Cheng Long ChengLong

Fixing grocer

If you use grocer for sending push, you may have notificed that one bad token can cause connection to drop and all subsequent tokens are not sent. And it fails silently... More on this here.

One workaround is to use this pull request (it's not merged in yet). After each push, you call

reply = pusher.read_reply

, which will try to get feedback from Apple. And if the connection is already dropped, it will reconnect. This is exactly what we want. e.g.

I found many misleading guides on how to install SSL certificate so that both http and https can work for the same site. Below are the step by step instructions

Enable mod_ssl, sudo a2enmod ssl
Put your certificate in /etc/ssl/certs/example.com.crt. Other directory may work, but I prefer this.
Put your key in /etc/ssl/private/example.com.key. Other directory may work, but I prefer this.

Add a new virtual host for https, e.g.

<VirtualHost *:443>
    DocumentRoot /path/to/project

ServerName example.com

If you find that your cronjobs are not launched at the specified time, chances are it's a timezone issue.

The timezone of cron is specified in /etc/timezone, according to cron's man page:

The daemon will use, if present, the definition from /etc/timezone for the timezone.

If you change the timezone of the machine but has NOT restart cron, cron will still use the old timezone. In order to make your timezone effective, restart cron sudo service cron restart.

Install Command-T

Short summary of the official doc

Prerequisite

Vim compiled with Ruby support. To verify this, run :ruby puts RUBY_VERSION. If it does NOT output error message, this vim has ruby support. Remember this version number. It will be used later.
Pathogen or other vim plugin manager.

Installation

To make your server more secure, it's a good idea to disable root login and password authentication.

Open /etc/ssh/sshd_config

Make sure ssh with pub key is enabled

RSAAuthentication yes
PubkeyAuthentication yes

	require 'bcrypt'

	class User < ActiveRecord::Base
	include BCrypt

	def password
	@password \|\|= Password.new(password_hash)
	end

	def password=(new_password)

	If you see 403 Forbidden when running your app with Apache, it's because Apache is too strict on permissions. Set the following in virtual host config.

	```
	<Directory "/home/your_app/public">
	Options FollowSymLinks
	AllowOverride None
	Order allow,deny
	Allow from all
	Options -MultiViews
	# Uncomment this if you're on Apache >= 2.4:

	require 'houston'
	require 'gcm'

	module Pusher
	APN = Houston::Client.production
	APN.certificate = File.read(File.expand_path('path/to/push_cert.pem', __FILE__))

	# Apple has hard limit on the payload of push notification. The maximum size allowed for a notification payload is 256 bytes;
	# If you have other fields in the notification, you need to tweak this value to fit your needs. Be careful about this.
	MAX_ALERT_LENGTH = 140

	# create a 4G swap file at /swapfile
	sudo fallocate -l 4G /swapfile
	sudo chmod 600 /swapfile
	sudo mkswap /swapfile
	sudo swapon /swapfile

	# Make the Swap File Permanent
	sudo echo "/swapfile none swap sw 0 0" >> /etc/fstab

	# set swappiness to 10

	sudo gem install passenger

	# install dependencies
	sudo apt-get install -y libcurl4-openssl-dev apache2 apache2-prefork-dev libapr1-dev libaprutil1-dev

	# follow instructions
	sudo passenger-install-apache2-module