Jeff Keen jkeen

How to setup a practically free CDN using Backblaze B2 and Cloudflare

⚠️ Note 2023-01-21
Some things have changed since I originally wrote this in 2016. I have updated a few minor details, and the advice is still broadly the same, but there are some new Cloudflare features you can (and should) take advantage of. In particular, pay attention to Trevor Stevens' comment here from 22 January 2022, and Matt Stenson's useful caching advice. In addition, Backblaze, with whom Cloudflare are a Bandwidth Alliance partner, have published their own guide detailing how to use Cloudflare's Web Workers to cache content from B2 private buckets. That is worth reading,

This assert.asyncThrows custom assertion allows us to write tests against failing async code, usually as a result of a server error (4xx/5xx response).

test('If the index route errors, I see a message', async function(assert) {
  server.create('post');
  server.get('/posts/:id', { errors: ['The site is down'] }, 500); // force Mirage to error

  await assert.asyncThrows(() => {
    return visit('/posts/1');
 }, 'GET /posts/1 returned a 500');

Version: ^0.2.0-beta.5

How can I check the serialized version of a model?

server.get('api/employee's, function(schema, request) {
  employee = schema.employee.find(1);
  this.serializerOrRegistry.serialize(employee, request);

  return foo;
});

Subdomaining Localhost with Rails 5

I've been following this blog post on how to set up an api-only Rails 5 application. One of the sections talks about creating a subdomain for your api

Rails.application.routes.draw do
  constraints subdomain: "api" do
    scope module: "api" do

Get Git log in JSON format

git log --pretty=format:'{%n  "commit": "%H",%n  "abbreviated_commit": "%h",%n  "tree": "%T",%n  "abbreviated_tree": "%t",%n  "parent": "%P",%n  "abbreviated_parent": "%p",%n  "refs": "%D",%n  "encoding": "%e",%n  "subject": "%s",%n  "sanitized_subject_line": "%f",%n  "body": "%b",%n  "commit_notes": "%N",%n  "verification_flag": "%G?",%n  "signer": "%GS",%n  "signer_key": "%GK",%n  "author": {%n    "name": "%aN",%n    "email": "%aE",%n    "date": "%aD"%n  },%n  "commiter": {%n    "name": "%cN",%n    "email": "%cE",%n    "date": "%cD"%n  }%n},'

The only information that aren't fetched are:

%B: raw body (unwrapped subject and body)
%GG: raw verification message from GPG for a signed commit

ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:
ffmpeg -i input.mp3 output.wma

You can get the list of supported formats with:
ffmpeg -formats

You can get the list of installed codecs with:

I had some trouble getting Ember-CLI and Ember-Data working with my existing HTTP API. These are the things I had to do to get it working:

Use `ActiveModelSerializer` by default

My API returns underscored_keys, not camelizedKeys. It's not exactly the standard ActiveModel, but it's quite similar. I started by defining a default (application) serializer that's a simple subclass of DS.ActiveModelSerializer:

// app/serializers/application.js
import DS from "ember-data";

OS X Yosemite Messages database merger

Early betas of OS X Yosemite had a bug where the library of old messages wasn't migrated. Instead a new library was created and all old messages were gone.

The bug has been fixed, but if you were affected, you still have two separate libraries. This script merged them for me. Use it at your own risk! You might end up worse than before. Backup everything beforehand. Twice.

This is what your ~/Library/Messages folder will look like if you're affected:

chat.db

	Originall From: Posted 2015-05-29 http://ubwg.net/b/full-list-of-ffmpeg-flags-and-options

	This is the complete list that’s outputted by ffmpeg when running ffmpeg -h full.

	usage: ffmpeg [options] [[infile options] -i infile]… {[outfile options] outfile}…

	Getting help:
	-h — print basic options
	-h long — print more options
	-h full — print all options (including all format and codec specific options, very long)

	class V1::AddressBooksController < V1::BaseController
	def create
	@address_book = AddressBook.new address_book_params
	unless @address_book.save
	errors = @address_book.errors.to_hash(true)
	render status: 422, json: { errors: errors }
	end
	end

	private