如何设置 pexpect ssh 会话的列宽? [英] How do I set the column width of a pexpect ssh session?
问题描述
我正在编写一个简单的 python 脚本来通过 SSH 连接到 SAN，运行一组命令.最终，每个命令都将与时间戳一起记录到单独的日志中，然后退出.这是因为我们要连接的设备不支持证书 ssh 连接，并且在其当前固件版本上没有不错的日志记录功能.
I am writing a simple python script to connect to a SAN via SSH, run a set of commands. Ultimately each command will be logged to a separate log along with a timestamp, and then exit. This is because the device we are connecting to doesn't support certificate ssh connections, and doesn't have decent logging capabilities on its current firmware revision.
我似乎遇到的问题是创建的 SSH 会话似乎限制为 78 个字符宽.每个命令生成的结果明显更宽 - 155 个字符.这引起了一堆时髦.
The issue that I seem to be running into is that the SSH session that is created seems to be limited to 78 characters wide. The results generated from each command are significantly wider - 155 characters. This is causing a bunch of funkiness.
首先，当前状态下的结果明显更难以解析.其次，由于缓冲区明显较小，最终的音量命令将无法正确执行，因为 pexpect 启动的 SSH 会话实际上会提示按任意键继续".
First, the results in their current state are significantly more difficult to parse. Second, because the buffer is significantly smaller, the final volume command won't execute properly because the pexpect launched SSH session actually gets prompted to "press any key to continue".
如何更改 pexpect 会话的列宽?
How do I change the column width of the pexpect session?
这是当前代码(它可以工作但不完整):
Here is the current code (it works but is incomplete):
#!/usr/bin/python
import pexpect
import os
PASS='mypassword'
HOST='1.2.3.4'
LOGIN_COMMAND='ssh manage@'+HOST
CTL_COMMAND='show controller-statistics'
VDISK_COMMAND='show vdisk-statistics'
VOL_COMMAND='show volume-statistics'
VDISK_LOG='vdisk.log'
VOLUME_LOG='volume.log'
CONTROLLER_LOG='volume.log'
DATE=os.system('date +%Y%m%d%H%M%S')
child=pexpect.spawn(LOGIN_COMMAND)
child.setecho(True)
child.logfile = open('FetchSan.log','w+')
child.expect('Password: ')
child.sendline(PASS)
child.expect('# ')
child.sendline(CTL_COMMAND)
print child.before
child.expect('# ')
child.sendline(VDISK_COMMAND)
print child.before
child.expect('# ')
print "Sending "+VOL_COMMAND
child.sendline(VOL_COMMAND)
print child.before
child.expect('# ')
child.sendline('exit')
child.expect(pexpect.EOF)
print child.before
预期的输出:
# show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
---------------------------------------------------------------------------------------------------------------------------------------------------------
controller_A 0 45963169 1573.3KB 67 386769785 514179976 6687.8GB 5750.6GB
controller_B 20 45963088 4627.4KB 421 3208370173 587661282 63.9TB 5211.2GB
---------------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
------------------------------------------------------------------------------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0 45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2282.4KB 164 23229435 76509765 5506.7GB 1605.3GB
DATA1 00c0ff1311f3000087d8c44f00000000 2286.5KB 167 23490851 78314374 5519.0GB 1603.8GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0 26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 654.8KB 5 3049980 15317236 1187.3GB 1942.1GB
FRA1 00c0ff13349e000007d9c44f00000000 778.7KB 6 3016569 15234734 1179.3GB 1940.4GB
------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
Name Serial Number Bytes per second IOPS Number of Reads Number of Writes Data Read Data Written
-----------------------------------------------------------------------------------------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 14.8KB 5 239611146 107147564 1321.1GB 110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2402.8KB 218 1701488316 336678620 33.9TB 3184.6GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B 0 921 15 2273.7KB 2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2303.4KB 209 1506883611 250984824 30.0TB 2026.6GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 709.1KB 28 25123082 161710495 1891.0GB 2230.0GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 793.0KB 34 122052720 245322281 3475.7GB 3410.0GB
-----------------------------------------------------------------------------------------------------------------------------------------------------
Success: Command completed successfully.
打印到终端的输出(如前所述，第三个命令不会在当前状态下执行):
The output as printed to the terminal (as mentioned, the 3rd command won't execute in its current state):
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
Sending show volume-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
Traceback (most recent call last):
File "./fetchSAN.py", line 34, in <module>
child.expect('# ')
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 321, in expect
timeout, searchwindowsize, async)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/spawnbase.py", line 345, in expect_list
return exp.expect_loop(timeout)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 107, in expect_loop
return self.timeout(e)
File "/Library/Python/2.7/site-packages/pexpect-4.2.1-py2.7.egg/pexpect/expect.py", line 70, in timeout
raise TIMEOUT(msg)
pexpect.exceptions.TIMEOUT: Timeout exceeded.
<pexpect.pty_spawn.spawn object at 0x105333910>
command: /usr/bin/ssh
args: ['/usr/bin/ssh', 'manage@10.254.27.49']
buffer (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
before (last 100 chars): '-------------------------------------------------------------\r\nPress any key to continue (Q to quit)'
after: <class 'pexpect.exceptions.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 19519
child_fd: 5
closed: False
timeout: 30
delimiter: <class 'pexpect.exceptions.EOF'>
logfile: <open file 'FetchSan.log', mode 'w+' at 0x1053321e0>
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
searcher: searcher_re:
0: re.compile("# ")
这是日志中捕获的内容:
And here is what is captured in the log:
Password: mypassword
HP StorageWorks MSA Storage P2000 G3 FC
System Name: Uninitialized Name
System Location:Uninitialized Location
Version:TS230P008
# show controller-statistics
show controller-statistics
Durable ID CPU Load Power On Time (Secs) Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
controller_A 3 45962495 3803.1KB
73 386765821 514137947 6687.8GB
5748.9GB
controller_B 20 45962413 5000.7KB
415 3208317860 587434274 63.9TB
5208.8GB
----------------------------------------------------------------------
Success: Command completed successfully.
