devstack/doc/source/faq.rst

FAQ

General Questions

Can I use DevStack for production?

DevStack is targeted at developers and CI systems to use the raw upstream code. It makes many choices that are not appropriate for production systems.

Your best choice is probably to choose a distribution of OpenStack.

Why a shell script, why not chef/puppet/...

The script is meant to be read by humans (as well as ran by computers); it is the primary documentation after all. Using a recipe system requires everyone to agree and understand chef or puppet.

I'd like to help!

That isn't a question, but please do! The source for DevStack is at git.openstack.org and bug reports go to LaunchPad. Contributions follow the usual process as described in the developer guide. This Sphinx documentation is housed in the doc directory.

Why not use packages?

Unlike packages, DevStack leaves your cloud ready to develop -checkouts of the code and services running in screen. However, many people are doing the hard work of packaging and recipes for production deployments.

Why isn't $MY_FAVORITE_DISTRO supported?

DevStack is meant for developers and those who want to see how OpenStack really works. DevStack is known to run on the distro/release combinations listed in README.md. DevStack is only supported on releases other than those documented in README.md on a best-effort basis.

Are there any differences between Ubuntu and Centos/Fedora support?

Both should work well and are tested by DevStack CI.

Why can't I use another shell?

DevStack now uses some specific bash-ism that require Bash 4, such as associative arrays. Simple compatibility patches have been accepted in the past when they are not complex, at this point no additional compatibility patches will be considered except for shells matching the array functionality as it is very ingrained in the repo and project management.

Can I test on OS/X?

Some people have success with bash 4 installed via homebrew to keep running tests on OS/X.

Can I at least source openrc with zsh?

People have reported success with a special function to run openrc through bash for this

function sourceopenrc {
    pushd ~/devstack >/dev/null
    eval $(bash -c ". openrc $1 $2;env|sed -n '/OS_/ { s/^/export /;p}'")
    popd >/dev/null
}

Operation and Configuration

Can DevStack handle a multi-node installation?

Yes, see multinode lab guide <guides/multinode-lab>

How can I document the environment that DevStack is using?

DevStack includes a script (tools/info.sh) that gathers the versions of the relevant installed apt packages, pip packages and git repos. This is a good way to verify what Python modules are installed.

How do I turn off a service that is enabled by default?

Services can be turned off by adding disable_service xxx to local.conf (using n-vol in this example):

disable_service n-vol

Is enabling a service that defaults to off done with the reverse of the above?

Of course!

enable_service q-svc

How do I run a specific OpenStack release?

DevStack master tracks the upstream master of all the projects. If you would like to run a stable branch of OpenStack, you should use the corresponding stable branch of DevStack as well. For instance the stable/kilo version of DevStack will already default to all the projects running at stable/kilo levels.

Note: it's also possible to manually adjust the *_BRANCH variables further if you would like to test specific milestones, or even custom out of tree branches. This is done with entries like the following in your local.conf

[[local|localrc]]
GLANCE_BRANCH=11.0.0.0rc1
NOVA_BRANCH=12.0.0.0.rc1

Upstream DevStack is only tested with master and stable branches. Setting custom BRANCH definitions is not guarunteed to produce working results.

What can I do about RabbitMQ not wanting to start on my fresh new VM?

This is often caused by erlang not being happy with the hostname resolving to a reachable IP address. Make sure your hostname resolves to a working IP address; setting it to 127.0.0.1 in /etc/hosts is often good enough for a single-node installation. And in an extreme case, use clean.sh to eradicate it and try again.

Configure local.conf thusly:

[[local|localrc]]
HEAT_STANDALONE=True
ENABLED_SERVICES=rabbit,mysql,heat,h-api,h-api-cfn,h-api-cw,h-eng
KEYSTONE_SERVICE_HOST=<keystone-host>
KEYSTONE_AUTH_HOST=<keystone-host>

Why are my configuration changes ignored?

You may have run into the package prerequisite installation timeout. tools/install_prereqs.sh has a timer that skips the package installation checks if it was run within the last PREREQ_RERUN_HOURS hours (default is 2). To override this, set FORCE_PREREQ=1 and the package checks will never be skipped.

Miscellaneous

tools/fixup_stuff.sh is broken and shouldn't 'fix' just one version of packages.

Stuff in there is to correct problems in an environment that need to be fixed elsewhere or may/will be fixed in a future release. In the case of httplib2 and prettytable specific problems with specific versions are being worked around. If later releases have those problems than we'll add them to the script. Knowing about the broken future releases is valuable rather than polling to see if it has been fixed.