Allowing underscores in hostnames

[arlake228]

A user reported that a trace test result run from the command-line would not display because the result contained a hop without a valid hostname. The problem was that the hostname in question contained an underscore. I feel like the usual rule of thumb is hostnames are alpha-numeric plus dot and hyphen, but RFC-space is a bit more complicated than that. Wikipedia actually has a few paragraphs about this that do a pretty good job of explaining it: https://en.wikipedia.org/wiki/Hostname#Syntax. DNS definitely allows for underscores and it seems the browsers allow for underscores as well nowadays.

Also, just for details on the the command that led to this, the trace test in question actually completed and was stored in postgresql just fine. This was only a display issue on the CLI. Example:

pscheduler task trace  --dest 192.188.179.133
Submitting task...
Task URL:
https://kans-ps.es.net/pscheduler/tasks/aed8f68c-308a-46b2-8e8f-1cdef1259ac3
Running with tool 'traceroute'
Fetching first run...

Next scheduled run:
https://kans-ps.es.net/pscheduler/tasks/aed8f68c-308a-46b2-8e8f-1cdef1259ac3/runs/33968c71-b8e8-4e85-82e4-7571fcc6be7e
Starts 2025-02-07T16:22:27+00:00 (~3 seconds)
Ends   2025-02-07T16:22:35+00:00 (~7 seconds)
Waiting for result...

Problem fetching results: Failed to format result: At /paths/0/4/hostname: 'ornl1064-cr6--ornl_se143.ip.es.net' is not a 'ipv4'



No further runs scheduled.

If I lookup the result via the API, its all there. Also if I add --format json to the pscheduler command then I don't get an error since it skips the validation.