用tsuru部署PHP应用

概述

本文档是在tsuru中部署一个简单的PHP应用的实战指南。例子应用是一个关联MySQL服务的简单Wordpress项目。适用于任何基于apache的php应用。

在tsuru中创建应用

使用app-create命令创建应用：

  1.     $ tsuru app-create <app-name> <app-platform>

对于PHP来说，应用平台是，你猜，php！让我们脑洞大开，开发一个从未有人做过的教学应用：一个博客，而且它的名字也应该是很有创意，让我们叫它blog：

  1.     $ tsuru app-create blog php

使用platform-list命令列出所有的可用的平台。使用app-list查看你所有的应用。

  1.     $ tsuru app-list
  2.     +-------------+-------------------------+--------------------------+
  3.     | Application | Units State Summary     | Address                  |
  4.     +-------------+-------------------------+--------------------------+
  5.     | blog        | 0 of 0 units in-service | blog.192.168.50.4.nip.io |
  6.     +-------------+-------------------------+--------------------------+

应用的代码

本文档不会专注于介绍如何用php实现博客，你可以从wordpress下载完整源码：http://wordpress.org/latest.zip。 下面是在项目中要做的事情：

  1.     # Download and unpack wordpress
  2.     $ wget http://wordpress.org/latest.zip
  3.     $ unzip latest.zip
  4.     # Preparing wordpress for tsuru
  5.     $ cd wordpress
  6.     # Notify tsuru about the necessary packages
  7.     $ echo php5-mysql > requirements.apt
  8.     # Preparing the application to receive the tsuru environment related to the mysql service
  9.     $ sed "s/'database_name_here'/getenv('MYSQL_DATABASE_NAME')/; \
  10.                 s/'username_here'/getenv('MYSQL_USER')/; \
  11.                 s/'localhost'/getenv('MYSQL_HOST')/; \
  12.                 s/'password_here'/getenv('MYSQL_PASSWORD')/" \
  13.                 wp-config-sample.php  > wp-config.php
  14.     # Creating a local Git repository
  15.     $ git init
  16.     $ git add .
  17.     $ git commit -m 'initial project version'

通过Git部署

在创建新的应用时，tsuru会显示你应该使用的Git远程分支。用app-info命令可以获得其信息：

  1.     $ tsuru app-info --app blog
  2.     Application: blog
  3.     Repository: git@192.168.50.4.nip.io:blog.git
  4.     Platform: php
  5.     Teams: admin
  6.     Address: blog.192.168.50.4.nip.io
  7.     Owner: admin@example.com
  8.     Team owner: admin
  9.     Deploys: 0
  10.     Pool: theonepool
  12.     App Plan:
  13.     +---------------+--------+------+-----------+--------+---------+
  14.     | Name          | Memory | Swap | Cpu Share | Router | Default |
  15.     +---------------+--------+------+-----------+--------+---------+
  16.     | autogenerated | 0 MB   | 0 MB | 100       |        | false   |
  17.     +---------------+--------+------+-----------+--------+---------+

Git远程分支被用来通过Git部署应用。当修改被推送到tsuru远程分支时，项目同时也被部署：

  1.     $ git push git@192.168.50.4.nip.io:blog.git master
  2.     Counting objects: 1295, done.
  3.     Delta compression using up to 4 threads.
  4.     Compressing objects: 100% (1271/1271), done.
  5.     Writing objects: 100% (1295/1295), 6.09 MiB | 5.65 MiB/s, done.
  6.     Total 1295 (delta 102), reused 0 (delta 0)
  7.     remote: text
  8.     remote: Deploying the PHP application...
  9.     remote: tar: Removing leading `/' from member names
  10.     #########################################
  11.     #  OMIT DEPENDENCIES STEPS (see below)  #
  12.     #########################################
  13.     remote:
  14.     remote: ---- Building application image ----
  15.     remote:  ---> Sending image to repository (51.40MB)
  16.     remote:  ---> Cleaning up
  17.     remote:
  18.     remote: ---- Starting 1 new unit ----
  19.     remote:  ---> Started unit 027c2a31a0...
  20.     remote:
  21.     remote: ---- Binding and checking 1 new units ----
  22.     remote:  ---> Bound and checked unit 027c2a31a0
  23.     remote:
  24.     remote: ---- Adding routes to 1 new units ----
  25.     remote:  ---> Added route to unit 027c2a31a0
  26.     remote:
  27.     remote: OK
  28.     To git@192.168.50.4.nip.io:blog.git
  29.      * [new branch]      master -> master

