Reducing injected interface template length to void hitting max length

[vaibhavhd]

Description of PR

Summary: Fix for add-topo failure seen when deploying testbeds with long injected interface names.
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Approach

What is the motivation for this PR?

Interface Name Size (IFNAMSIZ) is set to 16 characters https://elixir.bootlin.com/linux/v5.6/source/include/uapi/linux/if.h#L33

The interface name that add-topo script adds is indeed 16 chars (for eg. - inje-vmsvc1-1-58) , but 16 character limit set by Linux also includes a trailing NULL. So we should really limit the size to 15 USER VISIBLE length.

    "msg": "ret_code=255, error message=Error: argument \"inje-vmsvc1-1-58\" is wrong: \"dev\" not a valid ifname\n. cmd=ip link add inje-vmsvc1-1-58 type veth peer name d778a6eth58_t"
}

PLAY RECAP *********************************************************************
SVCSTR-SERV-1              : ok=114  changed=4    unreachable=0    failed=1    skipped=96   rescued=0    ignored=0

How did you do it?

Reduced the injected interface template size by 1 char.

Reproduced the error in the server.

server-1:~$ sudo ip link add inje-vmsvc1-1-58 type veth peer name d778a6eth58_t
Error: argument "inje-vmsvc1-1-58" is wrong: "dev" not a valid ifname
server-1:~$ 

Tried to reduce the size and the error is not seen anymore.

server-1:~$ sudo ip link add inje-vmsvc1-58 type veth peer name d778a6eth58_t
server-1:~$ 

How did you verify/test it?

Modified the template to one size small, and the add-topo script successfully passed.

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[vaibhavhd]

Retest vsimage please

[vaibhavhd]

Retest vsimage please

[vaibhavhd]

Retest vsimage please

[vaibhavhd]

Retest vsimage please

[vaibhavhd]

Retest vsimage please

[wangxin]

Retest vsimage please

[wangxin]

retest vsimage please

[wangxin]

retest vsimage please

[wangxin]

PRs #3359 and #3368 should have addressed this issue.