DevStack configuration is modified via the file local.conf. It is a modified INI format file that introduces a meta-section header to carry additional information regarding the configuration files to be changed.

A sample is provided in devstack/samples

The new header is similar to a normal INI section header but with double brackets ([[ ... ]]) and two internal fields separated by a pipe (|). Note that there are no spaces between the double brackets and the internal fields. Likewise, there are no spaces between the pipe and the internal fields:

'[[' <phase> '|' <config-file-name> ']]'

where <phase> is one of a set of phase names defined by and <config-file-name> is the configuration filename. The filename is eval’ed in the context so all environment variables are available and may be used. Using the project config file variables in the header is strongly suggested (see the NOVA_CONF example below). If the path of the config file does not exist it is skipped.

The defined phases are:

  • local - extracts localrc from local.conf before stackrc is sourced
  • post-config - runs after the layer 2 services are configured and before they are started
  • extra - runs after services are started and before any files in extra.d are executed
  • post-extra - runs after files in extra.d are executed

The file is processed strictly in sequence; meta-sections may be specified more than once but if any settings are duplicated the last to appear in the file will be used.

use_syslog = True

enabled = False

A specific meta-section local|localrc is used to provide a default localrc file (actually This allows all custom settings for DevStack to be contained in a single file. If localrc exists it will be used instead to preserve backward-compatibility.


Note that Q_PLUGIN_CONF_FILE is unique in that it is assumed to NOT start with a / (slash) character. A slash will need to be added:


Also note that the localrc section is sourced as a shell script fragment and MUST conform to the shell requirements, specifically no whitespace around = (equals).


openrc configures login credentials suitable for use with the OpenStack command-line tools. openrc sources stackrc at the beginning (which in turn sources the localrc section of local.conf) in order to pick up HOST_IP and/or SERVICE_HOST to use in the endpoints. The values shown below are the default values.


Keystone has standardized the term project as the entity that owns resources. In some places references still exist to the previous term tenant for this use. Also, project_name is preferred to project_id. OS_TENANT_NAME remains supported for compatibility with older tools.


In addition to the owning entity (project), OpenStack calls the entity performing the action user.


Keystone’s default authentication requires a password be provided. The usual cautions about putting passwords in environment variables apply, for most DevStack uses this may be an acceptable tradeoff.


Set API endpoint host using HOST_IP. SERVICE_HOST may also be used to specify the endpoint, which is convenient for some local.conf configurations. Typically, HOST_IP is set in the localrc section.


Authenticating against an OpenStack cloud using Keystone returns a Token and Service Catalog. The catalog contains the endpoints for all services the user/tenant has access to - including Nova, Glance, Keystone and Swift.


Set command-line client log level to DEBUG. These are commented out by default.


Minimal Configuration

While is happy to run without a localrc section in local.conf, devlife is better when there are a few minimal variables set. This is an example of a minimal configuration that touches the values that most often need to be set.

  • no logging
  • pre-set the passwords to prevent interactive prompts
  • move network ranges away from the local network (IPV4_ADDRS_SAFE_TO_USE and FLOATING_RANGE, commented out below)
  • set the host IP if detection is unreliable (HOST_IP, commented out below)

If the *_PASSWORD variables are not set here you will be prompted to enter values for them by

The network ranges must not overlap with any networks in use on the host. Overlap is not uncommon as RFC-1918 ‘private’ ranges are commonly used for both the local networking and Nova’s fixed and floating ranges.

HOST_IP is normally detected on the first run of but often is indeterminate on later runs due to the IP being moved from an Ethernet interface to a bridge on the host. Setting it here also makes it available for openrc to set OS_AUTH_URL. HOST_IP is not set by default.

HOST_IPV6 is normally detected on the first run of but will not be set if there is no IPv6 address on the default Ethernet interface. Setting it here also makes it available for openrc to set OS_AUTH_URL. HOST_IPV6 is not set by default.

Historical Notes

Historically DevStack obtained all local configuration and customizations from a localrc file. In Oct 2013 the local.conf configuration method was introduced (in review 46768) to simplify this process.

Configuration Notes

Service Repos

The Git repositories used to check out the source for each service are controlled by a pair of variables set for each service. *_REPO points to the repository and *_BRANCH selects which branch to check out. These may be overridden in local.conf to pull source from a different repo for testing, such as a Gerrit branch proposal. GIT_BASE points to the primary repository server.


To pull a branch directly from Gerrit, get the repo and branch from the Gerrit review page:

git fetch refs/changes/50/5050/1 && git checkout FETCH_HEAD

The repo is the stanza following fetch and the branch is the stanza following that:


Installation Directory

The DevStack install directory is set by the DEST variable. By default it is /opt/stack.

