make glance-control a more fully featured process launcher

[Eoghan Glynn]

glance-control does not provide several features that are common among process launchers such as:

- the option not to throw the launched process's stdout/err on the floor, instead capture via syslog or some-such

- the option to monitor launched processes for unexpected death and respawn as necessary

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/3516
Committed: http://github.com/openstack/glance/commit/132c54f1739cbb201578a875b780f78c4d6b77a2
Submitter: Jenkins
Branch: master

commit 132c54f1739cbb201578a875b780f78c4d6b77a2
Author: Eoghan Glynn <email address hidden>
Date: Thu Jan 26 14:49:20 2012 +0000

    Add --capture-output option to glance-control.

    Fixes bug 923894

    Previously all stdout/err from glance services was discarded
    if launched via glance-control.

    The --capture-output option allows such output to be instead
    captured in the syslog.

    Non-termination output should be flushed to ensure timely
    arrival in /var/log/messages.

    Change-Id: I5c11ad4b9f7f321a3d1cab71e34c2a6707ef1b5e

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/3550
Committed: http://github.com/openstack/glance/commit/804396204e23ebb6c29c396396027bc3b09b0eab
Submitter: Jenkins
Branch: master

commit 804396204e23ebb6c29c396396027bc3b09b0eab
Author: Eoghan Glynn <email address hidden>
Date: Mon Jan 30 11:13:28 2012 +0000

    Respawn glance services on unexpected death.

    Fixes bug 923894

    Add new '--respawn' option to cause glance services launched via
    glance-control to be monitored for unexpected death and resuscitated
    as necessary.

    This option will cause glance-control itself to remain running.

    Deliberately stopped services are not respawned, neither are rapidly
    bouncing services (where process death occurred within one second
    of the last launch).

    Change-Id: I1a9a99cce9b6ad43274836e39ebe4f29c19455af