saltstack官方文档——File Server Client API

转自：http://docs.saltstack.com/ref/file_server/file_roots.html

File Server Configuration

The Salt file server is a high performance file server written in ZeroMQ. It manages large files quickly and with little overhead, and has been optimized to handle small files in an extremely efficient manner.

The Salt file server is an environment aware file server. This means that files can be allocated within many root directories and accessed by specifying both the file path and the environment to search. The individual environments can span across multiple directory roots to create overlays and to allow for files to be organized in many flexible ways.

ENVIRONMENTS

The Salt file server defaults to the mandatory base environment. This environment MUST be defined and isused to download files when no environment is specified.

Environments allow for files and sls data to be logically separated, but environments are not isolated from eachother. This allows for logical isolation of environments by the engineer using Salt, but also allows for informationto be used in multiple environments.

DIRECTORY OVERLAY

The environment setting is a list of directories to publish files from. These directories are searched in order to find the specified file and the first file found is returned.

This means that directory data is prioritized based on the order in which they are listed. In the case of thisfile_roots configuration:

file_roots:
  base:
    - /srv/salt/base
    - /srv/salt/failover

If a file's URI is salt://httpd/httpd.conf, it will first search for the file at /srv/salt/base/httpd/httpd.conf. If the file is found there it will be returned. If the file is not found there, then/srv/salt/failover/httpd/httpd.conf will be used for the source.

This allows for directories to be overlaid and prioritized based on the order they are defined in the configuration.

LOCAL FILE SERVER

New in version 0.9.8.

The file server can be rerouted to run from the minion. This is primarily to enable running Salt states without a Salt master. To use the local file server interface, copy the file server data to the minion and set the file_roots option on the minion to point to the directories copied from the master. Once the minion file_roots option has been set, change the file_client option to local to make sure that the local file server interface is used.

转自：http://docs.saltstack.com/ref/file_server/index.html

Salt File Server

Salt comes with a simple file server suitable for distributing files to the Salt minions. The file server is a stateless ZeroMQ server that is built into the Salt master.

The main intent of the Salt file server is to present files for use in the Salt state system. With this said, the Salt file server can be used for any general file transfer from the master to the minions.

THE CP MODULE

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.

Environments

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

The cp.get_file function can be used on the minion to download a file from the master, the syntax looks like this:

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

This will instruct all Salt minions to download the vimrc file and copy it to /etc/vimrc

Template rendering can be enabled on both the source and destination file names like so:

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

This example would instruct all Salt minions to download the vimrc from a directory with the same name as their OS grain and copy it to /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).

Use the gzip named argument to enable it. Valid values are 1..9, where 1 is the lightest compression and 9 the heaviest. 1 uses the least CPU on the master (and minion), 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, env='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, env)

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, env='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, env)