Python—自动化部署工具：Fabric
Fabric是python编写的一款自动化部署工具
Fabric依赖paramiko进行SSH交互，某种意义上Fabric是对paramiko的封装，封装完成后，不需要像使用paramiko一样处理SSH连接，只需专心于自己的需求即可。
Fabric的设计思路的是提供简单的API来完成所有部署，因此，Fabric对基本的系统管理操作进行了封装。
本篇文章主要针对Python3
fabric最常用的用法是通过SSH连接远程服务器执行Shell命令，然后拿到结果（可选），默认情况下，远程命令的输出直接被捕获并打印在终端上，以下为官网示例：
>>> from fabric import Connection >>> c = Connection('web1') >>> result = c.run('uname -s') Linux >>> result.stdout.strip() == 'Linux' True >>> result.exited 0 >>> result.ok True >>> result.command 'uname -s' >>> result.connection <Connection host=web1> >>> result.connection.host 'web1'
这里遇到问题，安装上述方式并不能成功直接报错：
In [46]: c = Connection('host2')
In [48]: result = c.run("uname -s")
---------------------------------------------------------------------------
SSHException Traceback (most recent call last)
<ipython-input-48-688064d71ccd> in <module>
----> 1 result = c.run("uname -s")
<decorator-gen-3> in run(self, command, **kwargs)
/usr/python/lib/python3.7/site-packages/fabric/connection.py in opens(method, self, *args, **kwargs)
27 @decorator
28 def opens(method, self, *args, **kwargs):
---> 29 self.open()
30 return method(self, *args, **kwargs)
31
/usr/python/lib/python3.7/site-packages/fabric/connection.py in open(self)
613 del kwargs["key_filename"]
614 # Actually connect!
--> 615 self.client.connect(**kwargs)
616 self.transport = self.client.get_transport()
617
/usr/python/lib/python3.7/site-packages/paramiko/client.py in connect(self, hostname, port, username, password, pkey, key_filename, timeout, allow_agent, look_for_keys, compress, sock, gss_auth, gss_kex, gss_deleg_creds, gss_host, banner_timeout, auth_timeout, gss_trust_dns, passphrase)
435 gss_deleg_creds,
436 t.gss_host,
--> 437 passphrase,
438 )
439
/usr/python/lib/python3.7/site-packages/paramiko/client.py in _auth(self, username, password, pkey, key_filenames, allow_agent, look_for_keys, gss_auth, gss_kex, gss_deleg_creds, gss_host, passphrase)
748 if saved_exception is not None:
749 raise saved_exception
--> 750 raise SSHException("No authentication methods available")
751
752 def _log(self, level, msg):
SSHException: No authentication methods available
查看fabric connection源码：
connection.py源码如下：
class Connection(Context): """ A connection to an SSH daemon, with methods for commands and file transfer. **Basics** This class inherits from Invoke's `~invoke.context.Context`, as it is a context within which commands, tasks etc can operate. It also encapsulates a Paramiko `~paramiko.client.SSHClient` instance, performing useful high level operations with that `~paramiko.client.SSHClient` and `~paramiko.channel.Channel` instances generated from it. **Lifecycle** `.Connection` has a basic "`create <__init__>`, `connect/open <open>`, `do work <run>`, `disconnect/close <close>`" lifecycle: - `Instantiation <__init__>` imprints the object with its connection parameters (but does **not** actually initiate the network connection). - An alternate constructor exists for users :ref:`upgrading piecemeal from Fabric 1 <from-v1>`: `from_v1` - Methods like `run`, `get` etc automatically trigger a call to `open` if the connection is not active; users may of course call `open` manually if desired. - Connections do not always need to be explicitly closed; much of the time, Paramiko's garbage collection hooks or Python's own shutdown sequence will take care of things. **However**, should you encounter edge cases (for example, sessions hanging on exit) it's helpful to explicitly close connections when you're done with them. This can be accomplished by manually calling `close`, or by using the object as a contextmanager:: with Connection('host') as c: c.run('command') c.put('file') .. note:: This class rebinds `invoke.context.Context.run` to `.local` so both remote and local command execution can coexist. **Configuration** Most `.Connection` parameters honor :doc:`Invoke-style configuration </concepts/configuration>` as well as any applicable :ref:`SSH config file directives <connection-ssh-config>`. For example, to end up with a connection to ``admin@myhost``, one could: - Use any built-in config mechanism, such as ``/etc/fabric.yml``, ``~/.fabric.json``, collection-driven configuration, env vars, etc, stating ``user: admin`` (or ``{"user": "admin"}``, depending on config format.) Then ``Connection('myhost')`` would implicitly have a ``user`` of ``admin``. - Use an SSH config file containing ``User admin`` within any applicable ``Host`` header (``Host myhost``, ``Host *``, etc.) Again, ``Connection('myhost')`` will default to an ``admin`` user. - Leverage host-parameter shorthand (described in `.Config.