Andrew Odewahn odewahn

I really liked @tjvantoll article Handling Failed HTTP Responses With fetch(). The one thing I found annoying with it, though, is that response.statusText always returns the generic error message associated with the error code. Most APIs, however, will generally return some kind of useful, more human friendly message in the body.

Here's a modification that will capture this message. The key is that rather than throwing an error, you just throw the response and then process it in the catch block to extract the message in the body:

fetch("/api/foo")
  .then( response => {
    if (!response.ok) { throw response }
    return response.json()  //we only get here if there is no error
 })

I was trying to pass config variables from a backend written in Go to a single page app (SPA) written in react. For example, I wanted to set an "Env" flag to dev or prod or control whether you have to log in or not. Here's an example of the /api/config route that supplies this data:

{
    "Auth0ClientDomain": "odewahn.auth0.com", 
    "Auth0ClientID": "gcSxq9GfpUdVWNIvYiOsP7rh1s8u6ftA", 
    "ClientBrowser": "HTTPie", 
    "ClientOS": "darwin", 
    "Env": "dev", 
 "FirstClientLoad": "true",

How do we make it easy (well, easier) for users to run pre-built Docker containers?

Binder

Launchbot

Desktop GUI for publishing and running containers.

Install this:

https://github.com/rackerlabs/carina/releases

Copy it to a directory on your path and make it executable

$ mv carina-darwin-amd64 /usr/local/bin/carina

Network Notes

Set up a Docker of Vagrant-based lab where you set up your own network and topologies to learn, with a final case study on setting up a secure (!) VPC on AWS.

tcp/ip on Linux

IP addresses
sub-nets and CIDR
IPv6
Ports

	package main

	import (
	"fmt"
	"log"

	"github.com/samalba/dockerclient"
	)

	// Helpful:

	package main

	import (
	"crypto/rand"
	"fmt"
	"log"

	"github.com/fsouza/go-dockerclient"
	)

	package main

	import (
	"fmt"
	"os/exec"
	"strings"
	)

	func runCmd(cmdArgs []string) ([]string, error) {
	cmdName := "docker-machine"

	export TOKEN=$( head -c 30 /dev/urandom \| xxd -p )
	export POOL_SIZE=5
	export OVERPROVISION_FACTOR=2
	export CPU_SHARES=$(( (1024*${OVERPROVISION_FACTOR})/${POOL_SIZE} ))
	export TMPNB_NODE=6df651e0-4701-411d-b11c-3cbfe73b86d7-n1
	export DOCKER_HOST=tcp://104.130.0.38:2376

	docker run -d \
	-P \
	-h spark.tmpnb-oreilly.com \

	export TOKEN=$( head -c 30 /dev/urandom \| xxd -p )
	export POOL_SIZE=5
	export OVERPROVISION_FACTOR=2
	export CPU_SHARES=$(( (1024*${OVERPROVISION_FACTOR})/${POOL_SIZE} ))
	export TMPNB_NODE=bb0f0ccc-2dcb-410b-94cf-808c99324ab6-n1
	export DOCKER_HOST=tcp://104.130.0.25:2376

	docker run -d \
	-P \
	-p 80 \