Use TextFSM to find allowed VLANs on trunk

Question

I'm trying to set up a TextFSM template for NTC ansible which will only pull the Vlans allowed on the trunk from the output of a "show interface trunk" command and can't seem to get what I want. It is giving me all the lines instead of just the single line that I want. The output of the command looks like this:

switch#sh int g9/17 trunk

Port                Mode         Encapsulation  Status        Native vlan
Gi9/17              on           802.1q         trunking      1

Port                Vlans allowed on trunk
Gi9/17              501,503,513,540,950-957

Port                Vlans allowed and active in management domain
Gi9/17              501,503,513,540,950-957

Port                Vlans in spanning tree forwarding state and not pruned
Gi9/17              501,503,513,540,950-957

In this output, I only want to return the line below "Vlans allowed on trunk" and not the other repeat lines that have the same info. My template looks like this:

Value PORT (\S+)
Value VLANS (.*)

Start
  ^Port.*Vlans allowed on trunk -> Begin

Begin
  ^(?=\s{0,9}${PORT})\s+${VLANS} -> Record
  ^Port.*Vlans allowed and active in management domain -> End

Answer 1

Make regular expressions more specific and get the desired result (maybe :).

import io
import textfsm

template = io.StringIO("""\
Value Port (\S+(/\d+)?)
Value Vlans (\d+([-,]\d+)+)

Start
  ^Port\s+Vlans allowed on trunk$$ -> Begin

Begin
  ^${Port}\s+${Vlans}$$ -> Record
  ^Port\s+Vlans allowed and active in management domain$$ -> End
""")
fsm = textfsm.TextFSM(template)
result = fsm.ParseText("""\
switch#sh int g9/17 trunk

Port                Mode         Encapsulation  Status        Native vlan
Gi9/17              on           802.1q         trunking      1

Port                Vlans allowed on trunk
Gi9/17              501,503,513,540,950-957

Port                Vlans allowed and active in management domain
Gi9/17              501,503,513,540,950-957

Port                Vlans in spanning tree forwarding state and not pruned
Gi9/17              501,503,513,540,950-957
""")
print(result)

[['Gi9/17', '501,503,513,540,950-957']]