【SaltStack官方版】—— states教程, part 2

states tutorial, part 2 - more complex states, requisites

本教程建立在第1部分涵盖的主题上。建议您从此处开始。

在Salt States教程的最后一部分，我们简单的介绍了基本的安装一个软件包，我们现在将修改我们的webserver.sls文件以满足要求，并使用更多的Salt States

call multiple states(调用多状态)

You can specify multiple State declaration under an ID declaration. For example, a quick modification to our webserver.sls to also start Apache if it is not running:

你可以在ID声明下指定多个State声明。例如，对我们的webserver.sls进行快速修改，以便在未运行时启动Apache：

apache:
  pkg.installed: []
  service.running:
    - require:
      - pkg: apache

Try stopping Apache before running state.apply once again and observe the output.

尝试先关闭正在运行的apache服务然后运行state.highstate仔细看看的输出.

require other states

We now have a working installation of Apache so let's add an HTML file to customize our website. It isn't exactly useful to have a website without a webserver so we don't want Salt to install our HTML file until Apache is installed and running. Include the following at the bottom of your webserver/init.sls file:

我们现在只是进行一个apache应用的安装工作，所以接下来我们将添加一个html 文件来定制我们的web服务器。没有web服务器的网站并不是很有用，所以我们不希望Salt在Apache安装并运行之前安装我们的HTML文件。我们可以在webserver/init.sls的底部添加下面的内容：

 1 apache:
 2   pkg.installed: []
 3   service.running:
 4     - require:
 5       - pkg: apache
 6 
 7 /var/www/index.html:                        # ID declaration
 8   file:                                     # state declaration
 9     - managed                               # function
10     - source: salt://webserver/index.html   # function arg
11     - require:                              # requisite declaration
12       - pkg: apache                         # requisite reference

line 7 is the ID declaration. In this example it is the location we want to install our custom HTML file. (Note: the default location that Apache serves may differ from the above on your OS or distro. /srv/www could also be a likely place to look.)

第7行是ID声明。在这个例子中，它是我们想要安装我们的自定义HTML文件的位置。(注意：Apache服务的默认位置可能与您的操作系统或发行版上述不同。/ srv / www也可能是一个可能的地方。)

Line 8 the State declaration. This example uses the Salt file state.

第8行是State声明。这个例子使用salt的file状态模块文件。

Line 9 is the Function declaration. The managed function will download a file from the master and install it in the location specified.

第9行是函数声明。managed功能将从主站下载文件并将其安装在指定的位置。

Line 10 is a Function arg declaration which, in this example, passes the source argument to the managed function.

第10行是一个Function arg声明，在这个例子中，将源参数传递给managed函数。

Line 11 is a Requisite declaration.

第11行是一个必要的声明。

Line 12 is a Requisite reference which refers to a state and an ID. In this example, it is referring to the ID declaration from our example in part 1. This declaration tells Salt not to install the HTML file until Apache is installed.

第12行是一个必要的参考，它指的是一个状态和一个ID。在本例中，它指的是第1部分中示例中的ID声明。该声明告诉Salt不要在安装Apache之前安装HTML文件。

Next, create the index.html file and save it in the webserver directory:

下一步，创建index.html文件和把它保存在webserver目录：

<!DOCTYPE html>
<html>
    <head><title>Salt rocks</title></head>
    <body>
        <h1>This file brought to you by Salt</h1>
    </body>
</html>

Last, call state.apply again and the minion will fetch and execute the highstate as well as our HTML file from the master using Salt's File Server:

最后，我们再次运行 state.apply,minion将使用Salt的文件服务器从主文件中获取并执行highstate和我们的HTML文件：

salt '*' state.apply

Verify that Apache is now serving your custom HTML.

验证Apache是否正在为您的自定义HTML提供服务。

require vs. watch

There are two Requisite declaration, “require”, and “watch”. Not every state supports “watch”. The service state does support “watch” and will restart a service based on the watch condition.

有两个Requisite声明，“require”和“watch”。并非每个state都支持“watch”。服务状态确实支持“watch”，并将根据监视条件重新启动服务。

For example, if you use Salt to install an Apache virtual host configuration file and want to restart Apache whenever that file is changed you could modify our Apache example from earlier as follows:

例如，如果您使用Salt来安装Apache虚拟主机配置文件并希望在文件更改时重新启动Apache，则可以按照以下方式修改我们的Apache示例：

 1 /etc/httpd/extra/httpd-vhosts.conf:
 2   file.managed:
 3     - source: salt://webserver/httpd-vhosts.conf
 4 
 5 apache:
 6   pkg.installed: []
 7   service.running:
 8     - watch:
 9       - file: /etc/httpd/extra/httpd-vhosts.conf
10     - require:
11       - pkg: apache

If the pkg and service names differ on your OS or distro of choice you can specify each one separately using a Name declaration which explained in Part 3.

如果您的操作系统或发行版中的pkg和服务名称不同，则可以使用第3部分中介绍的名称声明分别指定每个名称和服务名称。

引申：

match : 配模某个模块，比如 match: grain match: nodegroup
require： 依赖某个state，在运行此state前，先运行依赖的state，依赖可以有多个
watch ： 在某个state变化时运行此模块,watch除具备require功能外，还增了关注状态的功能。
order ： 优先级比require和watch低，有order指定的state比没有order指定的优先级高,假如一个state模块内安装多个服务，或者其他依赖关系，可以使用