Revisiting 8b3800894c

(04:25:26 PM) rtyler: kohsuke: so `blimpy ssh` is going to return immediately now?
(04:25:41 PM) kohsuke: yes, it fails if ssh fails
(04:26:09 PM) ***rtyler is a bit confused
(04:26:14 PM) rtyler: this seems like a big UX change then
(04:26:21 PM) ***rtyler should read more carefully
(04:27:13 PM) kohsuke: Yes, modifying a test case made me wonder if there's a better way to do it
(04:28:00 PM) kohsuke: (though in practice you wouldn't see any change as "blimpy provision" does wait for ssh to come online)
(04:28:13 PM) rtyler: but a `blimpy ssh` won't log me into the machine?
(04:28:51 PM) kohsuke: I think just reporting ">> Connecting: SHIPNAME..." if the first attempt fails would be sufficient
(04:29:25 PM) kohsuke: The "gotcha" that made me write that patch is that my first attempt to use blimpy failed miserably at "blimpy ssh"
(04:29:51 PM) kohsuke: because it was trying a wrong user name, and I couldn't Ctrl+C it because of another bug that since then I fixed
(04:30:11 PM) rtyler: with aws and openstack it connects multiple times, usually the machine isn't accepting ssh connections right away
(04:30:14 PM) rtyler: especially on a fresh image
(04:30:25 PM) kohsuke: yes, I understand why you wrote it the way you did the first place
(04:31:17 PM) rtyler: heh
(04:31:21 PM) rtyler: alright
(04:32:05 PM) kohsuke: Let me change it to ">> Connecting: user@SHIPNAME:port" with dots added over time,
(04:32:15 PM) kohsuke: and if it's killed by SIGINT I'll run ssh one last time but without -q
(04:32:22 PM) kohsuke: so you see the error message
(04:32:41 PM) kohsuke: does that sound OK to you?
(04:34:30 PM) rtyler: that does sound good

It turns out some mode of failure includes ssh hanging (such as trying a
wrong port), so silently re-running SSH again wasn't very wise. Instead,
show the command line needed to let the user run the ssh command by
himself.

lib/blimpy/box.rb

@@ -197,11 +197,15 @@ module Blimpy
       end
     end
 
+    def ssh_commands(*args)
+      ['ssh', '-o', 'PasswordAuthentication=no',
+          '-o', 'StrictHostKeyChecking=no',
+          '-p', (ssh_port||22).to_s,
+          '-l', username, dns, *args]
+    end
+
     def ssh_into(*args)
-      run_command('ssh', '-o', 'PasswordAuthentication=no',
-                  '-o', 'StrictHostKeyChecking=no',
-                  '-p', ssh_port||22.to_s,
-                  '-l', username, dns, *args)
+      run_command(*ssh_commands(*args))
     end
 
     def scp_file(filename, directory='', *args)
@@ -240,10 +244,20 @@ module Blimpy
       until @ssh_connected
         # Run the `true` command and exit
         @ssh_connected = ssh_into('-q', 'true')
-        # if SSH is killed (such as Ctrl+C), abort right away
-        raise Exception, "ssh was killed: #{$?.exitstatus}" if $?.exitstatus>128 && $?.exitstatus<200
+        # if SSH is killed, don't repeat
+        if $?.signaled?
+          if $?.termsig==2
+            # if Ctrl+C, report what we were doing
+            puts "Failed to connect. To try it yourself:\n#{ssh_commands('-v','true').join(' ')}"
+          end
+          raise Exception, "ssh was killed: #{$?}"
+        end
 
         unless @ssh_connected
+          if !need_nl
+            p = ssh_port.nil? ? "" : ":#{ssh_port}"
+            print ">> Connecting #{username}@#{name}#{p}"
+          end
           if (Time.now.to_i - start) < 60
             print '.'
             need_nl = true

lib/blimpy/cli.rb

@@ -143,31 +143,8 @@ end
         end
       end
 
-      box.ssh_into *args
-    end
-
-    desc 'wait_for_ssh', 'Wait for SSHD to come online'
-    def wait_for_ssh(name=nil, *args)
-      unless name.nil?
-        box = box_by_name(name)
-        if box.nil?
-          puts "Could not find a blimp named \"#{name}\""
-          exit 1
-        end
-      else
-        blimps = current_blimps
-        unless blimps
-          puts "No Blimps running!"
-          exit 1
-        end
-
-        blimps.each do |blimp, data|
-          next unless data[:name]
-          box = box_by_name(data[:name])
-        end
-      end
-
       box.wait_for_sshd
+      box.ssh_into *args
     end
 
     desc 'scp BLIMP_NAME FILE_NAME', 'Securely copy FILE_NAME into the blimp'
@@ -178,6 +155,7 @@ end
         puts "Could not find a blimp named \"#{name}\""
         exit 1
       end
+      box.wait_for_sshd
       # Pass any extra commands along to the `scp` invocation
       box.scp_file(filename, '', *ARGV[3..-1])
     end