__init__`), i.e. ``Connection('admin@myhost')``. - Give the parameter directly: ``Connection('myhost', user='admin')``. The same applies to agent forwarding, gateways, and so forth. .. versionadded:: 2.0 """ # NOTE: these are initialized here to hint to invoke.Config.__setattr__ # that they should be treated as real attributes instead of config proxies. # (Additionally, we're doing this instead of using invoke.Config._set() so # we can take advantage of Sphinx's attribute-doc-comment static analysis.) # Once an instance is created, these values will usually be non-None # because they default to the default config values. host = None original_host = None user = None port = None ssh_config = None gateway = None forward_agent = None connect_timeout = None connect_kwargs = None client = None transport = None _sftp = None _agent_handler = None @classmethod def from_v1(cls, env, **kwargs): """ Alternate constructor which uses Fabric 1's ``env`` dict for settings. All keyword arguments besides ``env`` are passed unmolested into the primary constructor. .. warning:: Because your own config overrides will win over data from ``env``, make sure you only set values you *intend* to change from your v1 environment! For details on exactly which ``env`` vars are imported and what they become in the new API, please see :ref:`v1-env-var-imports`. :param env: An explicit Fabric 1 ``env`` dict (technically, any ``fabric.utils._AttributeDict`` instance should work) to pull configuration from. .. versionadded:: 2.4 """ # TODO: import fabric.state.env (need good way to test it first...) # TODO: how to handle somebody accidentally calling this in a process # where 'fabric' is fabric 2, and there's no fabric 1? Probably just a # re-raise of ImportError?? # Our only requirement is a non-empty host_string if not env.host_string: raise InvalidV1Env( "Supplied v1 env has an empty `host_string` value! Please make sure you're calling Connection.from_v1 within a connected Fabric 1 session." # noqa ) # TODO: detect collisions with kwargs & except instead of overwriting? # (More Zen of Python compliant, but also, effort, and also, makes it # harder for users to intentionally overwrite!) connect_kwargs = kwargs.setdefault("connect_kwargs", {}) kwargs.setdefault("host", env.host_string) shorthand = derive_shorthand(env.host_string) # TODO: don't we need to do the below skipping for user too? kwargs.setdefault("user", env.user) # Skip port if host string seemed to have it; otherwise we hit our own # ambiguity clause in __init__. v1 would also have been doing this # anyways (host string wins over other settings). if not shorthand["port"]: # Run port through int(); v1 inexplicably has a string default... kwargs.setdefault("port", int(env.port)) # key_filename defaults to None in v1, but in v2, we expect it to be # either unset, or set to a list. Thus, we only pull it over if it is # not None. if env.key_filename is not None: connect_kwargs.setdefault("key_filename", env.key_filename) # Obtain config values, if not given, from its own from_v1 # NOTE: not using setdefault as we truly only want to call # Config.from_v1 when necessary. if "config" not in kwargs: kwargs["config"] = Config.from_v1(env) return cls(**kwargs) # TODO: should "reopening" an existing Connection object that has been # closed, be allowed? (See e.g. how v1 detects closed/semi-closed # connections & nukes them before creating a new client to the same host.) # TODO: push some of this into paramiko.client.Client? e.g. expand what # Client.exec_command does, it already allows configuring a subset of what # we do / will eventually do / did in 1.x. It's silly to have to do # .get_transport().open_session(). def __init__( self, host, user=None, port=None, config=None, gateway=None, forward_agent=None, connect_timeout=None, connect_kwargs=None, inline_ssh_env=None, ): """ Set up a new object representing a server connection. :param str host: the hostname (or IP address) of this connection. May include shorthand for the ``user`` and/or ``port`` parameters, of the form ``user@host``, ``host:port``, or ``user@host:port``. .. note:: Due to ambiguity, IPv6 host addresses are incompatible with the ``host:port`` shorthand (though ``user@host`` will still work OK). In other words, the presence of >1 ``:`` character will prevent any attempt to derive a shorthand port number; use the explicit ``port`` parameter instead. .. note:: If ``host`` matches a ``Host`` clause in loaded SSH config data, and that ``Host`` clause contains a ``Hostname`` directive, the resulting `.Connection` object will behave as if ``host`` is equal to that ``Hostname`` value. In all cases, the original value of ``host`` is preserved as the ``original_host`` attribute. Thus, given SSH config like so:: Host myalias Hostname realhostname