Is there a way to know the very instant that sshd becomes available on a remote box?

Question

Lots of cloud providers (AWS, GCE, etc) allow you to start up a machine instance, and then start billing you immediately. It can take anywhere from minutes to tens of minutes for the server to come up though. Is there a way to know (ideally from a script) the instant that sshd becomes available on the server?

Why? This is the perfect time to go refill your coffee. – Michael Hampton Oct 16 '13 at 02:51 — Michael Hampton, Oct 16 '13 at 02:51
I think I'm missing the reason for wanting to know this. – ewwhite Oct 16 '13 at 03:00 — ewwhite, Oct 16 '13 at 03:00

score 2 · Accepted Answer · answered Oct 16 '13 at 02:49

2

until nmap example.com -p 22 | grep -q open ; do sleep 1 ; done

answered Oct 16 '13 at 02:49

tylerl

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Is there a way to know the very instant that sshd becomes available on a remote box?

1 Answers1