By setting it early in the localrc section you can reference it in later variables. It can be useful to set it even though it is not changed from the default value.



Enable Logging

By default output is only written to the console where it runs. It can be sent to a file in addition to the console by setting LOGFILE to the fully-qualified name of the destination log file. A timestamp will be appended to the given filename for each run of


Old log files are cleaned automatically if LOGDAYS is set to the number of days of old log files to keep.


Some coloring is used during the DevStack runs to make it easier to see what is going on. This can be disabled with:


Logging the Service Output

By default, services run under systemd and are natively logging to the systemd journal.

To query the logs use the journalctl command, such as:

journalctl --unit devstack@*

More examples can be found in Querying Logs.

Example Logging Configuration

For example, non-interactive installs probably wish to save output to a file, keep service logs and disable color in the stored files.


Database Backend

Multiple database backends are available. The available databases are defined in the lib/databases directory. mysql is the default database, choose a different one by putting the following in the localrc section:

disable_service mysql
enable_service postgresql

mysql is the default database.

RPC Backend

Support for a RabbitMQ RPC backend is included. Additional RPC backends may be available via external plugins. Enabling or disabling RabbitMQ is handled via the usual service functions and ENABLED_SERVICES.

Example disabling RabbitMQ in local.conf:

disable_service rabbit

Apache Frontend

The Apache web server can be enabled for wsgi services that support being deployed under HTTPD + mod_wsgi. By default, services that recommend running under HTTPD + mod_wsgi are deployed under Apache. To use an alternative deployment strategy (e.g. eventlet) for services that support an alternative to HTTPD + mod_wsgi set ENABLE_HTTPD_MOD_WSGI_SERVICES to False in your local.conf.

Each service that can be run under HTTPD + mod_wsgi also has an override toggle available that can be set in your local.conf.

Keystone is run under Apache with mod_wsgi by default.

Example (Keystone)


Example (Nova):


Example (Swift):


Example (Heat):


Example (Cinder):


Libraries from Git

By default devstack installs OpenStack server components from git, however it installs client libraries from released versions on pypi. This is appropriate if you are working on server development, but if you want to see how an unreleased version of the client affects the system you can have devstack install it from upstream, or from local git trees by specifying it in LIBS_FROM_GIT. Multiple libraries can be specified as a comma separated list.


Setting the variable to ALL will activate the download for all libraries.

Virtual Environments

Enable the use of Python virtual environments by setting USE_VENV to True. This will enable the creation of venvs for each project that is defined in the PROJECT_VENV array.

Each entry in the PROJECT_VENV array contains the directory name of a venv to be used for the project. The array index is the project name. Multiple projects can use the same venv if desired.


ADDITIONAL_VENV_PACKAGES is a comma-separated list of additional packages to be installed into each venv. Often projects will not have certain packages listed in its requirements.txt file because they are ‘optional’ requirements, i.e. only needed for certain configurations. By default, the enabled databases will have their Python bindings added when they are enabled.

ADDITIONAL_VENV_PACKAGES="python-foo, python-bar"

A clean install every time

By default only clones the project repos if they do not exist in $DEST. will freshen each repo on each run if RECLONE is set to yes. This avoids having to manually remove repos in order to get the current branch from $GIT_BASE.


Upgrade packages installed by pip

By default only installs Python packages if no version is currently installed or the current version does not match a specified requirement. If PIP_UPGRADE is set to True then existing required Python packages will be upgraded to the most recent version that matches requirements.


Guest Images

Images provided in URLS via the comma-separated IMAGE_URLS variable will be downloaded and uploaded to glance by DevStack.

Default guest-images are predefined for each type of hypervisor and their testing-requirements in Setting DOWNLOAD_DEFAULT_IMAGES=False will prevent DevStack downloading these default images; in that case, you will want to populate IMAGE_URLS with sufficient images to satisfy testing-requirements.


Instance Type

DEFAULT_INSTANCE_TYPE can be used to configure the default instance type. When this parameter is not specified, Devstack creates additional micro & nano flavors for really small instances to run Tempest tests.

For guests with larger memory requirements, DEFAULT_INSTANCE_TYPE should be specified in the configuration file so Tempest selects the default flavors instead.

