Python菜鸟之路:sqlalchemy/paramiko进阶

时间:2022-05-29 13:14:35

前言:ORM中的两种创建方式

  数据库优先:指的是先创建数据库,包括表和字段的建立,然后根据数据库生成ORM的代码,它是先创建数据库,再创建相关程序代码

  代码优先:就是先写代码,然后根据代码去生成数据库结构。

  代码优先创建数据库的本质:拿到类-->转换成table对象, 然后根据table对象生成sql语句--> 生成数据库表结构

 

SQLalchemy联表操作

一对多

# 表结构
class Group(Base): # 一对多的表,组中可能包含多个用户 __tablename__ = 'group' nid = Column(Integer, primary_key=True, autoincrement=True) caption = Column(String(32)) class User(Base): __tablename__ = 'user' uid = Column(Integer, primary_key=True, autoincrement=True) name = Column(String(32)) gid = Column(Integer, ForeignKey('group.nid'))
Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
# 创建完表之后,建立连接
Session = sessionmaker(bind=engine)
session = Session()

新增Group表数据
session.add_all([
    Group(caption='DBA'),
    Group(caption='SA'),
    ]
)
session.commit()
session.add(Group(caption='QA'))
新建User表数据
session.add_all([
    User(name='Bob', gid=1),
    User(name='Boss', gid=2),
    ]
)
session.commit()
user表和group表中插入数据

  上边的代码中,定义了2个表,一个是“组”,一个是“用户表”。一对多表示:一个组中可能存在多个用户。那么,需求来了,我想要查找出用户表中每个用户对应的组。

常规的联表查询如下:

ret = session.query(User.name, Group.caption).join(Group).all()
print(ret)  # join默认是进行left join
out: [('Bob', 'DBA'), ('Boss', 'SA')]

  虽然这样也查询到结果了。但是感觉还是很复杂,那有没有更加简便的方式呢!有,SQLalchemy中为我们提供了relationship类,来帮助我们应对一对多以及多对多的这种复杂表结构。还是以上边的需求为例,用relationship的话,代码如下:

  步骤一:需要在创建表的时候建立关系:在创建User表的时候,新增一种虚拟字段类型(数据库中并不真实存在) --> group = relationship("Group")

# 使用relationship,先必须在创建表的时候建立关系
class Group(Base):
    __tablename__ = 'group'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    caption = Column(String(32))

class User(Base):
    __tablename__ = 'user'
    uid = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String(32))
    gid = Column(Integer, ForeignKey('group.nid'))
    # 仅仅方便查询.
    group = relationship("Group")

  步骤二:开始查询之“正向查询

ret = session.query(User).all()
for obj in ret:
    # obj 代指user表中的每一行数据,是User对象
    # obj.group代指group对象,可以用obj.group.XXX来获取group表中的字段的值
    print(obj.uid, obj.name, obj.gid, obj.group, obj.group.nid, obj.group.caption)


out: # 1 Bob 1 <__main__.Group object at 0x0000000003B31438> 1 DBA
     # 2 Boss 2 <__main__.Group object at 0x0000000003B315F8> 2 SA

  可以看出,使用了非常简单的查询就将数据全部取了出来。细心的同学可能已经发现,上边写到了正向查询,那么有没有“反向查询”呢?有!

  反向查询需要在创建关系的时候,新增一个字段设置backref

group = relationship("Group", backref='uuu')

  查询语句就变为了:

obj = session.query(Group).filter(Group.caption=='DBA').first() 带有筛选条件的语句,筛选DBA组所有成员


print(obj) # obj表示符合条件的Group对象

out: <__main__.Group object at 0x00000000032EB710>
print(obj.uuu) # obj.uuu 就是符合筛选条件的User对象 out: [<__main__.User object at 0x0000000003B15400>, <__main__.User object at 0x0000000003B15470>] for i in obj.uuu:# obj.uuu需要用for循环来查询结果 print(i.uid, i.name, i.gid) out: 1 Bob 1 2 Boss 2

小结:

relationship()函数:这个函数告诉ORM,通过使用user.Group,Group类应该和User类连接起来
relationship()使用外键明确这两张表的关系。决定User.group属性是多对一的,即多个用户可以在同一个组里。
relationship()的子函数backref()提供表达反向关系的细节:relationship()对象的集合被Group.uuu引用。多对一的反向关系总是一对多,即一个组可以包含多个用户

