12084 - STDIN detection in mco rpc fails when run non interactively

When running mco rpc from at, scripts, jenkins etc STDIN would not
be a tty but there would be no data on STDIN.

In the past it would assume there was discovery data on STDIN in
this scenario and fail.  Now it checks if the data read is empty
and does a normal discovery if it is

plugins/mcollective/application/rpc.rb

@@ -119,13 +119,15 @@ def main
     else
       # if there's stuff on STDIN assume its JSON that came from another
       # rpc or printrpc, we feed that in as discovery data
+      discover_args = {:verbose => true}
+
       unless STDIN.tty?
-        discovery_data = STDIN.read
-        mc.discover(:json => discovery_data)
-      else
-        mc.discover :verbose => true
+        discovery_data = STDIN.read.chomp
+        discover_args = {:json => discovery_data} unless discovery_data == ""
       end
 
+      mc.discover discover_args
+
       printrpc mc.send(configuration[:action], configuration[:arguments])
 
       printrpcstats :caption => "#{configuration[:agent]}##{configuration[:action]} call stats"

website/changelog.md

@@ -11,6 +11,7 @@ title: Changelog
 
 |Date|Description|Ticket|
 |----|-----------|------|
+|2012/01/27|Improve handling of discovery data on STDIN to avoid failures when run without a TTY and without supplying discovery data|12084|
 |2012/01/25|Allow the syslog facility to be configured|12109|
 |2012/01/13|Add a RPC agent validator to ensure input is one of list of known good values|11935|
 |2012/01/09|The printrpc helper did not correctly display empty strings in received output|11012|