Add PostgreSQL support to devstack

This patch adds an interface for supporting multiple database backend types and implemnts support for PostgreSQL. It also adds a function, use_exclusive_service, which serves as a base for enabling a service that conflicts with other services. The use_database function uses it, and it might also be useful for selecting messaging backends. MySQL is still selected by default. Tested on Fedora 17 and Ubuntu 12.04 with MySQL and PostgreSQL. Implements blueprint postgresql-support Change-Id: I4b1373e25676fd9a9809fe70cb4a6450a2479174
2012-11-01 16:12:39 -04:00 · 2012-11-01 16:12:39 -04:00 · 428af5a257
commit 428af5a257
parent 98b26ab358
14 changed files with 356 additions and 113 deletions
--- a/README.md
+++ b/README.md
@ -57,6 +57,15 @@ If the EC2 API is your cup-o-tea, you can create credentials and use euca2ools:

 You can override environment variables used in `stack.sh` by creating file name `localrc`.  It is likely that you will need to do this to tweak your networking configuration should you need to access your cloud from a different host.

+# Database Backend
+
+Multiple database backends are available. The available databases are defined in the lib/databases directory.
+To choose a database backend, add a line to your `localrc` like:
+
+    use_database postgresql
+
+By default, the mysql database backend is used.
+
 # RPC Backend

 Multiple RPC backends are available. Currently, this
--- a/files/apts/postgresql
+++ b/files/apts/postgresql
@ -0,0 +1 @@
+python-psycopg2
--- a/files/rpms/postgresql
+++ b/files/rpms/postgresql
@ -0,0 +1 @@
+python-psycopg2
--- a/15
+++ b/15
@ -836,6 +836,21 @@ function upload_image() {
    fi
 }

+# Toggle enable/disable_service for services that must run exclusive of each other
+#  $1 The name of a variable containing a space-separated list of services
+#  $2 The name of a variable in which to store the enabled service's name
+#  $3 The name of the service to enable
+function use_exclusive_service {
+    local options=${!1}
+    local selection=$3
+    out=$2
+    [ -z $selection ] || [[ ! "$options" =~ "$selection" ]] && return 1
+    for opt in $options;do
+        [[ "$opt" = "$selection" ]] && enable_service $opt || disable_service $opt
+    done
+    eval "$out=$selection"
+    return 0
+}

 # Wrapper for ``yum`` to set proxy environment variables
 # Uses globals ``OFFLINE``, ``*_proxy`
--- a/lib/cinder
+++ b/lib/cinder
@ -112,7 +112,9 @@ function configure_cinder() {
    iniset $CINDER_CONF DEFAULT volume_group $VOLUME_GROUP
    iniset $CINDER_CONF DEFAULT volume_name_template ${VOLUME_NAME_PREFIX}%s
    iniset $CINDER_CONF DEFAULT iscsi_helper tgtadm
-    iniset $CINDER_CONF DEFAULT sql_connection $BASE_SQL_CONN/cinder?charset=utf8
+    local dburl
+    database_connection_url dburl cinder
+    iniset $CINDER_CONF DEFAULT sql_connection $dburl
    iniset $CINDER_CONF DEFAULT api_paste_config $CINDER_API_PASTE_INI
    iniset $CINDER_CONF DEFAULT root_helper "sudo ${CINDER_ROOTWRAP}"
    iniset $CINDER_CONF DEFAULT osapi_volume_extension cinder.api.openstack.volume.contrib.standard_extensions
@ -141,10 +143,9 @@ function init_cinder() {
    # Force nova volumes off
    NOVA_ENABLED_APIS=$(echo $NOVA_ENABLED_APIS | sed "s/osapi_volume,//")

-    if is_service_enabled mysql; then
+    if is_service_enabled $DATABASE_BACKENDS; then
        # (re)create cinder database
-        mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS cinder;'
-        mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE cinder;'
+        recreate_database cinder utf8