多对多  

  上边的内容介绍了一对多的情况,生产环境中,也经常遇到多对多的情况。比如这样一种情形:某公司有好多服务器,员工也很多,业务交错在这些服务器上,就会造成一种现象:某台机器,多个人的业务在上边部署,这多个人具有这台服务器的权限。而对于每个人来说,他的业务不仅仅需要一台服务器,有时会部署在多台服务器。这样的情形,就构成了多对对的情况,即:单台服务器被多人拥有,单人拥有多台服务器的权限。这时候需要额外的一张表,来专门存储主机与用户之间的对应关系。三张表结构如下:

class Host(Base):
    __tablename__ = 'host'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    hostname = Column(String(32))
    port = Column(String(32))
    ip = Column(String(32))

class HostUser(Base):
    __tablename__ = 'host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))

# 多对多
class HostToHostUser(Base):
    __tablename__ = 'host_to_host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)

    # 两个关联的id,以外键的形式存在
    host_id = Column(Integer, ForeignKey('host.nid'))
    host_user_id = Column(Integer, ForeignKey('host_user.nid'))
Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
# 创建完表之后,建立连接
Session = sessionmaker(bind=engine)
session = Session()
# 新增表数据
session.add_all([
    Host(hostname='c1',port='22',ip='1.1.1.1'),
    Host(hostname='c2',port='22',ip='1.1.1.2'),
    Host(hostname='c3',port='22',ip='1.1.1.3'),
    Host(hostname='c4',port='22',ip='1.1.1.4'),
    Host(hostname='c5',port='22',ip='1.1.1.5'),
])
session.commit()

session.add_all([
    HostUser(username='root'),
    HostUser(username='db'),
    HostUser(username='nb'),
    HostUser(username='sb'),
])
session.commit()

session.add_all([
    HostToHostUser(host_id=1,host_user_id=1),
    HostToHostUser(host_id=1,host_user_id=2),
    HostToHostUser(host_id=1,host_user_id=3),
    HostToHostUser(host_id=2,host_user_id=2),
    HostToHostUser(host_id=2,host_user_id=4),
    HostToHostUser(host_id=2,host_user_id=3),
])
session.commit()
新增表数据

  上边增加的数据,增加了五台服务器,分别是c1,c2,c3,c4,c5。对应ID:1,2,3,4,5。

          增加了四个人,分别是root, db, nb, sb,对应ID:1,2,3,4

          关系表中 用户与主机的对应关系:

            Python菜鸟之路:sqlalchemy/paramiko进阶

  那么,需求来了:获取拥有主机1权限的所有用户。

  在没有用到relationship时,查询方式如下:

# 1. 获取主机为c1的对象
host_obj = session.query(Host).filter(Host.hostname == 'c1').first()

# 2. 获取查询关系表中拥有主机c1的用户ID
host_2_host_user = session.query(HostToHostUser.host_user_id).filter(HostToHostUser.host_id == host_obj.nid).all()
print(host_2_host_user) # [(1,), (2,), (3,)]

r = zip(*host_2_host_user)
print(list(r)) #[(1, 2, 3)] 这就是用户ID列表
# 3. 根据用户ID列表,查询用户名
users = session.query(HostUser.username).filter(HostUser.nid.in_(list(r)[0])).all()
print(users) # [('root',), ('db',), ('nb',)]

  可以看出,用普通方法查询,非常的繁琐,实际上进行了3次sql查询。那么使用relationship的话,会有哪些改变?

  步骤1:创建关系表-->在创建表的时候,创建关系

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
class Host(Base):
    __tablename__ = 'host'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    hostname = Column(String(32))
    port = Column(String(32))
    ip = Column(String(32))

class HostUser(Base):
    __tablename__ = 'host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))

# 多对多
class HostToHostUser(Base):
    __tablename__ = 'host_to_host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)

    host_id = Column(Integer, ForeignKey('host.nid'))
    host_user_id = Column(Integer, ForeignKey('host_user.nid'))

