Configuration Making it go my way

DevStack has always tried to be mostly-functional with a minimal amount of configuration. The number of options has ballooned as projects add features, new projects added and more combinations need to be tested. Historically DevStack obtained all local configuration and customizations from a localrc file. The number of configuration variables that are simply passed-through to the individual project configuration files is also increasing. The old mechanism for this (EXTRAS_OPTS and friends) required specific code for each file and did not scale well.

In Oct 2013 a new configuration method was introduced (in review 46768) to hopefully simplify this process and meet the following goals:

  • contain all non-default local configuration in a single file
  • be backward-compatible with localrc to smooth the transition process
  • allow settings in arbitrary configuration files to be changed

local.conf

The new configuration file is local.conf and resides in the root DevStack directory like the old localrc file. It is a modified INI format file that introduces a meta-section header to carry additional information regarding the configuration files to be changed.

The new header is similar to a normal INI section header but with double brackets ([[ ... ]]) and two internal fields separated by a pipe (|):

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

where <phase> is one of a set of phase names defined by stack.sh and <config-file-name> is the configuration filename. The filename is eval'ed in the stack.sh 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
  • pre-install - runs after the system packages are installed but before any of the source repositories are installed
  • install - runs immediately after the repo installations are complete
  • 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

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.

[[post-config|$NOVA_CONF]]
[DEFAULT]
use_syslog = True

[osapi_v3]
enabled = False

A specific meta-section local|localrc is used to provide a default localrc file (actually .localrc.auto). 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. More details on the contents of localrc are available.

[[local|localrc]]
FIXED_RANGE=10.254.1.0/24
ADMIN_PASSWORD=speciale
LOGFILE=$DEST/logs/stack.sh.log

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:

[[post-config|/$Q_PLUGIN_CONF_FILE]]

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

Minimal Configuration

While stack.sh 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 (FIXED_RANGE and FLOATING_RANGE, commented out below)
  • set the host IP if detection is unreliable (HOST_IP, commented out below)
[[local|localrc]]
ADMIN_PASSWORD=secrete
DATABASE_PASSWORD=$ADMIN_PASSWORD
RABBIT_PASSWORD=$ADMIN_PASSWORD
SERVICE_PASSWORD=$ADMIN_PASSWORD
SERVICE_TOKEN=a682f596-76f3-11e3-b3b2-e716f9080d50
#FIXED_RANGE=172.31.1.0/24
#FLOATING_RANGE=192.168.20.0/25
#HOST_IP=10.3.4.5

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

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 stack.sh but often is indeterminate on later runs due to the IP being moved from an Ethernet integace 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.

Common Configuration Variables

Set DevStack install directory
Default: DEST=/opt/stack
The DevStack install directory is set by the DEST variable. 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.
DEST=/opt/stack
stack.sh logging
Defaults: LOGFILE="" LOGDAYS=7 LOG_COLOR=True
By default stack.sh output is only written to the console where is 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 stack.sh.
LOGFILE=$DEST/logs/stack.sh.log
Old log files are cleaned automatically if LOGDAYS is set to the number of days of old log files to keep.
LOGDAYS=1
The some of the project logs (Nova, Cinder, etc) will be colorized by default (if SYSLOG is not set below); this can be turned off by setting LOG_COLOR False.
LOG_COLOR=False
Screen logging
Default: SCREEN_LOGDIR=""
By default DevStack runs the OpenStack services using screen which is useful for watching log and debug output. However, in automated testing the interactive screen sessions may not be available after the fact; setting SCREEN_LOGDIR enables logging of the screen sessions in the specified diretory. There will be one file per screen session named for the session name and a timestamp.
SCREEN_LOGDIR=$DEST/logs/screen
Note the use of DEST to locate the main install directory; this is why we suggest setting it in local.conf.