        # (re)create cinder database
        $CINDER_BIN_DIR/cinder-manage db sync
--- a/lib/database
+++ b/lib/database
@ -0,0 +1,103 @@
+# lib/database
+# Interface for interacting with different database backends
+
+# Dependencies:
+# DATABASE_BACKENDS variable must contain a list of available database backends
+# DATABASE_TYPE variable must be set
+
+# Each database must implement four functions:
+#   recreate_database_$DATABASE_TYPE
+#   install_database_$DATABASE_TYPE
+#   configure_database_$DATABASE_TYPE
+#   database_connection_url_$DATABASE_TYPE
+#
+# and call register_database $DATABASE_TYPE
+
+# Save trace setting
+XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+# Register a database backend
+#  $1 The name of the database backend
+function register_database {
+    [ -z "$DATABASE_BACKENDS" ] && DATABASE_BACKENDS=$1 || DATABASE_BACKENDS+=" $1"
+}
+
+for f in $TOP_DIR/lib/databases/*; do source $f; done
+
+# Set the database type based on the configuration
+function initialize_database_backends {
+    for backend in $DATABASE_BACKENDS; do
+        is_service_enabled $backend && DATABASE_TYPE=$backend
+    done
+
+    [ -z "$DATABASE_TYPE" ] && return 1
+
+    # For backward-compatibility, read in the MYSQL_HOST/USER variables and use
+    # them as the default values for the DATABASE_HOST/USER variables.
+    MYSQL_HOST=${MYSQL_HOST:-localhost}
+    MYSQL_USER=${MYSQL_USER:-root}
+
+    DATABASE_HOST=${DATABASE_HOST:-${MYSQL_HOST}}
+    DATABASE_USER=${DATABASE_USER:-${MYSQL_USER}}
+
+    if [ -n "$MYSQL_PASSWORD" ]; then
+        DATABASE_PASSWORD=$MYSQL_PASSWORD
+    else
+        read_password DATABASE_PASSWORD "ENTER A PASSWORD TO USE FOR THE DATABASE."
+    fi
+
+    # We configure Nova, Horizon, Glance and Keystone to use MySQL as their
+    # database server.  While they share a single server, each has their own
+    # database and tables.
+
+    # By default this script will install and configure MySQL.  If you want to
+    # use an existing server, you can pass in the user/password/host parameters.
+    # You will need to send the same ``DATABASE_PASSWORD`` to every host if you are doing
+    # a multi-node DevStack installation.
+
+    # NOTE: Don't specify ``/db`` in this string so we can use it for multiple services
+    BASE_SQL_CONN=${BASE_SQL_CONN:-${DATABASE_TYPE}://$DATABASE_USER:$DATABASE_PASSWORD@$DATABASE_HOST}
+
+    return 0
+}
+
+# Set the database backend to use
+#  $1 The name of the database backend to use (mysql, postgresql, ...)
+function use_database {
+    use_exclusive_service DATABASE_BACKENDS DATABASE_TYPE $1 && return 0
+    ret=$?
+    echo "Invalid database '$1'"
+    return $ret
+}
+
+# Recreate a given database
+#  $1 The name of the database
+#  $2 The character set/encoding of the database
+function recreate_database {
+    local db=$1
+    local charset=$2
+    recreate_database_$DATABASE_TYPE $db $charset
+}
+
+# Install the database
+function install_database {
+    install_database_$DATABASE_TYPE
+}
+
+# Configure and start the database
+function configure_database {
+    configure_database_$DATABASE_TYPE
+}
+
+# Generate an SQLAlchemy connection URL and store it in a variable
+#  $1 The variable name in which to store the connection URL
+#  $2 The name of the database
+function database_connection_url {
+    local var=$1
+    local db=$2
+    database_connection_url_$DATABASE_TYPE $var $db
+}
+
+# Restore xtrace
+$XTRACE
--- a/lib/databases/mysql
+++ b/lib/databases/mysql
@ -0,0 +1,93 @@
+# lib/mysql
+# Functions to control the configuration and operation of the MySQL database backend
+
+# Dependencies:
+# DATABASE_{HOST,USER,PASSWORD} must be defined
+
+# Save trace setting
+XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+register_database mysql
+
+function recreate_database_mysql {
+    local db=$1
+    local charset=$2
+    mysql -u$DATABASE_USER -p$DATABASE_PASSWORD -e "DROP DATABASE IF EXISTS $db;"
+    mysql -u$DATABASE_USER -p$DATABASE_PASSWORD -e "CREATE DATABASE $db CHARACTER SET $charset;"
+}
+
+function configure_database_mysql {
+    echo_summary "Configuring and starting MySQL"
+
+    if [[ "$os_PACKAGE" = "deb" ]]; then
+        MY_CONF=/etc/mysql/my.cnf
+        MYSQL=mysql
+    else
+        MY_CONF=/etc/my.cnf
+        MYSQL=mysqld
+    fi
+
+    # Start mysql-server
+    if [[ "$os_PACKAGE" = "rpm" ]]; then
+        # RPM doesn't start the service
+        start_service $MYSQL
+        # Set the root password - only works the first time
+        sudo mysqladmin -u root password $DATABASE_PASSWORD || true
+    fi
+    # Update the DB to give user ‘$DATABASE_USER’@’%’ full control of the all databases:
+    sudo mysql -uroot -p$DATABASE_PASSWORD -h127.0.0.1 -e "GRANT ALL PRIVILEGES ON *.* TO '$DATABASE_USER'@'%' identified by '$DATABASE_PASSWORD';"
+
+    # Now update ``my.cnf`` for some local needs and restart the mysql service
+
+    # Change ‘bind-address’ from localhost (127.0.0.1) to any (0.0.0.0)
+    sudo sed -i '/^bind-address/s/127.0.0.1/0.0.0.0/g' $MY_CONF
+
+    # Set default db type to InnoDB
+    if sudo grep -q "default-storage-engine" $MY_CONF; then
+        # Change it
+        sudo bash -c "source $TOP_DIR/functions; iniset $MY_CONF mysqld default-storage-engine InnoDB"
+    else
+        # Add it
+        sudo sed -i -e "/^\[mysqld\]/ a \
+default-storage-engine = InnoDB" $MY_CONF
+    fi
+
+    restart_service $MYSQL
+}
+
+function install_database_mysql {
+    if [[ "$os_PACKAGE" = "deb" ]]; then
+        # Seed configuration with mysql password so that apt-get install doesn't
+        # prompt us for a password upon install.
+        cat <<MYSQL_PRESEED | sudo debconf-set-selections
+mysql-server-5.1 mysql-server/root_password password $DATABASE_PASSWORD
+mysql-server-5.1 mysql-server/root_password_again password $DATABASE_PASSWORD
+mysql-server-5.1 mysql-server/start_on_boot boolean true
+MYSQL_PRESEED
+    fi
+
+    # while ``.my.cnf`` is not needed for OpenStack to function, it is useful
+    # as it allows you to access the mysql databases via ``mysql nova`` instead
+    # of having to specify the username/password each time.
+    if [[ ! -e $HOME/.my.cnf ]]; then
+        cat <<EOF >$HOME/.my.cnf
+[client]
+user=$DATABASE_USER
+password=$DATABASE_PASSWORD
+host=$DATABASE_HOST
+EOF
+        chmod 0600 $HOME/.my.cnf
+    fi
+    # Install mysql-server
+    install_package mysql-server
+}
+
+function database_connection_url_mysql {
+    local output=$1
+    local db=$2
+    eval "$output=$BASE_SQL_CONN/$db?charset=utf8"
+}
+
+# Restore xtrace
+$XTRACE
--- a/lib/databases/postgresql
+++ b/lib/databases/postgresql
@ -0,0 +1,70 @@
+# lib/postgresql
+# Functions to control the configuration and operation of the PostgreSQL database backend
+
+# Dependencies:
+# DATABASE_{HOST,USER,PASSWORD} must be defined
+
+# Save trace setting
+XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+register_database postgresql
+
+function recreate_database_postgresql {
+    local db=$1
+    local charset=$2
+    # Avoid unsightly error when calling dropdb when the database doesn't exist
+    psql -h$DATABASE_HOST -U$DATABASE_USER -dtemplate1 -c "DROP DATABASE IF EXISTS $db"
+    createdb -h $DATABASE_HOST -U$DATABASE_USER -l C -T template0 -E $charset $db
+}
+
+function configure_database_postgresql {
+    echo_summary "Configuring and starting PostgreSQL"
+    if [[ "$os_PACKAGE" = "rpm" ]]; then
