kkc

def get_or_create(session, model, defaults=None, **kwargs):
	"""
	Get or create a model instance while preserving integrity.
	"""
	try:
		return session.query(model).filter_by(**kwargs).one(), False
	except NoResultFound:
		if defaults is not None:
			kwargs.update(defaults)

kkc

[Linux Container Internals 2.0](https://docs.google.com/presentation/d/1S-JqLQ4jatHwEBRUQRiA5WOuCwpTUnxl2d1qRUoTz5g/edit#slide=id.g3e1a17e39e_2_41)

kkc

aws> ec2 describe-vpcs
aws> ec2 create-vpc --cidr-block 10.0.0.0/16
aws> ec2 create-tags --resources vpc-f0bff594 --tags Key=Name,Value=sample-vpc
aws> ec2 describe-vpcs
aws> ec2 describe-internet-gateways
aws> ec2 create-internet-gateway 
aws> ec2 create-tags --resources igw-6992410d --tags Key=Name,Value=sample-vpc-igw
aws> ec2 attach-internet-gateway --vpc-id vpc-f0bff594 --internet-gateway-id igw-6992410d
aws> ec2 describe-internet-gateways
aws> ec2 describe-subnets --query 'Subnets[?VpcId==`vpc-f0bff594`]' 

kkc

ifconfig (or ip link, ip addr) - for obtaining information about network interfaces

ping

for validating, if target host is accessible from my machine. 

ping is also could be used for basic DNS diagnostics - we could ping host by IP-address or by its hostname and then decide if DNS works at all. And then traceroute or tracepath or mtr to look what's going on on the way there.

dig

kkc

You can pull a capture from S3 into #Wireshark using the AWS CLI:
aws s3 cp s3://my-bucket/odd-http.pcap - | wireshark -k -i -

kkc

https://serverfault.com/questions/791715/using-environment-variables-in-kubernetes-deployment-spec

A much easier/cleaner solution: envsubst

In deploy.yml:

LoadbalancerIP: $LBIP
Then just create your env var and run kubectl like this:

export LBIP="1.2.3.4"

kkc

S3 Static Sites

What this will cover

• Host a static website at S3
• Redirect www.website.com to website.com
• Website can be an SPA (requiring all requests to return index.html)
• Free AWS SSL certs
• Deployment with CDN invalidation

Resources

kkc

#!/bin/sh

# Use AWS CLI to get the most recent version of an AMI that 
# matches certain criteria. Has obvious uses. Made possible via
# --query, --output text, and the fact that RFC3339 datetime
# fields are easily sortable.

export AWS_DEFAULT_REGION=us-east-1

aws ec2 describe-images \

kkc

var fs = require('fs');

function Reader() {
    this.content = null;
}

Reader.prototype.getContent = function() {
    if (this.content === null) {
        return new Promise((resolve, reject) => {
            console.log('new promise');

kkc

#!/usr/bin/env python
from applicationinsights import TelemetryClient
import subprocess
import sys
import socket

hostname = socket.gethostname()
telemetry_id = sys.argv[1]

tc = TelemetryClient(telemetry_id)