使用dotCloud在云端部署Django应用程序

＃创建我的dotcloud虚拟环境。
$ mkvirtualenv dotcloud

＃使用pip安装dotcloud客户端
$ pip install dotcloud

＃创建我们的博客应用程序
$ dotcloud create blog

# 当收到提示时，输入api密钥，密钥可从这里获得：http://www.dotcloud.com/account/settings
＃<密钥写这里>

＃如果你没有收到输入密钥的提示，可以运行这个命令，它会让你再次输入你的API密钥。
$ dotcloud register

＃进入项目目录
CD ~/projects

＃fork kkecochranenet 到新分支 kencochranenet_dotcloud，然后克隆到本地
git clone git：//github.com/kencochrane/kencochranenet_dotcloud.git kencochranenet_dotcloud

＃进入新的目录。
cd kencochrane_dotcloud

import os
import sys

＃与示例模板不同的是，作者加入了下面这些内容
sys.path.insert（0，os.path.abspath（os.path.join（os.path.dirname（__ file __），'mysite'）））
os.environ ['DJANGO_SETTINGS_MODULE'] ='mysite.settings'

import django.core.handlers.wsgi
djangoapplication = django.core.handlers.wsgi.WSGIHandler()
def application(environ, start_response):
    if 'SCRIPT_NAME' in environ:
        del environ['SCRIPT_NAME']
    return djangoapplication(environ, start_response

import json
with open('/home/dotcloud/environment.json') as f:
  env = json.load(f)

DATABASES = {
    'default'：{
        'ENGINE'：'django.db.backends.mysql'，
        'NAME'：'blogdb'，
        'USER'：env ['DOTCLOUD_DB_MYSQL_LOGIN']，
        'PASSWORD'：env ['DOTCLOUD_DB_MYSQL_PASSWORD']，
        'HOST'：env ['DOTCLOUD_DB_MYSQL_HOST']，
        'PORT'：int（env ['DOTCLOUD_DB_MYSQL_PORT']），
    }
}

＃连接到dotcloud mysql服务器实例
$ dotcloud run blog.db -- mysql -u root -p

＃mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 34
Server version: 5.1.41-3ubuntu12.10 (Ubuntu)

# 创建用户和数据库，并授予用户权限

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create database blogdb;
Query OK, 1 row affected (0.00 sec)

mysql> create user 'blog_username' identified by 'strong_password';
Query OK, 0 rows affected (0.05 sec)

mysql> grant all on blogdb.* to 'blog_user'@'%';
Query OK, 0 rows affected (0.04 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> exit;Bye
Shared connection to database closed.

import MySQLdb
import os
from wsgi import *

def create_dbs(names):
    print("create_dbs: let's go.")
    django_settings = __import__(os.environ['DJANGO_SETTINGS_MODULE'], fromlist='DATABASES')
    print("create_dbs: got settings.")
    databases = django_settings.DATABASES
    for name, db in databases.iteritems():
        if name in names and db['ENGINE'].endswith('mysql'):
            host = db['HOST']
            user = db['USER']
            password = db['PASSWORD']
            port = db['PORT']
            db_name = db['NAME']
            print 'creating database %s on %s' % (db_name, host)
            db = MySQLdb.connect(user=user,
                                passwd=password,
                                host=host,
                                port=port)
            cur = db.cursor()
            print("Check if database is already there.")
            cur.execute("""SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA
                         WHERE SCHEMA_NAME = %s""", (db_name,))
            results = cur.fetchone()
            if not results:
                print("Database %s doesn't exist, lets create it." % db_name)
                sql = """CREATE DATABASE IF NOT EXISTS %s """ % (db_name,)
                print("> %s" % sql)
                cur.execute(sql)
                print(".....")
            else:
                print("database already exists, moving on to next step.")


if __name__ == '__main__':
    import sys
    print("create_dbs start")
    create_dbs(sys.argv[1:])
    print("create_dbs all done")

CACHES = {
    'default'：{
        'BACKEND'：'redis_cache.cache.RedisCache'，
        'LOCATION'：env ['DOTCLOUD_CACHE_REDIS_HOST'] +'：'+ env ['DOTCLOUD_CACHE_REDIS_PORT']，
        'OPTIONS'：{
            'DB'：1，
            'PASSWORD'：env ['DOTCLOUD_CACHE_REDIS_PASSWORD']，
            'PARSER_CLASS'：'redis.connection.HiredisParser'
        },
    },
}

＃我们也将使用redis作为会话缓存。
SESSION_ENGINE ='django.contrib.sessions.backends.cached_db'

#!/usr/bin/env python
from wsgi import *
from django.contrib.auth.models import User
u, created = User.objects.get_or_create(username='admin')
if created:
    u.set_password('P@s$w0rd1')
    u.is_superuser = True
    u.is_staff = True
    u.save()

＃媒体文件设置
MEDIA_ROOT ='/home/dotcloud/data/media/'
MEDIA_URL ='/media/'

＃静态文件设置
STATIC_ROOT ='/home/dotcloud/data/static/'
STATIC_URL ='/static/'

＃管理员前缀
ADMIN_MEDIA_PREFIX ='/static/admin/'

location /media/ {root/home/dotcloud/data; }
location /static/ {root/home/dotcloud/data; }

#!/bin/sh
python createdb.py default
python mysite/manage.py syncdb --noinput
python mysite/manage.py migrate
python mkadmin.py
mkdir -p /home/dotcloud/data/media /home/dotcloud/data/static
python mysite/manage.py collectstatic --noinput

＃使脚本可执行。
$ chmod + x postinstall createdb.py mkadmin.py

www:
  type: python
db:
  type: mysql
cache:
  type: redis

＃推出你的更改到服务器
$ dotcloud push blog

＃获取有关我们新服务的信息
$ dotcloud info blog
cache:
    config:
        redis_password: <password>
        redis_replication: true
    instances: 1
    type: redis
db:
    config:
        mysql_masterslave: true
        mysql_password: <password>
    instances: 1
    type: mysql
www:
    config:
        static: static
        uwsgi_processes: 4
    instances: 1
    type: python
    url: <url was here>

$ dotcloud scale app db=2

www:
  type: python
  config:
    smtp_server: smtp.mailgun.org
    smtp_port: 25
    smtp_username: postmaster@company.com
    smtp_password: YourMailGunPassword

mailer:
  type: smtp
  config:
    smtp_relay_server: smtp.mailgun.org
    smtp_relay_port: 587
    smtp_relay_username: postmaster@yourmailgundomain.com
    smtp_relay_password: YourMailgunPassword

mailer:
  type: smtp
  config:
    smtp_relay_server: smtp.gmail.com
    smtp_relay_port: 587
    smtp_relay_username: your_gmail_username@gmail.com
    smtp_relay_password: Your_Gmail_Password

＃查看日志，打印到控制台。按ctrl-c停止。
$ dotcloud logs blog.www

＃打开一个shell
$ dotcloud ssh blog.www

＃nginx访问和错误日​​志。
/var/log/nginx/<app_name>.{access,error}.log

＃wsgi错误日志
/var/log/supervisor/uswgi.log

＃重新启动服务
dotcloud restart blog.www