python fabric实现远程操作和部署

环境配置
在本机和目标机器安装对应包（注意，都要有）

sudo easy_install fabric
目前是1.8版本（或者用pip install，一样的）

安装完后，可以查看是否安装成功
[ken@~$] which fab
/usr/local/bin/fab
装完之后，可以浏览下官方文档

执行本机操作

from fabric.api import local

def lsfab():
    local('cd ~/tmp/fab')
    local('ls')
结果：

[ken@~/tmp/fab$] pwd;ls
/Users/ken/tmp/fab
fabfile.py   fabfile.pyc  test.py      test.pyc
[ken@~/tmp/fab$] fab -f test.py lsfab
[localhost] local: cd ~/tmp/fab
[localhost] local: ls
fabfile.py  fabfile.pyc test.py     test.pyc

Done.

远端操作
这时候，假设，你要到机器A的/home/ken/project对应项目目录把配置文件更新下来

#!/usr/bin/env python
# encoding: utf-8

from fabric.api import local,cd,run

env.hosts=['user@ip:port',] #ssh要用到的参数
env.password = 'pwd'


def setting_ci():
    local('echo "add and commit settings in local"')
    #刚才的操作换到这里，你懂的

def update_setting_remote():
    print "remote update"
    with cd('~/temp'):   #cd用于进入某个目录
        run('ls -l | wc -l')  #远程操作用run

def update():
    setting_ci()
    update_setting_remote()

然后，执行之：

[ken@~/tmp/fab$] fab -f deploy.py update
[user@ip:port] Executing task 'update'
[localhost] local: echo "add and commit settings in local"
add and commit settings in local
remote update
[user@ip:port] run: ls -l | wc -l
[user@ip:port] out: 12
[user@ip:port] out:

注意，如果不声明env.password，执行到对应机器时会跳出要求输入密码的交互

设置远程服务器host

from fabric.api import run, env

env.user= 'root'
env.hosts = ['host1', 'jazywoo@host2'] #全局host
env.password= '123456'
env.passwords= {
     'host1' : 123456,
     'host2' : 123456789,
}

def taskA():
    run('ls')

def taskB():
    run('whoami')
taskA executed on host1   #执行结果
taskA executed on host2
taskB executed on host1
taskB executed on host2

from fabric.api import env

env.roledefs['webservers'] = ['www1', 'www2', 'www3']

from fabric.api import env

env.roledefs = {
    'web': ['www1', 'www2', 'www3'],
    'dns': ['ns1', 'ns2']
}

from fabric.api import env, run

def set_hosts(): #本地设置host
    env.hosts = ['host1', 'host2']

def mytask():
    run('ls /var/www')

$ fab -H host1,host2 mytask #命令行设置host

$ fab mytask:hosts="host1;host2" 针对任务设置host

from fabric.api import env, run

env.hosts.extend(['host3', 'host4'])   #整合命令行，合并host

def mytask():
    run('ls /var/www')

from fabric.api import hosts, run

@hosts('host1', 'host2')   #使用host修饰来制定host
def mytask():
    run('ls /var/www')

my_hosts = ('host1', 'host2')
@hosts(my_hosts)
def mytask():
    # ...

from fabric.api import env, hosts, roles, run

env.roledefs = {'role1': ['b', 'c']}

@hosts('a', 'b')
@roles('role1')  #使用roles修饰来指定host
def mytask():
    run('ls /var/www')

执行任务execute和run_once

from fabric.api import run, roles, execute

env.roledefs = {
    'db': ['db1', 'db2'],
    'web': ['web1', 'web2', 'web3'],
}

@roles('db')
def migrate():
    # Database stuff here.
    pass

@roles('web')
def update():
    # Code updates here.
    pass

def deploy():
    execute(migrate)   #执行任务 ，多次调用execute可以多次执行，而使用run_once保证只执行一次
    execute(update)

execute得到host结果

from fabric.api import task, execute, run, runs_once

@task
def workhorse():
    return run("get my infos")

@task
@runs_once
def go():
    results = execute(workhorse)
    print results

使用task修饰

from fabric.api import task


@task(alias='dwm') #task别名
def deploy_with_migrations():
    pass

@task
def mytask():
    run("a command")

这样使用终端命令 fab --list可以查看任务列别
也可以使用Task类封装所有操作

class MyTask(Task):
    name = "deploy"
    def run(self, environment, domain="whatever.com"):
        run("git clone foo")
        sudo("service apache2 restart")

instance = MyTask()
============相当于===============
@task
def deploy(environment, domain="whatever.com"):
    run("git clone foo")
    sudo("service apache2 restart")

from fabric.api import task
from fabric.tasks import Task

class CustomTask(Task):
    def __init__(self, func, myarg, *args, **kwargs):
        super(CustomTask, self).__init__(*args, **kwargs)
        self.func = func
        self.myarg = myarg

    def run(self, *args, **kwargs):
        return self.func(*args, **kwargs)

@task(task_class=CustomTask, myarg='value', alias='at')
def actual_task():
    pass

当tabfile执行的时候，实际执行如下：
task_obj = CustomTask(actual_task, myarg='value')

Parallel并行任务
上述任务的执行是串行serially的，

from fabric.api import *

def update():
    with cd("/srv/django/myapp"):
        run("git pull")

def reload():
    sudo("service apache2 reload")

终端执行 $ fab -H web1,web2,web3 update reload 之后结果如下：
1 update on web1
2 update on web2
3 update on web3
4 reload on web1
5 reload on web2
6 reload on web3
而并行结果希望是：
1 update on web1, web2, and web3
2 reload on web1, web2, and web3

并行处理等待的时间更短
from fabric.api import *

@parallel  #使用修饰副
def runs_in_parallel():
    pass

def runs_serially():
    pass

终端 $ fab -H host1,host2,host3 runs_in_parallel runs_serially
结果：
1 runs_in_parallel on host1, host2, and host3
2 runs_serially on host1
3 runs_serially on host2
4 runs_serially on host3
或者直接在终端命令执行时用 —P 参数
$ fab -H host1,host2,host3 -P runs_in_parallel runs_serially

还可以设置并行的个数
from fabric.api import *

@parallel(pool_size=5) #使用pool_size
def heavy_task():
    # lots of heavy local lifting or lots of IO here

$ fab -P -z 5 heavy_task #命令行

关闭远程任务Connection

没有关闭连接。python程序会一直等待新资源发送

from fabric.state import connections

for key in connections.keys():
    connections[key].close()
    del connections[key]

实例

from fabric.api import abort, cd, env, get, hide, hosts, local, prompt, \   #fabric的操作命令
    put, require, roles, run, runs_once, settings, show, sudo, warn


from fabric.api import *

@hosts('host1')
def clean_and_upload():
    local('find assets/ -name "*.DS_Store" -exec rm '{}' \;')
    local('tar czf /tmp/assets.tgz assets/')
    put('/tmp/assets.tgz', '/tmp/assets.tgz')
    with cd('/var/www/myapp/'):
        run('tar xzf /tmp/assets.tgz')