a call like ``Connection(host='myalias')`` will result in an object whose ``host`` attribute is ``realhostname``, and whose ``original_host`` attribute is ``myalias``. :param str user: the login user for the remote connection. Defaults to ``config.user``. :param int port: the remote port. Defaults to ``config.port``. :param config: configuration settings to use when executing methods on this `.Connection` (e.g. default SSH port and so forth). Should be a `.Config` or an `invoke.config.Config` (which will be turned into a `.Config`). Default is an anonymous `.Config` object. :param gateway: An object to use as a proxy or gateway for this connection. This parameter accepts one of the following: - another `.Connection` (for a ``ProxyJump`` style gateway); - a shell command string (for a ``ProxyCommand`` style style gateway). Default: ``None``, meaning no gatewaying will occur (unless otherwise configured; if one wants to override a configured gateway at runtime, specify ``gateway=False``.) .. seealso:: :ref:`ssh-gateways` :param bool forward_agent: Whether to enable SSH agent forwarding. Default: ``config.forward_agent``. :param int connect_timeout: Connection timeout, in seconds. Default: ``config.timeouts.connect``. :param dict connect_kwargs: Keyword arguments handed verbatim to `SSHClient.connect <paramiko.client.SSHClient.connect>` (when `.open` is called). `.Connection` tries not to grow additional settings/kwargs of its own unless it is adding value of some kind; thus, ``connect_kwargs`` is currently the right place to hand in parameters such as ``pkey`` or ``key_filename``. Default: ``config.connect_kwargs``. :param bool inline_ssh_env: Whether to send environment variables "inline" as prefixes in front of command strings (``export VARNAME=value && mycommand here``), instead of trying to submit them through the SSH protocol itself (which is the default behavior). This is necessary if the remote server has a restricted ``AcceptEnv`` setting (which is the common default). The default value is the value of the ``inline_ssh_env`` :ref:`configuration value <default-values>` (which itself defaults to ``False``). .. warning:: This functionality does **not** currently perform any shell escaping on your behalf! Be careful when using nontrivial values, and note that you can put in your own quoting, backslashing etc if desired. Consider using a different approach (such as actual remote shell scripts) if you run into too many issues here. .. note:: When serializing into prefixed ``FOO=bar`` format, we apply the builtin `sorted` function to the env dictionary's keys, to remove what would otherwise be ambiguous/arbitrary ordering. .. note:: This setting has no bearing on *local* shell commands; it only affects remote commands, and thus, methods like `.run` and `.sudo`. :raises ValueError: if user or port values are given via both ``host`` shorthand *and* their own arguments. (We `refuse the temptation to guess`_). .. _refuse the temptation to guess: http://zen-of-python.info/ in-the-face-of-ambiguity-refuse-the-temptation-to-guess.html#12 .. versionchanged:: 2.3 Added the ``inline_ssh_env`` parameter. """ # NOTE: parent __init__ sets self._config; for now we simply overwrite # that below. If it's somehow problematic we would want to break parent # __init__ up in a manner that is more cleanly overrideable. super(Connection, self).__init__(config=config) #: The .Config object referenced when handling default values (for e.g. #: user or port, when not explicitly given) or deciding how to behave. if config is None: config = Config() # Handle 'vanilla' Invoke config objects, which need cloning 'into' one # of our own Configs (which grants the new defaults, etc, while not # squashing them if the Invoke-level config already accounted for them) elif not isinstance(config, Config): config = config.clone(into=Config) self._set(_config=config) # TODO: when/how to run load_files, merge, load_shell_env, etc? # TODO: i.e. what is the lib use case here (and honestly in invoke too) shorthand = self.derive_shorthand(host) host = shorthand["host"] err = "You supplied the {} via both shorthand and kwarg! Please pick one." # noqa if shorthand["user"] is not None: if user is not None: raise ValueError(err.format("user")) user = shorthand["user"] if shorthand["port"] is not None: if port is not None: raise ValueError(err.format("port")) port = shorthand["port"] # NOTE: we load SSH config data as early as possible as it has # potential to affect nearly every other attribute. #: The per-host SSH config data, if any. (See :ref:`ssh-config`.) self.ssh_config = self.config.base_ssh_config.lookup(host) self.original_host = host #: The hostname of the target