# show vdisk-statistics
show vdisk-statistics
Name Serial Number Bytes per second IOPS
Number of Reads Number of Writes Data Read Data Written
----------------------------------------------------------------------------
CRS 00c0ff13349e000006d5c44f00000000 0B 0
45861 26756 3233.0MB 106.2MB
DATA 00c0ff1311f300006dd7c44f00000000 2187.2KB 152
23220764 76411017 5506.3GB 1604.1GB
DATA1 00c0ff1311f3000087d8c44f00000000 2295.2KB 154
23481442 78215540 5518.5GB 1602.6GB
DATA2 00c0ff1311f30000c2f8ce5700000000 0B 0
26 4 1446.9KB 65.5KB
FRA 00c0ff13349e000001d8c44f00000000 1829.3KB 14
3049951 15310681 1187.3GB 1941.2GB
FRA1 00c0ff13349e000007d9c44f00000000 1872.8KB 14
3016521 15228157 1179.3GB 1939.5GB
----------------------------------------------------------------------------
Success: Command completed successfully.
# show volume-statistics
show volume-statistics
Name Serial Number Bytes per second
IOPS Number of Reads Number of Writes Data Read
Data Written
----------------------------------------------------------------------
CRS_v001 00c0ff13349e0000fdd6c44f01000000 11.7KB
5 239609039 107145979 1321.0GB
110.5GB
DATA1_v001 00c0ff1311f30000d0d8c44f01000000 2604.5KB
209 1701459941 336563041 33.9TB
3183.3GB
DATA2_v001 00c0ff1311f3000040f9ce5701000000 0B
0 921 15 2273.7KB
2114.0KB
DATA_v001 00c0ff1311f30000bdd7c44f01000000 2382.8KB
194 1506859273 250871273 30.0TB
2025.4GB
FRA1_v001 00c0ff13349e00001ed9c44f01000000 1923.5KB
31 25123006 161690520 1891.0GB
2229.1GB
FRA_v001 00c0ff13349e00001fd8c44f01000000 2008.5KB
37 122050872 245301514 3475.7GB
3409.1GB
----------------------------------------------------------------------
Press any key to continue (Q to quit)%
推荐答案
作为起点:根据手册，SAN 有一个禁用寻呼机的命令.请参阅set cli-parameters pager off 的文档.执行该命令可能就足够了.它可能还有一个命令来设置用于格式化输出的终端行和列，尽管我找不到.
As a starting point: According to the manual, that SAN has a command to disable the pager. See the documentation for set cli-parameters pager off. It may be sufficient to execute that command. It may also have a command to set the terminal rows and columns that it uses for formatting output, although I wasn't able to find one.
回答您的问题:当 ssh 客户端连接到服务器并请求交互式会话时，它可以选择为会话的服务器端请求 PTY(伪 tty).当它这样做时，它会通知服务器服务器应该用于 TTY 的行、列和终端类型.您的 SAN 可能会接受 PTY 请求并使用行和列值来格式化其输出.或者它可能不会.
Getting to your question: When an ssh client connects to a server and requests an interactive session, it can optionally request a PTY (pseudo-tty) for the server side of the session. When it does that, it informs the server of the lines, columns, and terminal type which the server should use for the TTY. Your SAN may honor PTY requests and use the lines and columns values to format its output. Or it may not.
ssh 客户端从 TTY 获取 PTY 请求的行和列作为其标准输入.这是 pexpect 用于与 ssh 通信的 PTY.这个问题讨论了如何为 pexpect 会话设置终端大小.据我所知，Ssh 不支持 LINES 或 COLUMNS 环境变量，所以我怀疑这是否可行.但是，在生成 ssh 后调用 child.setwinsize() 应该可以:
The ssh client gets the rows and columns for the PTY request from the TTY for its standard input. This is the PTY which pexpect is using to communicate with ssh.
this question discusses how to set the terminal size for a pexpect session. Ssh doesn't honor the LINES or COLUMNS environment variables as far as I can tell, so I doubt that would work. However, calling child.setwinsize() after spawning ssh ought to work:
child = pexpect.spawn(cmd)
child.setwinsize(400,400)
如果你有这个问题，你可以尝试在 ssh 之前通过本地调用 stty 来设置终端大小:
If you have trouble with this, you could try setting the terminal size by invoking stty locally before ssh:
child=pexpect.spawn('stty rows x cols y; ssh user@host')
最后，您需要确保 ssh 确实为会话请求了 PTY.它在某些情况下默认执行此操作，其中应包括您运行它的方式.但是它有一个命令行选项 -tt 来强制它分配一个 PTY.您可以将该选项添加到 ssh 命令行以确保:
Finally, you need to make sure that ssh actually requests a PTY for the session. It does this by default in some cases, which should include the way you are running it. But it has a command-line option -tt to force it to allocate a PTY. You could add that option to the ssh command line to make sure:
child=pexpect.spawn('ssh -tt user@host')
or
child=pexpect.spawn('stty rows x cols y; ssh -tt user@host')
这篇关于如何设置 pexpect ssh 会话的列宽?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