    # 新写法中有用
    host = relationship('Host', backref='h')
    host_user = relationship('HostUser', backref='u')
带有关系的三张表

  步骤2:反向查找Host,从Host表中获取到HostToHostUser表中的字段信息

host_obj = session.query(Host).filter(Host.hostname == 'c1').first()
print(host_obj) # <__main__.Host object at 0x0000000003C11128> print(host_obj.hostname) # 主机名:c1 print(host_obj.h) # host_obj.h表示HostToHostUser表中,符合筛选条件的HostToHostUser数据对象列表 [<__main__.HostToHostUser object at 0x0000000003B3F198>, <__main__.HostToHostUser object at 0x0000000003B3F898>, <__main__.HostToHostUser object at 0x0000000003B3F908>] # 循环获取用户信息 for item in host_obj.h: # print(item.host_user) # 一行用户的数据, HostUser 表的一行数据对象 print(item.host_user.username) # root db nb

  可以看出,使用relationship,整个查询使用一个sql就搞定了。接下来介绍另外一种方式,和之前的差异也是在创建表的时候,具体看如下代码:

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
class HostToHostUser(Base):
    __tablename__ = 'host_to_host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)

    host_id = Column(Integer, ForeignKey('host.nid'))
    host_user_id = Column(Integer, ForeignKey('host_user.nid'))

class Host(Base):
    __tablename__ = 'host'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    hostname = Column(String(32))
    port = Column(String(32))
    ip = Column(String(32))
    # 新的书写方式,不需要在多对多表中建立关系
    host_user = relationship('HostUser', secondary=HostToHostUser.__table__, backref='h')

class HostUser(Base):
    __tablename__ = 'host_user'
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))
新方式创建表关系
# 创建完表之后,建立连接
Session = sessionmaker(bind=engine)
session = Session()

# 步骤1: 获取主机名为c1的Host对象
host_obj = session.query(Host).filter(Host.hostname=='c1').first()

# 步骤2: 通过Host对象,正向查找用户名
print(host_obj.host_user) # [<__main__.HostUser object at 0x0000000003BA1DA0>, <__main__.HostUser object at 0x0000000003BA1E10>, <__main__.HostUser object at 0x0000000003BA1E80>]
for i in host_obj.host_user:
    print(i.username)

out:root db nb

关于filter和filter_by

  用法不同而已,filter 可以像写 sql 的 where 条件那样写 > < 等条件,但引用列名时,需要通过 类名.属性名 的方式,引用列值时使用'=='

  filter_by 可以使用 python 的正常参数传递方法传递条件,指定列名时,不需要额外指定类名。,参数名对应名类中的属性名,但似乎不能使用 > < 等条件。

小结:

SQLalchemy联表操作的方式
方式1:使用普通方法:join,多次查询符合筛选条件的数据
方式2:relationshi关系 --》ORM提供的一种便捷查询方法。使用relationship可以方便的实现一对多,以及多对多的查询
  一对多关系:
  一般情况下:fk与关系放在一起
  多对多关系:多一张表,用来存放fk,完成查询需求时有两种方法
    方法1、将关系放到关系表中 --》既有正向也有反向
    方法2、在某一张表中放关系 --》只有正向

paramiko-基础

  paramiko的两种基本用法:基于用户名密码连接、基于公钥私钥连接。主要有两个大类:SSHClient(用于连接远程服务器并执行基本命令)、SFTPClient(用于连接远程服务器并执行上传下载)

SSHClient

基于用户名密码连接:

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko

# 创建SSH对象
ssh = paramiko.SSHClient()
# 允许连接不在know_hosts文件中的主机
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
# 连接服务器
ssh.connect(hostname='172.25.50.13', port=22, username='work', password='123456')

# 执行命令
stdin, stdout, stderr = ssh.exec_command('ls -l')
# 获取命令结果
result = stdout.read()
print(result.decode())
# 关闭连接
ssh.close()
out: 
total 8
drwxr-xr-x 2 work work 4096 Mar 18 19:22 cn_market_lua
drwxrwxr-x 3 work work 4096 Mar 18 19:09 www
基于用户名密码实现执行命令

基于公钥密钥连接:

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko

# 创建key文件
private_key = paramiko.RSAKey.from_private_key_file('/home/auto/.ssh/id_rsa')

# 创建SSH对象
ssh = paramiko.SSHClient()
# 允许连接不在know_hosts文件中的主机
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
# 连接服务器
ssh.connect(hostname='172.25.50.13', port=22, username='work', key=private_key)