KVM on Power with QEMU 2.4 requires 512 MB to load the firmware - QEMU 2.4 - PowerPC so users running instances on ppc64/ppc64le can choose one of the default created flavors as follows:


IP Version

IP_VERSION can be used to configure Neutron to create either an IPv4, IPv6, or dual-stack self-service project data-network by with either IP_VERSION=4, IP_VERSION=6, or IP_VERSION=4+6 respectively.


The following optional variables can be used to alter the default IPv6 behavior:


Note: IPV6_ADDRS_SAFE_TO_USE and IPV6_PRIVATE_NETWORK_GATEWAY can be configured with any valid IPv6 prefix. The default values make use of an auto-generated IPV6_GLOBAL_ID to comply with RFC4193.

Service Version

DevStack can enable service operation over either IPv4 or IPv6 by setting SERVICE_IP_VERSION to either SERVICE_IP_VERSION=4 or SERVICE_IP_VERSION=6 respectively.

When set to 4 devstack services will open listen sockets on and service endpoints will be registered using HOST_IP as the address.

When set to 6 devstack services will open listen sockets on :: and service endpoints will be registered using HOST_IPV6 as the address.

The default value for this setting is 4. Dual-mode support, for example 4+6 is not currently supported. HOST_IPV6 can optionally be used to alter the default IPv6 address




See the neutron configuration guide for details on configuration of Neutron


Swift is disabled by default. When enabled, it is configured with only one replica to avoid being IO/memory intensive on a small VM.

If you would like to enable Swift you can add this to your localrc section:

enable_service s-proxy s-object s-container s-account

If you want a minimal Swift install with only Swift and Keystone you can have this instead in your localrc section:

enable_service key mysql s-proxy s-object s-container s-account

If you only want to do some testing of a real normal swift cluster with multiple replicas you can do so by customizing the variable SWIFT_REPLICAS in your localrc section (usually to 3).

You can manually override the ring building to use specific storage nodes, for example when you want to test a multinode environment. In this case you have to set a space-separated list of IPs in SWIFT_STORAGE_IPS in your localrc section that should be used as Swift storage nodes. Please note that this does not create a multinode setup, it is only used when adding nodes to the Swift rings.

Swift S3

If you are enabling swift3 in ENABLED_SERVICES DevStack will install the swift3 middleware emulation. Swift will be configured to act as a S3 endpoint for Keystone so effectively replacing the nova-objectstore.

Only Swift proxy server is launched in the systemd system all other services are started in background and managed by swift-init tool.


If tempest has been successfully configured, a basic set of smoke tests can be run as follows:

$ cd /opt/stack/tempest
$ tox -efull  tempest.scenario.test_network_basic_ops

By default tempest is downloaded and the config file is generated, but the tempest package is not installed in the system’s global site-packages (the package install includes installing dependences). So tempest won’t run outside of tox. If you would like to install it add the following to your localrc section:



If you would like to use Xenserver as the hypervisor, please refer to the instructions in ./tools/xen/


Cells is an alternative scaling option. To setup a cells environment add the following to your localrc section:

enable_service n-cell

Be aware that there are some features currently missing in cells, one notable one being security groups. The exercises have been patched to disable functionality not supported by cells.


The logical volume group used to hold the Cinder-managed volumes is set by VOLUME_GROUP_NAME, the logical volume name prefix is set with VOLUME_NAME_PREFIX and the size of the volume backing file is set with VOLUME_BACKING_FILE_SIZE.



Multi-Region Setup

We want to setup two devstack (RegionOne and RegionTwo) with shared keystone (same users and services) and horizon. Keystone and Horizon will be located in RegionOne. Full spec is available at:

In RegionOne:


In RegionTwo:

disable_service horizon

In the devstack for RegionOne, we set REGION_NAME as RegionOne, so region of the services started in this devstack are registered as RegionOne. In devstack for RegionTwo, similarly, we set REGION_NAME as RegionTwo since we want services started in this devstack to be registered in RegionTwo. But Keystone service is started and registered in RegionOne, not RegionTwo, so we use KEYSTONE_REGION_NAME to specify the region of Keystone service. KEYSTONE_REGION_NAME has a default value the same as REGION_NAME thus we omit it in the configuration of RegionOne.

Disabling Identity API v2

The Identity API v2 is deprecated as of Mitaka and it is recommended to only use the v3 API. It is possible to setup keystone without v2 API, by doing:



exerciserc is used to configure settings for the exercise scripts. The values shown below are the default values. These can all be overridden by setting them in the localrc section.

  • Max time to wait while vm goes from build to active state

  • Max time to wait for proper IP association and dis-association.

  • Max time till the vm is bootable

  • Max time from run instance command until it is running

  • Max time to wait for a vm to terminate