如果遇到"Permission denied (publickey)."的错误，请确保你是团队一员并把公钥加到tsuru中。用key-add命令添加公钥：

  1.     $ tsuru key-add mykey ~/.ssh/id_dsa.pub

使用git remote add命令来避免每次push代码时都要输入整个远程仓库的链接：

  1.     $ git remote add tsuru git@192.168.50.4.nip.io:blog.git

然后运行：

  1.     $ git push tsuru master
  2.     Everything up-to-date

从此之后就可以省略掉—app标记:

  1.     $ tsuru app-info
  2.     Application: blog
  3.     Repository: git@192.168.50.4.nip.io:blog.git
  4.     Platform: php
  5.     Teams: admin
  6.     Address: blog.192.168.50.4.nip.io
  7.     Owner: admin@example.com
  8.     Team owner: admin
  9.     Deploys: 1
  10.     Pool: theonepool
  11.     Units: 1
  12.     +------------+---------+
  13.     | Unit       | State   |
  14.     +------------+---------+
  15.     | 027c2a31a0 | started |
  16.     +------------+---------+
  18.     App Plan:
  19.     +---------------+--------+------+-----------+--------+---------+
  20.     | Name          | Memory | Swap | Cpu Share | Router | Default |
  21.     +---------------+--------+------+-----------+--------+---------+
  22.     | autogenerated | 0 MB   | 0 MB | 100       |        | false   |
  23.     +---------------+--------+------+-----------+--------+---------+

列出依赖

在上一个部分我们忽略了部署过程的依赖。在tsuru中，一个应用可以有两种依赖：

  • 操作系统级别的依赖, 以底层操作系统使用的包管理器为代表（比如: yum和apt-get）;
  • 平台依赖, 以平台/语言依赖的包管理工具为代表（在Python中是pip）。
    所有的apt-get依赖必须在requirements.apt文件中指定，放在应用的根目录，同理，pip的依赖也必须放在应用根目录名为requirements.txt的文件中。因为要用PHP连接MySQL，我们只需要用apt-get安装php5-mysql包，因此requirements.apt内容如下：
  1.     php5-mysql

