#545: Use ssh ProxyCommand instead of multiple ssh commands --------------------------+------------------------------------------------- Reporter: eschnett | Owner: eschnett Type: enhancement | Status: review Priority: major | Milestone: Component: SimFactory | Version: Resolution: | Keywords: --------------------------+-------------------------------------------------
Comment (by knarf):
ssh proxies can be nested, however it turns out that the %h syntax is a problem here: every %h is replaced by ssh, regardless of quoting. Thus, simfactory would have to do that itself - which isn't a problem since that is known. Similarly for the port, but there simfactory would have to parse non-standard ports from given options.
One example for -> numrel07 -> numrel08 -> queenbee would be:
ssh -o ProxyCommand='ssh -o ProxyCommand='''ssh numrel07.cct.lsu.edu nc numrel08.cct.lsu.edu %p''' numrel08.cct.lsu.edu nc qb.loni.org %p' qb.loni.org
I agree with what you say about quoting. An empty string however, should not be quoted. It should always remain an empty string (although both options should work). It's not necessary and clutters the output, especially if these quotes are quoted again. An empty string, when passed to a shell, remains an empty string, regardless if quoted or not. Ideally, QuoteSafe would be able to tell if the argument needs quoting at all, and would only quote in that case - but of course that is optional.