server. self.host = host if "hostname" in self.ssh_config: # TODO: log that this occurred? self.host = self.ssh_config["hostname"] #: The username this connection will use to connect to the remote end. self.user = user or self.ssh_config.get("user", self.config.user) # TODO: is it _ever_ possible to give an empty user value (e.g. # user='')? E.g. do some SSH server specs allow for that? #: The network port to connect on. self.port = port or int(self.ssh_config.get("port", self.config.port)) # Gateway/proxy/bastion/jump setting: non-None values - string, # Connection, even eg False - get set directly; None triggers seek in # config/ssh_config #: The gateway `.Connection` or ``ProxyCommand`` string to be used, #: if any. self.gateway = gateway if gateway is not None else self.get_gateway() # NOTE: we use string above, vs ProxyCommand obj, to avoid spinning up # the ProxyCommand subprocess at init time, vs open() time. # TODO: make paramiko.proxy.ProxyCommand lazy instead? if forward_agent is None: # Default to config... forward_agent = self.config.forward_agent # But if ssh_config is present, it wins if "forwardagent" in self.ssh_config: # TODO: SSHConfig really, seriously needs some love here, god map_ = {"yes": True, "no": False} forward_agent = map_[self.ssh_config["forwardagent"]] #: Whether agent forwarding is enabled. self.forward_agent = forward_agent if connect_timeout is None: connect_timeout = self.ssh_config.get( "connecttimeout", self.config.timeouts.connect ) if connect_timeout is not None: connect_timeout = int(connect_timeout) #: Connection timeout self.connect_timeout = connect_timeout #: Keyword arguments given to `paramiko.client.SSHClient.connect` when #: `open` is called. self.connect_kwargs = self.resolve_connect_kwargs(connect_kwargs) #: The `paramiko.client.SSHClient` instance this connection wraps. client = SSHClient() client.set_missing_host_key_policy(AutoAddPolicy()) self.client = client #: A convenience handle onto the return value of #: ``self.client.get_transport()``. self.transport = None if inline_ssh_env is None: inline_ssh_env = self.config.inline_ssh_env #: Whether to construct remote command lines with env vars prefixed #: inline. self.inline_ssh_env = inline_ssh_env
connection 成员变量：
host = None # 主机名或IP地址: www.host.com, 66.66.66.66 original_host = None # 同host user = None # 系统用户名: root, someone port = None # 端口号（远程执行某些应用需提供） gateway = None # 网关 forward_agent = None # 代理 connect_timeout = None # 超时时间 connect_kwargs = None # 连接参数 重要
client = None # 客户端
构造函数参数：
Connection.__init__()
host
user=None
port=None
config=None
gateway=None
forward_agent=None
connect_timeout=None
connect_kwargs=None
这里比较重要的参数是 config和 connection_kwargs
构造函数主体：
config
super(Connection, self).__init__(config=config)
if config is None:
config = Config()
elif not isinstance(config, Config):
config = config.clone(into=Config)
self._set(_config=config)
config成员变量是一个 Config对象，它是调用父类 Context.__init__()方法来初始化的。 Context.__init__()定义如下:
class Context(DataProxy): def __init__(self, config=None): config = config if config is not None else Config() self._set(_config=config) command_prefixes = list() self._set(command_prefixes=command_prefixes) command_cwds = list() self._set(command_cwds=command_cwds)
Context.__init__()初始化时调用 _set()绑定了 Config成员对象 _config:
def _set(self, *args, **kwargs): if args: object.__setattr__(self, *args) for key, value in six.iteritems(kwargs): object.__setattr__(self, key, value)
再通过加了 @property的 config()函数，使得 connection对象能直接用 self.config来引用 _config:
@property def config(self): return self._config @config.setter def config(self, value): self._set(_config=value)
host, user, port
shorthand = self.derive_shorthand(host) host = shorthand["host"] err = ( "You supplied the {} via both shorthand and kwarg! Please pick one." # noqa ) if shorthand["user"] is not None: if user is not None: raise ValueError(err.format("user")) user = shorthand["user"] if shorthand["port"] is not None: if port is not None: raise ValueError(err.format("port")) port = shorthand["port"]
这里是处理host参数的， host可以有一下几种传参形式
user@host:port # 例如: root@10.10.10.10:6666 user@host # 例如: root@10.10.10.10 host:port # 例如: 10.10.10.10:6666 host # 例如: 10.10.10.10
前三种会调用 self.derive_shorthand(host)分别解析出 self.host， self.user和 self.port，最后一种需单独传入 user，port。
如果用前三种传入方式的话，不能再重复传入 user或 port了，会抛出异常
以上分析
定位报错位置：
kwargs = dict(
self.connect_kwargs,
username=self.user,
hostname=self.host,
port=self.port,
)
if self.gateway:
kwargs["sock"] = self.open_gateway()
if self.connect_timeout:
kwargs["timeout"] = self.connect_timeout
# Strip out empty defaults for less noisy debugging
if "key_filename" in kwargs and not kwargs["key_filename"]:
del kwargs["key_filename"]