# 执行命令
stdin, stdout, stderr = ssh.exec_command('df -h')
# 获取命令结果
result = stdout.read()

# 关闭连接
ssh.close()
out:
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        20G  4.2G   15G  23% /
tmpfs           1.9G     0  1.9G   0% /dev/shm
/dev/vdb1        99G  499M   93G   1% /data0
基于公钥私钥实现远程执行命令

SFTPClient

基于用户名密码连接:

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko

# 创建transport
transport = paramiko.Transport(('172.25.50.13',22))
transport.connect(username='work',password='123456')

# 创建sftpclient,并基于transport连接,把他俩进行绑定
sftp = paramiko.SFTPClient.from_transport(transport)
# 将location.py 上传至服务器 /tmp/test.py
sftp.put('/tmp/location.py', '/tmp/test.py')
# 将remove_path 下载到本地 local_path
sftp.get('remove_path', 'local_path')

# 关闭session
transport.close()
基于用户名密码实现上传下载

基于公钥密钥连接:

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko
# 创建key文件
private_key = paramiko.RSAKey.from_private_key_file('/home/auto/.ssh/id_rsa')

transport = paramiko.Transport(('172.25.50.13', 22))
transport.connect(username='work', pkey=private_key )

sftp = paramiko.SFTPClient.from_transport(transport)
# 将location.py 上传至服务器 /tmp/test.py
sftp.put('/tmp/location.py', '/tmp/test.py')
# 将remove_path 下载到本地 local_path
sftp.get('remove_path', 'local_path')

transport.close()
基于公钥密钥上传下载

Paramiko进阶

  从基础环节,我们学到了基本的使用方法。现在来看下源代码中这块的执行

  第一步:创建SSHclient对象,这部没啥说的,关注一个初始化字段self._transport=None

ssh = paramiko.SSHClient()

  第二步:连接到SSH主机,完成认证

ssh.connect(hostname='172.25.50.13', port=22, username='work', password='123456')

  这步到底做了什么呢?看下源代码

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
    def connect(
        self,
        hostname,
        port=SSH_PORT,
        username=None,
        password=None,
        pkey=None,
        key_filename=None,
        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
    ):
        """
        Connect to an SSH server and authenticate to it.  The server's host key
        is checked against the system host keys (see `load_system_host_keys`)
        and any local host keys (`load_host_keys`).  If the server's hostname
        is not found in either set of host keys, the missing host key policy
        is used (see `set_missing_host_key_policy`).  The default policy is
        to reject the key and raise an `.SSHException`.

        Authentication is attempted in the following order of priority:

            - The ``pkey`` or ``key_filename`` passed in (if any)
            - Any key we can find through an SSH agent
            - Any "id_rsa", "id_dsa" or "id_ecdsa" key discoverable in
              ``~/.ssh/``
            - Plain username/password auth, if a password was given

        If a private key requires a password to unlock it, and a password is
        passed in, that password will be used to attempt to unlock the key.

        :param str hostname: the server to connect to
        :param int port: the server port to connect to
        :param str username:
            the username to authenticate as (defaults to the current local
            username)
        :param str password:
            a password to use for authentication or for unlocking a private key
        :param .PKey pkey: an optional private key to use for authentication
        :param str key_filename:
            the filename, or list of filenames, of optional private key(s) to
            try for authentication
        :param float timeout:
            an optional timeout (in seconds) for the TCP connect
        :param bool allow_agent:
            set to False to disable connecting to the SSH agent
        :param bool look_for_keys:
            set to False to disable searching for discoverable private key
            files in ``~/.ssh/``
        :param bool compress: set to True to turn on compression
        :param socket sock:
            an open socket or socket-like object (such as a `.Channel`) to use
            for communication to the target host
        :param bool gss_auth:
            ``True`` if you want to use GSS-API authentication
        :param bool gss_kex:
            Perform GSS-API Key Exchange and user authentication
        :param bool gss_deleg_creds: Delegate GSS-API client credentials or not
        :param str gss_host:
            The targets name in the kerberos database. default: hostname
        :param float banner_timeout: an optional timeout (in seconds) to wait
            for the SSH banner to be presented.

