alias patterns for BlueWaters and frontera conflict

[Roland Haas]

Both Blue Waters and Frontera define somewhat lenient regular expressions to match for their respective login nodes. Namely:

aliaspattern    = ^h2ologin[1-4](\.ncsa\.illinois\.edu)?$

and

aliaspattern    = login[1234](\.frontera\.tacc\.utexas\.edu)?$

In particular Frontera’s is too lenient since it misses the ^ anchor to anchor the regex to the beginning of the string making it match any node whose name contains login[1234]. This was encountered in real live by Cheng-Hsin Cheng  while testing the BBH gallery example on BlueWaters.

This confuses sim setup (and setup-silent) but does apparently not face sim whoami, which on Blue Waters at least returns bluewaters. Possibly b/c Blue Waters is alphabetically first.

There are two things that should be fixed by:

1. add a ^ to the alias pattern for Frontera
2. check whether one can leave in the FQDN instead of just the hostname itself since login since a fairly typical (if annoyingly generic) hostname (eg Stampede2, also TACC, uses the same name).
3. simfactory should warn / abort if more than one machine definition files aliaspattern matches I think (unless the pattern is emtpy, which we use for “alternative” machine definition files).

Should be backported.

[Roland Haas]

The missing ^ has been added to master in git hash 2207d60b "Frontera: add missing beginning of string anchor to alias pattern" of simfactory2 and ET_2021_05 in git hash 88a28cf6 "Frontera: add missing beginning of string anchor to alias pattern" of simfactory2 .

Cursory testing indicates that for Stampede2 one can use the FQDN for the alias pattern. I have no access to Frontera but expect the same to be true there as well (same computing center, same pattern of names). On BlueWaters on the other hand even hostname -f just returns h2ologin[1234] so the domain name of the alias pattern should be removed since it is never use (but the hostnames alone are already sufficiently unique).

[Gabriele Bozzola]

hostname -f returns login4.frontera.tacc.utexas.edu on Frontera. I can test any other change if you want so.

[Roland Haas]

If you could change aliaspattern to:

aliaspattern    = login[1234]\.frontera\.tacc\.utexas\.edu$

ie remove the (...)? optional marker, then check if ./simfactory/bin/sim whoami still reports frontera then we can update the machine definition file to avoid the confusion due to identical login node hostnames in different cluster domains.

[Gabriele Bozzola]

It works. You can also add the ^ in front.

[Roland Haas]

Applied as git hash db9c2090 "Frontera: use full hostname in aliaspattern" of simfactory2

‌

[Roland Haas]

Blue Waters was retired on Jan 3rd 2021.