Salt文件服务器

Salt内置一个简单的文件服务器用于分发文件给Salt minions. 文件服务器是一个构建于Salt master的无状态的ZeroMQ服务器。

Salt文件服务器的主要意图是使用在Salt state系统中展示文件的。这样看来,Salt文件服务器可以用于任何master到minions的通用文件传输。

cp模块

The cp module is the home of minion side file server operations. The cp module is used by the Salt state system, salt-cp, and can be used to distribute files presented by the Salt file server.

Escaping Special Characters

The salt:// url format can potentially contain a query string, for example salt://dir/file.txt?saltenv=base. You can prevent the fileclient/fileserver from interpreting ? as the initial token of a query string by referencing the file with salt://| rather than salt://.

/etc/marathon/conf/?checkpoint:
  file.managed:
    - source: salt://|hw/config/?checkpoint
    - makedirs: True

环境变量

Since the file server is made to work with the Salt state system, it supports environments. The environments are defined in the master config file and when referencing an environment the file specified will be based on the root directory of the environment.

get_file

cp.get_file功能可以用于minion从master下载一个文件,该语法像这样:

# salt '*' cp.get_file salt://vimrc /etc/vimrc

该指令将会通知所有Salt minions下载vimrc文件并且拷贝到/etc/vimrc

模板渲染功能可以同时在源和目标文件启用,命名像这样:

# salt '*' cp.get_file "salt://{{grains.os}}/vimrc" /etc/vimrc template=jinja

该范例将会通知所有Salt minions下载vimrc从同名目录名下载,作为他们的OS grain并且拷贝到/etc/vimrc

For larger files, the cp.get_file module also supports gzip compression. Because gzip is CPU-intensive, this should only be used in scenarios where the compression ratio is very high (e.g. pretty-printed JSON or YAML files).

To use compression, use the gzip named argument. Valid values are integers from 1 to 9, where 1 is the lightest compression and 9 the heaviest. In other words, 1 uses the least CPU on the master (and minion), while 9 uses the most.

# salt '*' cp.get_file salt://vimrc /etc/vimrc gzip=5

Finally, note that by default cp.get_file does not create new destination directories if they do not exist. To change this, use the makedirs argument:

# salt '*' cp.get_file salt://vimrc /etc/vim/vimrc makedirs=True

In this example, /etc/vim/ would be created if it didn't already exist.

get_dir

The cp.get_dir function can be used on the minion to download an entire directory from the master. The syntax is very similar to get_file:

# salt '*' cp.get_dir salt://etc/apache2 /etc

cp.get_dir supports template rendering and gzip compression arguments just like get_file:

# salt '*' cp.get_dir salt://etc/{{pillar.webserver}} /etc gzip=5 template=jinja

File Server Client API

A client API is available which allows for modules and applications to be written which make use of the Salt file server.

The file server uses the same authentication and encryption used by the rest of the Salt system for network communication.

FileClient Class

The FileClient class is used to set up the communication from the minion to the master. When creating a FileClient object the minion configuration needs to be passed in. When using the FileClient from within a minion module the built in __opts__ data can be passed:

import salt.minion

def get_file(path, dest, saltenv='base'):
    '''
    Used to get a single file from the Salt master

    CLI Example:
    salt '*' cp.get_file salt://vimrc /etc/vimrc
    '''
    # Create the FileClient object
    client = salt.minion.FileClient(__opts__)
    # Call get_file
    return client.get_file(path, dest, False, saltenv)

Using the FileClient class outside of a minion module where the __opts__ data is not available, it needs to be generated:

import salt.minion
import salt.config

def get_file(path, dest, saltenv='base'):
    '''
    Used to get a single file from the Salt master
    '''
    # Get the configuration data
    opts = salt.config.minion_config('/etc/salt/minion')
    # Create the FileClient object
    client = salt.minion.FileClient(opts)
    # Call get_file
    return client.get_file(path, dest, False, saltenv)