        :raises BadHostKeyException: if the server's host key could not be
            verified
        :raises AuthenticationException: if authentication failed
        :raises SSHException: if there was any other error connecting or
            establishing an SSH session
        :raises socket.error: if a socket error occurred while connecting

        .. versionchanged:: 1.15
            Added the ``banner_timeout``, ``gss_auth``, ``gss_kex``,
            ``gss_deleg_creds`` and ``gss_host`` arguments.
        """
        if not sock:
            errors = {}
            # Try multiple possible address families (e.g. IPv4 vs IPv6)
            to_try = list(self._families_and_addresses(hostname, port))
            for af, addr in to_try:
                try:
                    sock = socket.socket(af, socket.SOCK_STREAM)
                    if timeout is not None:
                        try:
                            sock.settimeout(timeout)
                        except:
                            pass
                    retry_on_signal(lambda: sock.connect(addr))
                    # Break out of the loop on success
                    break
                except socket.error as e:
                    # Raise anything that isn't a straight up connection error
                    # (such as a resolution error)
                    if e.errno not in (ECONNREFUSED, EHOSTUNREACH):
                        raise
                    # Capture anything else so we know how the run looks once
                    # iteration is complete. Retain info about which attempt
                    # this was.
                    errors[addr] = e

            # Make sure we explode usefully if no address family attempts
            # succeeded. We've no way of knowing which error is the "right"
            # one, so we construct a hybrid exception containing all the real
            # ones, of a subclass that client code should still be watching for
            # (socket.error)
            if len(errors) == len(to_try):
                raise NoValidConnectionsError(errors)

        t = self._transport = Transport(sock, gss_kex=gss_kex, gss_deleg_creds=gss_deleg_creds)
        t.use_compression(compress=compress)
        if gss_kex and gss_host is None:
            t.set_gss_host(hostname)
        elif gss_kex and gss_host is not None:
            t.set_gss_host(gss_host)
        else:
            pass
        if self._log_channel is not None:
            t.set_log_channel(self._log_channel)
        if banner_timeout is not None:
            t.banner_timeout = banner_timeout
        t.start_client()
        ResourceManager.register(self, t)

        server_key = t.get_remote_server_key()
        keytype = server_key.get_name()

        if port == SSH_PORT:
            server_hostkey_name = hostname
        else:
            server_hostkey_name = "[%s]:%d" % (hostname, port)

        # If GSS-API Key Exchange is performed we are not required to check the
        # host key, because the host is authenticated via GSS-API / SSPI as
        # well as our client.
        if not self._transport.use_gss_kex:
            our_server_key = self._system_host_keys.get(server_hostkey_name,
                                                         {}).get(keytype, None)
            if our_server_key is None:
                our_server_key = self._host_keys.get(server_hostkey_name,
                                                     {}).get(keytype, None)
            if our_server_key is None:
                # will raise exception if the key is rejected; let that fall out
                self._policy.missing_host_key(self, server_hostkey_name,
                                              server_key)
                # if the callback returns, assume the key is ok
                our_server_key = server_key

            if server_key != our_server_key:
                raise BadHostKeyException(hostname, server_key, our_server_key)

        if username is None:
            username = getpass.getuser()

        if key_filename is None:
            key_filenames = []
        elif isinstance(key_filename, string_types):
            key_filenames = [key_filename]
        else:
            key_filenames = key_filename
        if gss_host is None:
            gss_host = hostname
        self._auth(username, password, pkey, key_filenames, allow_agent,
                   look_for_keys, gss_auth, gss_kex, gss_deleg_creds, gss_host)
SSHClient.connect源码部分

  最关键的一步:t = self._transport = Transport(sock, gss_kex=gss_kex, gss_deleg_creds=gss_deleg_creds)

  这步源码中说明如下:

  Create a new SSH session over an existing socket, or socket-like
        object.  This only creates the `.Transport` object; it doesn't begin the
        SSH session yet.  Use `connect` or `start_client` to begin a client
        session, or `start_server` to begin a server session.

  那么可以看出,实际上是这句只是创建了一个session,或者是socket-like的对象。且这个session并没有启动,只有在调用connect或者start_client方法时,session才会生效。

   那么,我们是否也可以自己封装一个tranport来定制一些功能呢?

