne 0 ]; do
        sleep 1
        if [ -f EPIC_FAIL ]; then
            rm -f EPIC_FAIL
            echo OUCH

wware

#!/usr/bin/env python

import argparse
import logging
import os
import sys
import pprint
from textwrap import dedent

HERE = os.path.dirname(__file__)

wware

#!/usr/bin/env python

import logging
from flask import Flask

from twisted.internet import ssl, reactor
from twisted.web.wsgi import WSGIResource
from twisted.web.server import Site
from twisted.python.threadpool import ThreadPool
from twisted.application import service

wware

Feature toggle decorator

This is a feature toggle scheme for the system I maintain at my job. The goal is to be able to easily toggle functions that have been recently pushed to production, so if things go bad, we have an easy mitigation plan.

Create a database table with three columns, Key (string), Value (boolean), LastChanged (timestamp). The purpose of the LastChanged column is just for record keeping to decide when a feature is deemed trustworthy. The several for a given key string present the history of switching the feature on and off,

wware

import os
import logging
from contextlib import contextmanager

logging.basicConfig(
    format='%(asctime)-15s  %(levelname)s  %(filename)s:%(lineno)d  %(message)s',
    level=logging.INFO
)

def __LINE__():

wware

#!/bin/bash

help() {
    echo "Bash script that parses cmd line args without getopt(s)"
    echo "Adapted from https://stackoverflow.com/questions/192249"
    echo "    -h, --help        print this help message"
    echo "    -f, --foo         set FOO variable"
    echo "    -b, --bar         set BAR variable"
    echo "    -d, --debug       enable debug (doesn't really do anything here)"
    echo "    <anything else>   becomes a positional argument"