# Actually connect!
self.client.connect(**kwargs)/usr/python/lib/python3.7/site-packages/paramiko/client.py in connect(self, hostname, port, username, password, pkey, key_filename, timeout, allow_agent, look_for_keys, compress, sock, gss_auth, gss_kex, gss_deleg_creds, gss_host, banner_timeout, auth_timeout, gss_trust_dns, passphrase)
435 gss_deleg_creds,
436 t.gss_host,
--> 437 passphrase,
438 )可以看到，在执行connect方法的时候解析参数错误，这里我们没有传递passphrase参数，导致ssh连接报错
传参的时候是将kwargs传了过去，刚才我们的参数里面缺少self.connect_kwargs这个参数
connect的定义为：
def connect( self, hostname, port=SSH_PORT, username=None, password=None, # 你 pkey=None, # 你 key_filename=None, # 还有你 timeout=None, allow_agent=True, look_for_keys=True, compress=False, sock=None, gss_auth=False, gss_kex=False, gss_deleg_creds=True, gss_host=None, banner_timeout=None, auth_timeout=None, gss_trust_dns=True, passphrase=None, )
使用password方式:
In [27]: c = Connection('47.104.148.179',user='root', connect_kwargs={'password':'your password'}) In [28]: result = c.run('uname -s') Linux In [29]: result.stdout.strip() == "Linux" Out[29]: True In [30]: result.exited Out[30]: 0 In [31]: result.ok Out[31]: True In [32]: result.command Out[32]: 'uname -s' In [33]: result.connection Out[33]: <Connection host=47.104.148.179> In [39]: result.connection.host Out[39]: '47.104.148.179
使用key_filename方式：
In [11]: c = Connection('47.104.148.179', user='root', connect_kwargs={'key_filename':'/root/.ssh/authorized_keys'}
...: )
In [12]: c.run("uname -s")
Linux
Out[12]: <Result cmd='uname -s' exited=0>
In [13]: c.run("ls")
coding_time
comment_tree
python_document_manage
python_linux_automation
python_linux_manage
python_linux_monitor
python_linux_network_manage
sys_back
sys_manager
Out[13]: <Result cmd='ls' exited=0>
通过run命令使用sudo提权执行命令
>>> from fabric import Connection
>>> c = Connection('db1')
>>> c.run('sudo useradd mydbuser', pty=True)
[sudo] password:
<Result cmd='sudo useradd mydbuser' exited=0>
>>> c.run('id -u mydbuser')
1001
<Result cmd='id -u mydbuser' exited=0>auto-response
自动响应：
当用户是普通用户的时候，可以使用run里面的watchers用法，进行自动响应
添加用户
In [21]: c.run('useradd mydbuser', pty=True)
Out[21]: <Result cmd='useradd mydbuser' exited=0>
In [23]: c.run('id mydbuser')
uid=1003(mydbuser) gid=1003(mydbuser) groups=1003(mydbuser)
Out[23]: <Result cmd='id mydbuser' exited=0>执行命令
In [21]: from invoke import Responder In [22]: from fabric import Connection In [23]: c = Connection('47.104.148.179', user='ykyk', connect_kwargs={'password':'123456'})
In [30]: sudopass = Responder(
...: pattern=r'\[sudo\] password for ykyk:',
...: response='xxxxxxx\n',
...:
In [29]: c.run('sudo whoami', pty=True, watchers=[sudopass])
[sudo] password for ykyk: root
Out[29]: <Result cmd='sudo whoami' exited=0>
高级用法：
watchers/responders 在上一步很有效，但是每次使用使用时都要设置一次模板，在实际环境中不够便利，
Invoke提供 Context.sudo 方法，这个方法能够处理大部分常用情况，而不会越权
使用这个方法之前必须保证用户密码已经存储在环境变量中，剩余的就可以交给Connection.sudo来解决
示例如下：
>>> import getpass >>> from fabric import Connection, Config >>> sudo_pass = getpass.getpass("What's your sudo password?") What's your sudo password? >>> config = Config(overrides={'sudo': {'password': sudo_pass}}) >>> c = Connection('db1', config=config) >>> c.sudo('whoami', hide='stderr') root <Result cmd="...whoami" exited=0> >>> c.sudo('useradd mydbuser') <Result cmd="...useradd mydbuser" exited=0> >>> c.run('id -u mydbuser') 1001 <Result cmd='id -u mydbuser' exited=0>