  还是以基础中的案例,现在就定制一个基于用户名密码的transport

  步骤1:创建一个transport

# 创建transport
transport = paramiko.Transport(('172.25.50.13', 22))

  步骤2:调用connect方法启动session

# 调用connect方法启动session
transport.connect(username='work', password='123456')

  步骤3:覆盖原SSHClient对象对于self._transport的定义

ssh = paramiko.SSHClient()
ssh._transport = transport

  步骤4:执行命令,执行完毕后关闭session

stdin, stdout, stderr = ssh.exec_command('df -h')
print(stdout.read().decode())

transport.close()
Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko
# 创建transport
transport = paramiko.Transport(('172.25.50.13', 22))
# 调用connect方法启动session
transport.connect(username='work', password='123456')

ssh = paramiko.SSHClient()
ssh._transport = transport

stdin, stdout, stderr = ssh.exec_command('df -h')
print(stdout.read().decode())

transport.close()
完整代码-定制transport实现基于用户名密码执行命令
Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko

private_key = paramiko.RSAKey.from_private_key_file('/home/auto/.ssh/id_rsa')

transport = paramiko.Transport(('172.25.50.13', 22))
transport.connect(username='work', pkey=private_key)

ssh = paramiko.SSHClient()
ssh._transport = transport

stdin, stdout, stderr = ssh.exec_command('df')

print(stdout.read().decode())

transport.close()
完整代码-定制transport实现基于ssh-key执行命令

  

  那么,现在需求又来了。我不仅要实现单纯的执行命令,还要在执行命令之后,上传一个文件,上传文件之后依然能执行命令。

  像这样一个复杂的需求,就需要我们自己来封装一个SSHclient,本质上也是对self._transport进行重新封装

# 自己封装一个类似SSHClient的类
import paramiko

class SSHConnection(object):
    def __init__(self, host='172.25.50.13', port=22, username='work',pwd='123456'):
        self.host = host
        self.port = port
        self.username = username
        self.pwd = pwd
        self.__k = None

    def run(self):
        self.connect()
        pass
        self.close()

    def connect(self):
        # 创建transport
        transport = paramiko.Transport((self.host,self.port))
        # 启动session
        transport.connect(username=self.username,password=self.pwd)
        self.__transport = transport

    def close(self):
        self.__transport.close()

    def cmd(self, command):
        ssh = paramiko.SSHClient()
        ssh._transport = self.__transport
        # 执行命令
        stdin, stdout, stderr = ssh.exec_command(command)
        # 获取命令结果
        result = stdout.read()
        return result

    def upload(self,local_path, target_path):
        # 连接,上传
        sftp = paramiko.SFTPClient.from_transport(self.__transport)
        # 将location.py 上传至服务器 /tmp/test.py
        sftp.put(local_path, target_path)

ssh = SSHConnection()
ssh.connect()
# 执行命令
r1 = ssh.cmd('df')
print(r1.decode())
# 上传文件
ssh.upload('s2.py', "/home/alex/s7.py")

ssh.close()

堡垒机  

       Python菜鸟之路:sqlalchemy/paramiko进阶

  上图是一个基本的堡垒机模型,大概就是:

  • 管理员为用户在服务器上创建账号(将公钥放置服务器,或者使用用户名密码)
  • 用户登陆堡垒机,输入堡垒机用户名密码,显示当前用户管理的服务器列表
  • 用户选择服务器,并自动登陆
  • 执行操作并同时记录用户操作

 使用paramiko就可以实现上述功能,这里先省略数据库方面:

版本一: 1)用户在终端输入内容,并将内容发送至远程服务器, 

     2)远程服务器执行命令,并将结果返回

     3)用户终端显示内容

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
import paramiko
import sys
import os
import socket
import select
import getpass
from paramiko.py3compat import u  # py27中注释掉这行


tran = paramiko.Transport(('172.25.50.13', 22,))
tran.start_client()
tran.auth_password('work', '123456')

# 打开一个通道
chan = tran.open_session()
# 获取一个终端
chan.get_pty()
# 激活器
chan.invoke_shell()

while True:
    # 监视用户输入和服务器返回数据
    # sys.stdin 处理用户输入
    # chan 是之前创建的通道,用于接收服务器返回信息
    readable, writeable, error = select.select([chan, sys.stdin, ],[],[],1)
    if chan in readable:
        try:
            x = u(chan.recv(1024)) # py3中 代码
            # x = chan.recv(1024)   # py2中代码
            if len(x) == 0:
                print('\r\n*** EOF\r\n')
                break
            sys.stdout.write(x)
            sys.stdout.flush()
        except socket.timeout:
            pass
    if sys.stdin in readable:
        inp = sys.stdin.readline()
        chan.sendall(inp)

