Can't Ansible be used to achieve your objective? Br,
-vu On Sat, Mar 4, 2017 at 6:28 PM, Cameron Simpson <c...@zip.com.au> wrote: > On 04Mar2017 13:34, bruce <badoug...@gmail.com> wrote: > >> tried the SSH without the "-t"... >> >> ssh -vvv crawl_user@67.205.151.11 "ls /crawl_tmp;" & >> >> this works -- no prob... returns as expected... >> >> this doesn't.. >> >> ssh -vvv -t crawl_user@67.205.151.11 "ls /crawl_tmp;" >> > > Well, it has no trailing "&"... > > -t causes the _remote_ end to allocate a terminal, which causes some > things to run differently (eg you can use use screen or tmux; most "ls" > commands will columnate output on a terminal, etc etc). However, for > background/batch commands you usually don't want this at all. Ssh turns > this on if attached to a terminal, and doesn't otherwise - that is what > gets you samless terminal access with a plain ssh to a remote host. > > Short answer: don't use -t. > > You also don't want to read from standard input - this is the -n option. > > The -f option is like -n, but completes the ssh connection/authentication > before backgrounding it. FOr maximum parallelism you don't want -f. > > Basicly you want a loop like this: > > set -x # trace the shell so you can see what's happening > for host in a b c d > do > ssh -n "$host" "some command here" & > done > wait > > You can compare that with the -f option flavour: > > set -x # trace the shell so you can see what's happening > for host in a b c d > do > ssh -f "$host" "some command here" > done > > The former is what you probably want; it is what I usually do. > > The latter does the authentication phase serially, then backgrounds the > ssh. It will be slower, but you could check which sshes failed > connection/authentication if that is a concern. Note that the background > ssh commands with -f are _not_ children of your shell, and you can't "wait" > for them as you can in the first instance. (You can block for them by > reading their (shared) stdout, but let us not go there.) > > The -t option is a red herring here; its use is more special purpose and > will only cause you trouble here. > > Cheers, > Cameron Simpson <c...@zip.com.au> > > _______________________________________________ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org >
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