Removing column header from output - shell

Question

I am running following command and output is shown below
and nova list
+--------------------------------------+---------------------------------------------------------------------+----------------+--------------------------------------------------+
| id | name | cidr | allocation_pools |
+--------------------------------------+---------------------------------------------------------------------+----------------+--------------------------------------------------+
| 1865fd7d-8971-4b2a-aaa3-c810189c2363 | test-inter-netwk | 192.168.1.0/24 | {"start": "192.168.1.2", "end": "192.168.1.254"} |
| 20214812-48f9-4938-bbd3-1b54cd796425 | App-Mgmt-subnet | 10.20.0.0/24 | {"start": "10.20.0.2", "end": "10.20.0.254"} |
| 7ab22397-e6a9-4a3d-96f0-9ebbce638f1e | vms2.1-net | 192.168.0.0/24 | {"start": "192.168.0.2", "end": "192.168.0.254"} |
| 8f97fc5e-53c6-4f29-9e4e-04f38a283452 | ddddd | 10.24.0.0/24 | {"start": "10.24.0.2", "end": "10.24.0.254"} |
| 990b338c-c980-456e-ade1-fc1a90f233e5 | Orch-Mgmt-subnet | 10.32.1.0/24 | {"start": "10.32.1.2", "end": "10.32.1.254"} |
| f386aca1-4c18-4b8e-9df7-a70111dea849 | TRANSIT-NEXTIP-Skyfall-eb07721aa407423e83e9641855f51e35-mseg-SUBNET | 10.22.0.0/24 | {"start": "10.22.0.2", "end": "10.22.0.254"} |
+--------------------------------------+---------------------------------------------------------------------+----------------+--------------------------------------------------+
Command
neutron subnet-list | awk -F "|" '{print $2}'
Output
output starts with two empty line and the text "id" and empty line.I need only id I am struggling to remove first few line.
id
1865fd7d-8971-4b2a-aaa3-c810189c2363
20214812-48f9-4938-bbd3-1b54cd796425
7ab22397-e6a9-4a3d-96f0-9ebbce638f1e
8f97fc5e-53c6-4f29-9e4e-04f38a283452
990b338c-c980-456e-ade1-fc1a90f233e5
f386aca1-4c18-4b8e-9df7-a70111dea849

Answer 1

You can add a conditional to your awk statement:
neutron subnet-list | awk -F "|" 'NR>2{print $2}'
That just says "IF the Record Number (NR) is greater than 2, then go ahead and print.
If you want to remove the blank after the id you could add that:
neutron subnet-list | awk -F "|" 'NR>2 && NR!=4{print $2}'
Which adds to the first conditional " And Record Number is not 4"
You could also just strip out any blank $2 fields to keep it simple:
neutron subnet-list | awk -F "|" '$2!=""{print $2}'

Answer 2

Use sed to print only lins that match (-n option and p at the end).
Look for a match at the beginning of the line, right after |.
Search for a string starting with at least 3 non-spaces (skipping ip but perhaps a problem with other neutron output) using [^ ]\{3\}.
Add the next characters until a space in the string to be remembered in \(..\).
Throw away the remaining characters with .*.
Put back the first (and only) remembered string with \1.
neutron subnet-list |sed -n 's/^| \([^ ]\{3\}[^ ]*\).*/\1/p'