Allow configuration of temp directory Nova uses

[Rafi Khardalian]

Nova uses the default system temp directory, which may not always be sized large enough to deal with operations such as snapshots. This is common on systems which have /tmp partitioned separately so that it can be mounted with noexec and nosuid for security reasons.

I've attached a patch to add a --tempdir flag to nova, which will allow for overriding the default to explicitly set the temp directory.

[Yaguang Tang (heut2008)]

openstack use gerrit for code commit.you can follow this guide http://wiki.openstack.org/HowToContribute#If_you.27re_a_developer.2C_start_here:

[Tom Fifield (fifieldt)]

The tempfile module here will respect any directory location set by TMPDIR, TEMP or TMP. Would it be better systems adminstration practice to encourage use of these variables, rather than adding a new configuration option at the application-level?

[Michael Still (mikal)]

I suspect a flag is easier for admins to use than to go off an alter the environment init starts tasks as.

[Michael Still (mikal)]

I don't think the attached patch goes far enough -- it doesn't address temporary files, just directories. This would be unexpected to someone who set that flag value.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/11999

[Michael Still (mikal)]

The proposed patch failed to receive enough common on gerrit, so I am throwing this bug back into the queue.

[Justin Shepherd (jshepher)]

Setting this as a application configuration option is a fairly common practice for applications.

example: http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_tmpdir

While this could be accomplished by adding ( TMPDIR|TEMP|TMP = /some/tmpdir ) to /etc/environment for Ubuntu and /etc/profile or /etc/profile.d/nova.sh for RHEL based systems.. I would hesitate to use that method as a systems administrator. I would be worried about what unintended consequences i would end up with by taking this route.. as the expected behavior for the rest of the system is to utilize /tmp for temp dirs/files..

Given that this function in nova can have huge space ramifications, the sane (from an ops perspective) approach is not to modify the global environment variables, but allow for fine grained administrator control by providing a configuration option.

[Justin Shepherd (jshepher)]

Michael.. if you want to re-submit, I will happily +1 this change as I have been burned a couple of times by this issue in production environments.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/20288

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/20288
Committed: http://github.com/openstack/nova/commit/e8386a27968f5a53f97681e7caf63b2243b7ed05
Submitter: Jenkins
Branch: master

commit e8386a27968f5a53f97681e7caf63b2243b7ed05
Author: Rafi Khardalian <email address hidden>
Date: Wed Jan 23 01:55:09 2013 +0000

    Allow users to specify a tmp location via config

    Fixes bug 981104

    Although the temporary directory used can be controlled via
    environment variables, this patch provides a way to define it
    explicitly via a config option.

    The default value is None, which behaves per the doc below:
    http://docs.python.org/2/library/tempfile.html#tempfile.tempdir

    Flags: DocImpact
    Change-Id: I47b6d8bac734f453c80d541b46086a30e847c859