This means that fence-* package is not installed (most likely users wanting fence-agents or fence-virt). 

This might be confusing as it is not mentioned in the documentation so it should be mentioned there or it should be added as dependancy to pcs as most of the people would want fencing anyway.

Right now we don't require those packages since pcs can be run on a machine that doesn't have the cluster installed (it can control remote cluster nodes).  It does make sense to add an error message when they're running 'pcs stonith list' and nothing shows up (same for 'pcs resource list')

Created attachment 937931 [details]
proposed fix

Test:

1. Filter fence agents using non-matching filter
[root@rh70-node1 ~]# pcs stonith list badfilter
Error: No stonith agents matching the filter.
[root@rh70-node1 ~]# echo $?
1

2. Remove fence agents
[root@rh70-node1 ~]# yum remove fence-agents-*
[root@rh70-node1 ~]# yum remove fence-virt

3. List fence agents
[root@rh70-node1 ~]# pcs stonith list
Error: No stonith agents available. Do you have fence agents installed?
[root@rh70-node1 ~]# echo $?
1

4. Filter resources using non-matching filter
[root@rh70-node1 ~]# pcs resource list badfilter
Error: No resource agents matching the filter.
[root@rh70-node1 ~]# echo $?
1

Before Fix:
[root@rh70-node1 ~]# rpm -q pcs
pcs-0.9.115-32.el7.x86_64
[root@rh70-node1 ~]# pcs stonith list badfilter
[root@rh70-node1 ~]# echo $?
0
[root@rh70-node1 ~]# yum remove fence-agents-* fence-virt
{output omitted}
[root@rh70-node1 ~]# pcs stonith list
[root@rh70-node1 ~]# echo $?
0
[root@rh70-node1 ~]# pcs resource list badfilter
[root@rh70-node1 ~]# echo $?
0

After Fix:
[root@rh70-node1 ~]# rpm -q pcs
pcs-0.9.128-1.el7.x86_64
[root@rh70-node1 ~]# pcs stonith list badfilter
Error: No stonith agents matching the filter.
[root@rh70-node1 ~]# echo $?
1
[root@rh70-node1 ~]# yum remove fence-agents-* fence-virt
{output omitted}
[root@rh70-node1 ~]# pcs stonith list
Error: No stonith agents available. Do you have fence agents installed?
[root@rh70-node1 ~]# echo $?
1
[root@rh70-node1 ~]# pcs resource list badfilter
Error: No resource agents matching the filter.
[root@rh70-node1 ~]# echo $?
1

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-0415.html