chan.close()
tran.close()
版本1

版本二:在版本一中,可以发现和真是的shell环境是有区别的,不支持补全,非常难用。那么版本二就可以完成tab补全等功能,和真是shell一样。

    核心要点:用户每次输入1个字符,就立即发送到服务端。然后在client端接收服务端的返回

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
# 肆意妄为 2 版本  改变终端模式,每输入一个字符,立即发送
import paramiko
import sys
import os
import socket
import select
import getpass
import termios # windows中没有这个模块
import tty
from paramiko.py3compat import u  # py2 中需要注释掉这行

tran = paramiko.Transport(('172.25.50.13', 22,))
tran.start_client()
tran.auth_password('work', '123456')

# 打开一个通道
chan = tran.open_session()
# 获取一个终端
chan.get_pty()
# 激活器
chan.invoke_shell()


# 获取原tty属性
oldtty = termios.tcgetattr(sys.stdin)
try:
    # 为tty设置新属性
    # 默认当前tty设备属性:
    #   输入一行回车,执行
    #   CTRL+C 进程退出,遇到特殊字符,特殊处理。

    # 这是为原始模式,不认识所有特殊符号
    # 放置特殊字符应用在当前终端,如此设置,将所有的用户输入均发送到远程服务器
    tty.setraw(sys.stdin.fileno())
    chan.settimeout(0.0)

    while True:
        # 监视 用户输入 和 远程服务器返回数据(socket)
        # 阻塞,直到句柄可读
        r, w, e = select.select([chan, sys.stdin], [], [], 1)
        if chan in r:
            try:
                # x = u(chan.recv(1024))  # py2中需要修改
                x = chan.recv(1024)
                if len(x) == 0:
                    print('\r\n*** EOF\r\n')
                    break
                sys.stdout.write(x)
                sys.stdout.flush()
            except socket.timeout:
                pass
        if sys.stdin in r:
            x = sys.stdin.read(1)
            if len(x) == 0:
                break
            chan.send(x)

finally:
    # 重新设置终端属性
    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, oldtty)


chan.close()
tran.close()
版本二

    版本二种,实现了一个shell的完善环境。但是实际生产中,还有一个很重要的环节“用户验证”。版本1和版本2中,并不具备这个功能,现在来看版本3

版本三:带有用户验证功能的堡垒机

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
# 不带日志版

import paramiko
import sys
import os
import socket
import getpass

from paramiko.py3compat import u

# windows does not have termios...
try:
    import termios
    import tty
    has_termios = True
except ImportError:
    has_termios = False


def interactive_shell(chan):
    if has_termios:
        posix_shell(chan)
    else:
        windows_shell(chan)


def posix_shell(chan):
    import select

    oldtty = termios.tcgetattr(sys.stdin)
    try:
        tty.setraw(sys.stdin.fileno())
        tty.setcbreak(sys.stdin.fileno())
        chan.settimeout(0.0)

        flag = False
        temp_list = []
        while True:
            r, w, e = select.select([chan, sys.stdin], [], [])
            if chan in r:
                try:
                    x = u(chan.recv(1024))
                    if len(x) == 0:
                        sys.stdout.write('\r\n*** EOF\r\n')
                        break
                    sys.stdout.write(x)
                    sys.stdout.flush()
                except socket.timeout:
                    pass
            if sys.stdin in r:
                x = sys.stdin.read(1)
                import json

                if len(x) == 0:
                    break
                chan.send(x)

    finally:
        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, oldtty)


def windows_shell(chan):
    import threading

    sys.stdout.write("Line-buffered terminal emulation. Press F6 or ^Z to send EOF.\r\n\r\n")

    def writeall(sock):
        while True:
            data = sock.recv(256)
            if not data:
                sys.stdout.write('\r\n*** EOF ***\r\n\r\n')
                sys.stdout.flush()
                break
            sys.stdout.write(data)
            sys.stdout.flush()

    writer = threading.Thread(target=writeall, args=(chan,))
    writer.start()

    try:
        while True:
            d = sys.stdin.read(1)
            if not d:
                break
            chan.send(d)
    except EOFError:
        # user hit ^Z or F6
        pass


def run():
    # 获取当前登录用户
    username = raw_input('Username ')
    hostname = raw_input('Hostname: ')
    pwd = raw_input('password: ')

    tran = paramiko.Transport((hostname, 22,))
    tran.start_client()
    tran.auth_password(username, pwd)