下面是安装这些依赖的完整输出：

  1.     % git push tsuru master
  2.     #####################################
  3.     #                OMIT               #
  4.     #####################################
  5.     Counting objects: 1155, done.
  6.     Delta compression using up to 4 threads.
  7.     Compressing objects: 100% (1124/1124), done.
  8.     Writing objects: 100% (1155/1155), 4.01 MiB | 327 KiB/s, done.
  9.     Total 1155 (delta 65), reused 0 (delta 0)
  10.     remote: Cloning into '/home/application/current'...
  11.     remote: Reading package lists...
  12.     remote: Building dependency tree...
  13.     remote: Reading state information...
  14.     remote: The following extra packages will be installed:
  15.     remote:   libmysqlclient18 mysql-common
  16.     remote: The following NEW packages will be installed:
  17.     remote:   libmysqlclient18 mysql-common php5-mysql
  18.     remote: 0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
  19.     remote: Need to get 1042 kB of archives.
  20.     remote: After this operation, 3928 kB of additional disk space will be used.
  21.     remote: Get:1 http://archive.ubuntu.com/ubuntu/ quantal/main mysql-common all 5.5.27-0ubuntu2 [13.7 kB]
  22.     remote: Get:2 http://archive.ubuntu.com/ubuntu/ quantal/main libmysqlclient18 amd64 5.5.27-0ubuntu2 [949 kB]
  23.     remote: Get:3 http://archive.ubuntu.com/ubuntu/ quantal/main php5-mysql amd64 5.4.6-1ubuntu1 [79.0 kB]
  24.     remote: Fetched 1042 kB in 1s (739 kB/s)
  25.     remote: Selecting previously unselected package mysql-common.
  26.     remote: (Reading database ... 23874 files and directories currently installed.)
  27.     remote: Unpacking mysql-common (from .../mysql-common_5.5.27-0ubuntu2_all.deb) ...
  28.     remote: Selecting previously unselected package libmysqlclient18:amd64.
  29.     remote: Unpacking libmysqlclient18:amd64 (from .../libmysqlclient18_5.5.27-0ubuntu2_amd64.deb) ...
  30.     remote: Selecting previously unselected package php5-mysql.
  31.     remote: Unpacking php5-mysql (from .../php5-mysql_5.4.6-1ubuntu1_amd64.deb) ...
  32.     remote: Processing triggers for libapache2-mod-php5 ...
  33.     remote:  * Reloading web server config
  34.     remote:    ...done.
  35.     remote: Setting up mysql-common (5.5.27-0ubuntu2) ...
  36.     remote: Setting up libmysqlclient18:amd64 (5.5.27-0ubuntu2) ...
  37.     remote: Setting up php5-mysql (5.4.6-1ubuntu1) ...
  38.     remote: Processing triggers for libc-bin ...
  39.     remote: ldconfig deferred processing now taking place
  40.     remote: Processing triggers for libapache2-mod-php5 ...
  41.     remote:  * Reloading web server config
  42.     remote:    ...done.
  43.     remote: sudo: unable to resolve host 8cf20f4da877
  44.     remote: sudo: unable to resolve host 8cf20f4da877
  45.     remote: debconf: unable to initialize frontend: Dialog
  46.     remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
  47.     remote: debconf: falling back to frontend: Readline
  48.     remote: debconf: unable to initialize frontend: Dialog
  49.     remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
  50.     remote: debconf: falling back to frontend: Readline
  51.     remote:
  52.     remote: Creating config file /etc/php5/mods-available/mysql.ini with new version
  53.     remote: debconf: unable to initialize frontend: Dialog
  54.     remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
  55.     remote: debconf: falling back to frontend: Readline
  56.     remote:
  57.     remote: Creating config file /etc/php5/mods-available/mysqli.ini with new version
  58.     remote: debconf: unable to initialize frontend: Dialog
  59.     remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
  60.     remote: debconf: falling back to frontend: Readline
  61.     remote:
  62.     remote: Creating config file /etc/php5/mods-available/pdo_mysql.ini with new version
  63.     remote:
  64.     remote:  ---> App will be restarted, please check its log for more details...
  65.     remote:
  66.     To git@192.168.50.4.nip.io:blog.git
  67.      * [new branch]      master -> master

运行应用

如你所见，部署的输出信息中有一个步骤叫做"重启你的应用"。在这个步骤中，如果应用在运行，tsuru会重启它，如果没有运行，tsuru会启动它。应用部署成功，可以通过app-list命令获得IP或者主机名，然后用浏览器去访问。比如，在下面的列表中：

  1.     $ tsuru app-list
  2.     +-------------+-------------------------+---------------------+
  3.     | Application | Units State Summary     | Address             |
  4.     +-------------+-------------------------+---------------------+
  5.     | blog        | 1 of 1 units in-service | blog.cloud.tsuru.io |
  6.     +-------------+-------------------------+---------------------+

使用服务

php已经在运行，可以用过浏览器访问应用，但是会遇到一个数据库连接错误："Error establishing a database connection"。它的意思是应用无法连接到MySQL。这是因为我们不应该在本地连接MySQL，而是应该使用服务。服务的工作流分为下面两步：

. 创建一个服务的实例. 将服务的实例绑定到应用

但是如何知道哪些服务是可用的呢？这很简单，运行service-list命令：

  1.     $ tsuru service-list
  2.     +----------------+-----------+
  3.     | Services       | Instances |
  4.     +----------------+-----------+
  5.     | elastic-search |           |
  6.     | mysql          |           |
  7.     +----------------+-----------+

上面service-list的输出说明有两个可用的服务："elastic-search"和"mysql"，并且没有实例。通过service-add命令可以创建MySQL实例：

  1.     $ tsuru service-add mysql blogsql
  2.     Service successfully added.

