Install plugin failure does not stop script execution

[CloCkWeRX]

If you install_plugin something invalid, and it fails, the ruby block does not check the exit code and fail properly.

This leads to silent failures if your plugin does not install.

[karmi]

Thanks, valid concern. I've merged your commit, but the problem is that the plugin script does not return correct exit status on failure:

vagrant@precise64:~$ /usr/local/bin/plugin --install FOOBAR
-> Installing FOOBAR...

Failed to install FOOBAR, reason: plugin directory /usr/local/elasticsearch-0.90.3/plugins is read only
vagrant@precise64:~$ echo $?
0

# -----

vagrant@precise64:~$ sudo /usr/local/bin/plugin --install FOOBAR
-> Installing FOOBAR...
Failed to install FOOBAR, reason: failed to download out of all possible locations..., use -verbose to get detailed information
vagrant@precise64:~$ echo $?
0

Related: elastic/elasticsearch#3556

[karmi]

Update, solved in elastic/elasticsearch#3463 already, will be part of the next release.