    # 打开一个通道
    chan = tran.open_session()
    # 获取一个终端
    chan.get_pty()
    # 激活器
    chan.invoke_shell()

    interactive_shell(chan)

    chan.close()
    tran.close()


if __name__ == '__main__':
    run()
版本三

   版本三在不考虑数据库的情况下,其实已经相对完善了。但是堡垒机还得有一个必要的功能,“记录用户操作日志

 终极版本:带有用户日志的堡垒机

Python菜鸟之路:sqlalchemy/paramiko进阶Python菜鸟之路:sqlalchemy/paramiko进阶
# 记录用户日志
import paramiko
import sys
import os
import socket
import getpass

from paramiko.py3compat import u

# windows does not have termios...
try:
    import termios
    import tty
    has_termios = True
except ImportError:
    has_termios = False


def interactive_shell(chan):
    if has_termios:
        posix_shell(chan)
    else:
        windows_shell(chan)


def posix_shell(chan):
    import select

    oldtty = termios.tcgetattr(sys.stdin)
    try:
        tty.setraw(sys.stdin.fileno())
        tty.setcbreak(sys.stdin.fileno())
        chan.settimeout(0.0)
        log = open('handle.log', 'a+', encoding='utf-8')
        flag = False
        temp_list = []
        while True:
            r, w, e = select.select([chan, sys.stdin], [], [])
            if chan in r:
                try:
                    x = u(chan.recv(1024))
                    if len(x) == 0:
                        sys.stdout.write('\r\n*** EOF\r\n')
                        break
                    if flag:
                        if x.startswith('\r\n'):
                            pass
                        else:
                            temp_list.append(x)
                        flag = False
                    sys.stdout.write(x)
                    sys.stdout.flush()
                except socket.timeout:
                    pass
            if sys.stdin in r:
                x = sys.stdin.read(1)
                import json

                if len(x) == 0:
                    break

                if x == '\t':
                    flag = True
                else:
                    temp_list.append(x)
                if x == '\r':
                    log.write(''.join(temp_list))
                    log.flush()
                    temp_list.clear()
                chan.send(x)

    finally:
        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, oldtty)


def windows_shell(chan):
    import threading

    sys.stdout.write("Line-buffered terminal emulation. Press F6 or ^Z to send EOF.\r\n\r\n")

    def writeall(sock):
        while True:
            data = sock.recv(256)
            if not data:
                sys.stdout.write('\r\n*** EOF ***\r\n\r\n')
                sys.stdout.flush()
                break
            sys.stdout.write(data)
            sys.stdout.flush()

    writer = threading.Thread(target=writeall, args=(chan,))
    writer.start()

    try:
        while True:
            d = sys.stdin.read(1)
            if not d:
                break
            chan.send(d)
    except EOFError:
        # user hit ^Z or F6
        pass


def run():
    default_username = getpass.getuser()
    username = input('Username [%s]: ' % default_username)
    if len(username) == 0:
        username = default_username


    hostname = input('Hostname: ')
    if len(hostname) == 0:
        print('*** Hostname required.')
        sys.exit(1)

    tran = paramiko.Transport((hostname, 22,))
    tran.start_client()

    default_auth = "p"
    auth = input('Auth by (p)assword or (r)sa key[%s] ' % default_auth)
    if len(auth) == 0:
        auth = default_auth

    if auth == 'r':
        default_path = os.path.join(os.environ['HOME'], '.ssh', 'id_rsa')
        path = input('RSA key [%s]: ' % default_path)
        if len(path) == 0:
            path = default_path
        try:
            key = paramiko.RSAKey.from_private_key_file(path)
        except paramiko.PasswordRequiredException:
            password = getpass.getpass('RSA key password: ')
            key = paramiko.RSAKey.from_private_key_file(path, password)
        tran.auth_publickey(username, key)
    else:
        pw = getpass.getpass('Password for %s@%s: ' % (username, hostname))
        tran.auth_password(username, pw)

    # 打开一个通道
    chan = tran.open_session()
    # 获取一个终端
    chan.get_pty()
    # 激活器
    chan.invoke_shell()

    interactive_shell(chan)

    chan.close()
    tran.close()


if __name__ == '__main__':
    run()
终极版-Python3执行