jaymecd

Based on this blogpost.

To sign Git commits, you need a gpg key. GPG stands for GNU Privacy Guard and is the de facto implementation of the OpenPGP message format. PGP stands for ‘Pretty Good Privacy’ and is a standard to sign and encrypt messages.

Setting up

Install with Homebrew:

$ brew install gpg

jaymecd

GNU Make Cheatsheet

Based on https://www.gnu.org/software/make/manual/html_node/Quick-Reference.html

Directives

Directive	Description
define variable define variable = define variable := define variable ::= define variable += define variable ?= endef	Define multi-line variables.
undefine variable	Undefining variables.

jaymecd

How do I round to 2 decimals?

In python, you have floats and decimals that can be rounded. If you care about the accuracy of rounding, use decimal type. If you use floats, you will have issues with accuracy.

All the examples use demical types, except for the original value, which is automatically casted as a float.

To set the context of what we are working with, let's start with an original value.

Original Value

jaymecd

package main

import (
	"context"
	"errors"
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"

jaymecd

NOTE: This is a question I found on StackOverflow which I’ve archived here, because the answer is so effing phenomenal.

---

Q: How can I make a chain of function decorators in Python?

---

If you are not into long explanations, see [Paolo Bergantino’s answer][2].

jaymecd

Introduction

When applications are running in production, they become black boxes that need to be traced and monitored. One of the simplest, yet main, ways to do so is logging. Logging allows us - at the time we develop our software - to instruct the program to emit information while the system is running that will be useful for us and our sysadmins.

jaymecd

# This is a short collection of tools that are useful for managing your
# known_hosts file. In this case, I'm using the '-f' flag to specify the
# global known_hosts file because I'll be adding many deploy users on this
# system. Simply omit the -f flag to operate on ~/.ssh/known_hosts

# Add entry for host
ssh-keyscan -H github.com > /etc/ssh/ssh_known_hosts

# Scan known hosts
ssh-keygen -f /etc/ssh/ssh_known_hosts -H -F github.com

jaymecd

'Update or create a stack given a name and template + params'
from __future__ import division, print_function, unicode_literals

from datetime import datetime
import logging
import json
import sys

import boto3
import botocore

jaymecd

package main
import (
    "net/http"
)

func redirect(w http.ResponseWriter, req *http.Request) {
    http.Redirect(w, req,
            "https://" + req.Host + req.URL.String(),
            http.StatusMovedPermanently)
}

jaymecd

#cloud-config
write_files:
    - content: |
        #!/bin/bash
        REGION=$( curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | python -c "import sys, json; print json.load(sys.stdin)['region']" )
        aws --region $REGION ssm list-associations --max-items 1 > /dev/null 2>&1
        if [ $? -ne 0 ]; then
          echo "No privs to run Amazon SSM agent. Stopping..."
          sudo stop amazon-ssm-agent
        fi