传输文件
In [1]: ls coding_time python_document_manage/ python_linux_manage/ python_linux_network_manage/ sys_manager/ comment_tree/ python_linux_automation/ python_linux_monitor/ sys_back/ In [2]: from fabric import Connection In [3]: result = Connection('own').put('coding_time', remote='/tmp/') In [4]: print('Upload {0.local} to {0.remote}'.format(result)) Upload /root/coding_time to /tmp/coding_time
多任务整合
示例：
当我们需要上传某个文件到服务器并解压到特定目录时，可以这样写：
In [1]: ls
binlog2sql-master/ paramiko-master.zip vim81/
cclang/ Pydiction-master/ vim-8.1.tar.bz2
c_study/ Pydiction-master.zip vim-master/
master.zip pyenv-master.zip vim-master.zip
mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz pyenv-virtualenv-master.zip vim-snipmate/
paramiko-master/ rabbitmq-server-3.6.6-1.el7.noarch.rpm
In [2]: from fabric import Connection
In [3]: c = Connection('own')
In [4]: c.put('mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz','/tmp')
Out[4]: <fabric.transfer.Result at 0x7fedf9e36518>
In [6]: c.run('tar xf /tmp/mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz -C /tmp')
Out[6]: <Result cmd='tar xf /tmp/mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz -C /tmp' exited=0>这里我们可以直接封装成一个方法：
In [7]: def upload_file(c):
...: c.put('mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz','/tmp')
...: c.run('tar xf /tmp/mysql-8.0.13-linux-glibc2.12-x86_64.tar.xz -C /tmp')在多个服务器上执行命令
In [3]: for host in ('own', 'redis','mysql_test'):
...: result = Connection(host).run('uname -s')
...: print("{}: {}".format(host, result.stdout.strip()))
...:
Linux
own: Linux
Linux
redis: Linux
Linux
mysql_test: Linux
还可以使用fabric中的SerialGroup方法：
In [4]: from fabric import SerialGroup as Group In [5]: results = Group('own', 'redis', 'mysql_test').run('uname -s') Linux Linux Linux In [8]: for connection, result in results.items(): ...: print("{0.host}: {1.stdout}".format(connection, result)) ...: ...: 47.104.148.xx: Linux 116.62.195.xx: Linux 47.99.123.xx: Linux
集成到一起：
from fabric import SerialGroup as Group def upload_and_unpack(c): if c.run('test -f /opt/mydata/myfile', warn=True).failed: c.put('myfiles.tgz', '/opt/mydata') c.run('tar -C /opt/mydata -xzvf /opt/mydata/myfiles.tgz') for connection in Group('web1', 'web2', 'web3'): upload_and_unpack(connection)
fabric 命令行工具
fabric提供了一个类似Shell终端的工具：fab
fab执行命令时，默认引用一个名称为fabfile.py的文件，这个文件包含一个到多个函数，使用fab命令可以调用这些函数， 函数在fabric中成为task
下面给出fabfile.py的样例文件：
from fabric import task @task def hostname(c): c.run('hostname') @task def ls(path='.'): c.run('ls {}'.format(path)) def tail(path='/etc/passwd', line=10): sudo('tail -n {0}, {1}'.format(line, path))
注意： 新版本的fab取消了api，所以相应的方法较之旧版本使用起来更加简洁，许多方法较之以前变化较大
[root@ykyk python_linux_automation]# fab3 --list
Available tasks:
hostname
ls
获取服务器信息需要在命令行指定：
[root@ykyk python_linux_automation]# fab3 -H mysql_test hostname izbp1cmbkj49ynx81cezu3z [root@ykyk python_linux_automation]# fab3 -H mysql_test,own,redis hostname izbp1cmbkj49ynx81cezu3z ykyk izbp1a43b9q4zlsifma7muz
fab命令行参数：
