Prompt pattern matches where it should NOT

[gbieli]

Describe the bug

Prompt pattern brn\-boll111\-.*?(\(.*?\))?[\>|\#] matches in show interfaces description on an interface that has brn-boll111-ap-02 Gi0 <LS:LIR> in its description.

General Information

OS:
RHEL7, python3.6

Netdev version:
asyncssh==1.18.0
netdev==0.9.3

Device OS:
Cisco IOS XE Software, Version 16.12.03s
C9300

Debug information

[2020-12-10 10:30:09,152 DEBUG base.py:388 - _read_until_prompt_or_pattern() pn:MainProcess pid:31799 t:MainThread ] Host <SNIP>: Reading pattern 'brn\-boll111\-.*?(\(.*?\))?[\>|\#]' or 'brn\-boll111\-.*?(\(.*?\))?[\>|\#]' was found: 'show interfaces description\r\nInterface Status Protocol Description\r\nVl1 up up not used <LS:C>\r\n<SNIP> <LS:CV>\r\nTe3/0/20 down down Access-Port with 802.1x - lan <LS:CV>\r\nTe3/0/21 down down Access-Port with 802.1x - lan <LS:CV>\r\nTe3/0/22 down down Access-Port with 802.1x - lan <LS:CV>\r\nTe3/0/23 up up Fabric Physical Link - brn-boll111-ap-02 Gi0 <LS:LIR>\r\nTe3/0/24 up up Fabric Physical Link - brn-boll111-ap-02 Gi0 <LS:LIR>\r\nGi3/1/1 admin down down not used <LS:C>\r\nGi3/1/2 admin down down not used <LS:C>\r\nGi3/1/3 admin down down not used <LS:C>\r\nGi3/1/4 admin down down not used <LS:C>\r\nTe3'

Additional context

Any ideas for a quick fix until the problem can be solved permanently?

[gbieli]

I think I found the issue. In the code only the first 12 characters from the base prompt are being used for the pattern. Our hostname has 18 characters. I fixed the issue as follows.

netdev/vendors/base.py - line 172:
_pattern = r"{prompt}.*?(\(.*?\))?[{delimiters}]"

changed to

_pattern = r"{prompt}(\(.*?\))?[{delimiters}]"

AND

netdev/vendors/base.py - line 252:
base_prompt = re.escape(self._base_prompt[:12])

changed to

base_prompt = re.escape(self._base_prompt)

Now it works without problems.