现在，如果再次运行service-list命令，可以从输出中看到新的服务实例：

  1.     $ tsuru service-list
  2.     +----------------+-----------+
  3.     | Services       | Instances |
  4.     +----------------+-----------+
  5.     | elastic-search |           |
  6.     | mysql          | blogsql   |
  7.     +----------------+-----------+

使用service-bind命令将服务实例绑定到应用：

  1.     $ tsuru service-bind mysql blogsql
  2.     Instance blogsql is now bound to the app blog.
  4.     The following environment variables are now available for use in your app:
  6.     - MYSQL_PORT
  7.     - MYSQL_PASSWORD
  8.     - MYSQL_USER
  9.     - MYSQL_HOST
  10.     - MYSQL_DATABASE_NAME
  12.     For more details, please check the documentation for the service, using service-doc command.

从绑定的输出中我们看出，可以通过环境变量来连接MySQL服务器。下一步就是更新wp-config.php，使用这些环境变量去连接数据库：

  1.     $ grep getenv wp-config.php
  2.     define('DB_NAME', getenv('MYSQL_DATABASE_NAME'));
  3.     define('DB_USER', getenv('MYSQL_USER'));
  4.     define('DB_PASSWORD', getenv('MYSQL_PASSWORD'));
  5.     define('DB_HOST', getenv('MYSQL_HOST'));

可以通过在代码库中安装插件来扩展wordress应用。下面的例子中，我们为wordpress添加了Amazon S3的功能，只需要安装两个插件：Amazon S3 and Cloudfront和Amazon Web Services。这是在tsuru保存内容的正确方式。

  1.     $ cd wp-content/plugins/
  2.     $ wget http://downloads.wordpress.org/plugin/amazon-web-services.0.1.zip
  3.     $ wget http://downloads.wordpress.org/plugin/amazon-s3-and-cloudfront.0.6.1.zip
  4.     $ unzip amazon-web-services.0.1.zip
  5.     $ unzip amazon-s3-and-cloudfront.0.6.1.zip
  6.     $ rm -f amazon-web-services.0.1.zip amazon-s3-and-cloudfront.0.6.1.zip
  7.     $ git add amazon-web-services/ amazon-s3-and-cloudfront/

现在需要将AWS_ACCESS_KEY_ID和AWS_SECRET_ACCESS_KEY两个amazon需要的环境变量添加到wp-config.php文件中。可以像下面一样将这些环境变量放在WP_DEBUG后面：

  1.     $ grep -A2 define.*WP_DEBUG  wp-config.php
  2.     define('WP_DEBUG', false);
  3.     define('AWS_ACCESS_KEY_ID', getenv('AWS_ACCESS_KEY_ID'));
  4.     define('AWS_SECRET_ACCESS_KEY', getenv('AWS_SECRET_ACCESS_KEY'));
  5.     $ git add wp-config.php
  6.     $ git commit -m 'adding plugins for S3'
  7.     $ git push tsuru master

然后，像下面一样通过tsuru env-set给这些环境变量设置正确的值：

  2.     $ tsuru env-set AWS_ACCESS_KEY_ID="xxx" AWS_SECRET_ACCESS_KEY="xxxxx" -a blog

完成！现在我们有了一个部署在tsuru上，同时使用MySQL服务以及S3支持的PHP项目。

定制平台

PHP平台支持对前端和解释器的定制。要了解更多细节，请查看平台的介绍文档.

进一步探索

更多信息，可以查看tsuru文档，或者阅读tsuru命令完全使用指南。

原文: http://doc.oschina.net/tsuru-paas?t=52824