Description of problem:
Plugins when run manually should not end with traceback. Instead they should collect what they can and end. In current build of sosreport haproxy and etcd plugins fail to run because of missing packages and files they are trying to collect.

Version-Release number of selected component (if applicable):
Unreleased!!! sos-3.5-1.el7.noarch

How reproducible:
100%

Steps to Reproduce:
1. sosreport --batch --all-logs -a  --debug -o etcd -e etcd
2. sosreport --batch --all-logs -a  --debug -o haproxy -e haproxy

Actual results:
# sosreport --batch --all-logs -a  --debug -o etcd -e etcd
. . .
 Setting up archive ...
 Setting up plugins ...
Traceback (most recent call last):
  File "/usr/sbin/sosreport", line 25, in <module>
    main(sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 1634, in main
    sos.execute()
KeyError: 'etcd'

> /usr/lib/python2.7/site-packages/sos/plugins/etcd.py(64)get_etcd_url()
-> ver = self.policy().package_manager.get_pkg_list()['etcd']
(Pdb)


# sosreport --batch --all-logs -a  --debug -o haproxy -e haproxy
. . .
 Setting up archive ...
 Setting up plugins ...
Traceback (most recent call last):
  File "/usr/sbin/sosreport", line 25, in <module>
    main(sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 1634, in main
    sos.execute()
IOError: [Errno 2] No such file or directory: '/etc/haproxy/haproxy.cfg'

> /usr/lib/python2.7/site-packages/sos/plugins/haproxy.py(48)setup()
-> for line in open("/etc/haproxy/haproxy.cfg").read().splitlines():
(Pdb)

Expected results:
Run and collect what you can and end gracefully with no tracebacks.

Additional info:
After installing haproxy and etcd haproxy plugin passes but etcd still fails but on different error...

# sosreport --batch --all-logs -a  --debug -o etcd -e etcd

sosreport (version 3.5)

This command will collect diagnostic and configuration information from
this Red Hat Enterprise Linux system and installed applications.

An archive containing the collected information will be generated in
/var/tmp/sos.JAKqXx and may be provided to a Red Hat support
representative.

Any information provided to Red Hat will be treated in accordance with
the published support policies at:

  https://access.redhat.com/support/

The generated archive may contain data considered sensitive and its
content should be reviewed by the originating organization before being
passed to any third party.

No changes will be made to system configuration.


 Setting up archive ...
 Setting up plugins ...
Traceback (most recent call last):
  File "/usr/sbin/sosreport", line 25, in <module>
    main(sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 1634, in main
    sos.execute()
NameError: global name 'subcmd' is not defined

> /usr/lib/python2.7/site-packages/sos/plugins/etcd.py(43)setup()
-> self.add_cmd_output(['%s %s' % (self.cmd, sub) for sub in subcmd])
(Pdb)