One syslog to bind them all
Default: SYSLOG=False SYSLOG_HOST=$HOST_IP SYSLOG_PORT=516
Logging all services to a single syslog can be convenient. Enable syslogging by setting SYSLOG to True. If the destination log host is not localhost SYSLOG_HOST and SYSLOG_PORT can be used to direct the message stream to the log host.
SYSLOG=True
SYSLOG_HOST=$HOST_IP
SYSLOG_PORT=516
A clean install every time
Default: RECLONE=""
By default stack.sh only clones the project repos if they do not exist in $DEST. stack.sh 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 $GIT_BASE.
RECLONE=yes
Swift
Default: SWIFT_HASH="" SWIFT_REPLICAS=1 SWIFT_DATA_DIR=$DEST/data/swift
Swift is now used as the back-end for the S3-like object store. When enabled Nova's objectstore (n-obj in ENABLED_SERVICES) is automatically disabled. Enable Swift by adding it services to ENABLED_SERVICES:
enable_service s-proxy s-object s-container s-account
Setting Swift's hash value is required and you will be prompted for it if Swift is enabled so just set it to something already:
SWIFT_HASH=66a3d6b56c1f479c8b4e70ab5c2000f5
For development purposes the default number of replicas is set to 1 to reduce the overhead required. To better simulate a production deployment set this to 3 or more.
SWIFT_REPLICAS=3
The data for Swift is stored in the source tree by default (in $DEST/swift/data) and can be moved by setting SWIFT_DATA_DIR. The specified directory will be created if it does not exist.
SWIFT_DATA_DIR=$DEST/data/swift
Note: Previously just enabling swift was sufficient to start the Swift services. That does not provide proper service granularity, particularly in multi-host configurations, and is considered deprecated. Some service combination tests now check for specific Swift services and the old blanket acceptance will longer work correctly.
Service Catalog Backend
Default: KEYSTONE_CATALOG_BACKEND=sql
DevStack uses Keystone's sql service catalog backend. An alternate template backend is also available. However, it does not support the service-* and endpoint-* commands of the keystone CLI. To do so requires the sql backend be enabled:
KEYSTONE_CATALOG_BACKEND=template
DevStack's default configuration in sql mode is set in files/keystone_data.sh
Cinder
Default: VOLUME_GROUP="stack-volumes" VOLUME_NAME_PREFIX="volume-" VOLUME_BACKING_FILE_SIZE=10250M
The logical volume group used to hold the Cinder-managed volumes is set by VOLUME_GROUP, 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.
VOLUME_GROUP="stack-volumes"
VOLUME_NAME_PREFIX="volume-"
VOLUME_BACKING_FILE_SIZE=10250M
Multi-host DevStack
Default: MULTI_HOST=False
Running DevStack with multiple hosts requires a custom local.conf section for each host. The master is the same as a single host installation with MULTI_HOST=True. The slaves have fewer services enabled and a couple of host variables pointing to the master.

Master
MULTI_HOST=True
Slave
MYSQL_HOST=w.x.y.z
RABBIT_HOST=w.x.y.z
GLANCE_HOSTPORT=w.x.y.z:9292
ENABLED_SERVICES=n-vol,n-cpu,n-net,n-api
API rate limits
Default: API_RATE_LIMIT=True
Integration tests such as Tempest will likely run afoul of the default rate limits configured for Nova. Turn off rate limiting during testing by setting API_RATE_LIMIT=False.
API_RATE_LIMIT=False

Examples

  • Eliminate a Cinder pass-through (CINDER_PERIODIC_INTERVAL):
    [[post-config|$CINDER_CONF]]
    [DEFAULT]
    periodic_interval = 60
    
  • Sample local.conf with screen logging enabled:
    [[local|localrc]]
    FIXED_RANGE=10.254.1.0/24
    NETWORK_GATEWAY=10.254.1.1
    LOGDAYS=1
    LOGFILE=$DEST/logs/stack.sh.log
    SCREEN_LOGDIR=$DEST/logs/screen
    ADMIN_PASSWORD=quiet
    DATABASE_PASSWORD=$ADMIN_PASSWORD
    RABBIT_PASSWORD=$ADMIN_PASSWORD
    SERVICE_PASSWORD=$ADMIN_PASSWORD
    SERVICE_TOKEN=a682f596-76f3-11e3-b3b2-e716f9080d50