[root@ykyk python_linux_automation]# fab3 --help Usage: fab3 [--core-opts] task1 [--task1-opts] ... taskN [--taskN-opts] Core options: --complete Print tab-completion candidates for given parse remainder. --hide=STRING Set default value of run()'s 'hide' kwarg. --no-dedupe Disable task deduplication. --print-completion-script=STRING Print the tab-completion script for your preferred shell (bash|zsh|fish). --prompt-for-login-password Request an upfront SSH-auth password prompt. --prompt-for-passphrase Request an upfront SSH key passphrase prompt. --prompt-for-sudo-password Prompt user at start of session for the sudo.password config value. --write-pyc Enable creation of .pyc files. -c STRING, --collection=STRING Specify collection name to load. -d, --debug Enable debug output. -D INT, --list-depth=INT When listing tasks, only show the first INT levels. -e, --echo Echo executed commands before running. -f STRING, --config=STRING Runtime configuration file to use. -F STRING, --list-format=STRING Change the display format used when listing tasks. Should be one of: flat (default), nested, json. -h [STRING], --help[=STRING] Show core or per-task help and exit. -H STRING, --hosts=STRING Comma-separated host name(s) to execute tasks against. -i, --identity Path to runtime SSH identity (key) file. May be given multiple times. -l [STRING], --list[=STRING] List available tasks, optionally limited to a namespace. -p, --pty Use a pty when executing shell commands. -r STRING, --search-root=STRING Change root directory used for finding task modules. -S STRING, --ssh-config=STRING Path to runtime SSH config file. -V, --version Show version and exit. -w, --warn-only Warn, instead of failing, when shell commands fail.
- pty
pty用于设置伪终端，如果执行命令后需要一个常驻的服务进程，需要设置为pty=False,避免因fabric退出而导致程序退出
fabric装饰器
- fabric中的task
- task是fabric需要在远程服务器执行的任务，
- 默认情况下，fabfile中的所有可调用对象都是task，python中的函数是一个可调用对象
- 继承fabric的task类，不推荐
- 使用fabric装饰器，注意：如果fabfile中定义了多个task，只有其中一个使用了task，那么其他notask函数不是task
- role新版本取消了。使用SerialGroup
- runs_once 只运行一次
以上就是fabric的一些方法
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案例：使用fabric源码安装redis
from fabric import task from fabric import connection from invoke import Exit from invocations.console import confirm hosts = ['own'] @task#(hosts='own') def test(c): with c.prefix('cd /root/python_linux_automation/redis-4.0.9'): result = c.run('make && make test', warn=True, pty=False) if result.failed and not confirm('Tests failed, continue anyway?'): raise SystemExit("Aborting at user requeset") else: print('All tests passed without errors') c.run('make clean', warn=True, pty=False, hide=True) with c.prefix("cd /root/python_linux_automation/"): c.run('tar -czf redis-4.0.9.tar.gz redis-4.0.9') @task def deploy(c): c.put('redis-4.0.9.tar.gz', '/tmp/redis-4.0.9.tar.gz') with c.cd('/tmp'): c.run('tar xzf redis-4.0.9.tar.gz') with c.cd('redis-4.0.9'): c.run('make') with c.cd('src'): c.run('make install') @task def clean_file(c): with c.cd('/tmp'): c.run('rm -rf redis-4.0.9.tar.gz') c.run('rm -rf redis-4.0.9') @task def clean_local_file(c): with c.prefix('cd /root/python_linux_automation/'): c.run('rm -rf redis-4.0.9.tar.gz') @task def install(c): for host in hosts: c = connection.Connection('own') test(c) deploy(c) clean_file(c) clean_local_file(c)
Nothing is true,Nothing is fake.