+        PG_HBA=/var/lib/pgsql/data/pg_hba.conf
+        PG_CONF=/var/lib/pgsql/data/postgresql.conf
+    else
+        PG_DIR=`find /etc/postgresql -name pg_hba.conf|xargs dirname`
+        PG_HBA=$PG_DIR/pg_hba.conf
+        PG_CONF=$PG_DIR/postgresql.conf
+    fi
+    sudo [ -e /var/lib/pgsql/data ] || sudo postgresql-setup initdb
+    # Listen on all addresses
+    sudo sed -i "/listen_addresses/s/.*/listen_addresses = '*'/" $PG_CONF
+    # Do password auth from all IPv4 clients
+    sudo sed -i "/^host/s/all\s\+127.0.0.1\/32\s\+ident/$DATABASE_USER\t0.0.0.0\/0\tpassword/" $PG_HBA
+    # Do password auth for all IPv6 clients
+    sudo sed -i "/^host/s/all\s\+::1\/128\s\+ident/$DATABASE_USER\t::0\/0\tpassword/" $PG_HBA
+    start_service postgresql
+
+    # If creating the role fails, chances are it already existed. Try to alter it.
+    sudo -u postgres -i psql -c "CREATE ROLE $DATABASE_USER WITH SUPERUSER LOGIN PASSWORD '$DATABASE_PASSWORD'" || \
+    sudo -u postgres -i psql -c "ALTER ROLE $DATABASE_USER WITH SUPERUSER LOGIN PASSWORD '$DATABASE_PASSWORD'"
+}
+
+function install_database_postgresql {
+    echo_summary "Installing postgresql"
+    PGPASS=$HOME/.pgpass
+    if [[ ! -e $PGPASS ]]; then
+        cat <<EOF > $PGPASS
+*:*:*:$DATABASE_USER:$DATABASE_PASSWORD
+EOF
+        chmod 0600 $PGPASS
+    else
+        sed -i "s/:root:\w\+/:root:$DATABASE_PASSWORD/" $PGPASS
+    fi
+    if [[ "$os_PACKAGE" = "rpm" ]]; then
+        install_package postgresql-server
+    else
+        install_package postgresql
+    fi
+}
+
+function database_connection_url_postgresql {
+    local output=$1
+    local db=$2
+    eval "$output=$BASE_SQL_CONN/$db?client_encoding=utf8"
+}
+
+# Restore xtrace
+$XTRACE
--- a/lib/glance
+++ b/lib/glance
@ -81,7 +81,9 @@ function configure_glance() {
    cp $GLANCE_DIR/etc/glance-registry.conf $GLANCE_REGISTRY_CONF
    iniset $GLANCE_REGISTRY_CONF DEFAULT debug True
    inicomment $GLANCE_REGISTRY_CONF DEFAULT log_file
-    iniset $GLANCE_REGISTRY_CONF DEFAULT sql_connection $BASE_SQL_CONN/glance?charset=utf8
+    local dburl
+    database_connection_url dburl glance
+    iniset $GLANCE_REGISTRY_CONF DEFAULT sql_connection $dburl
    iniset $GLANCE_REGISTRY_CONF DEFAULT use_syslog $SYSLOG
    iniset $GLANCE_REGISTRY_CONF paste_deploy flavor keystone
    iniset $GLANCE_REGISTRY_CONF keystone_authtoken auth_host $KEYSTONE_AUTH_HOST
@ -95,7 +97,7 @@ function configure_glance() {
    cp $GLANCE_DIR/etc/glance-api.conf $GLANCE_API_CONF
    iniset $GLANCE_API_CONF DEFAULT debug True
    inicomment $GLANCE_API_CONF DEFAULT log_file
-    iniset $GLANCE_API_CONF DEFAULT sql_connection $BASE_SQL_CONN/glance?charset=utf8
+    iniset $GLANCE_API_CONF DEFAULT sql_connection $dburl
    iniset $GLANCE_API_CONF DEFAULT use_syslog $SYSLOG
    iniset $GLANCE_API_CONF DEFAULT filesystem_store_datadir $GLANCE_IMAGE_DIR/
    iniset $GLANCE_API_CONF DEFAULT image_cache_dir $GLANCE_CACHE_DIR/
@ -149,8 +151,7 @@ function init_glance() {
    mkdir -p $GLANCE_CACHE_DIR

    # (re)create glance database
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS glance;'
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE glance CHARACTER SET utf8;'
+    recreate_database glance utf8

    $GLANCE_BIN_DIR/glance-manage db_sync
 }
--- a/lib/heat
+++ b/lib/heat
@ -120,7 +120,9 @@ function configure_heat() {
    iniset $HEAT_ENGINE_CONF DEFAULT use_syslog $SYSLOG
    iniset $HEAT_ENGINE_CONF DEFAULT bind_host $HEAT_ENGINE_HOST
    iniset $HEAT_ENGINE_CONF DEFAULT bind_port $HEAT_ENGINE_PORT
-    iniset $HEAT_ENGINE_CONF DEFAULT sql_connection $BASE_SQL_CONN/heat?charset=utf8
+    local dburl
+    database_connection_url dburl heat
+    iniset $HEAT_ENGINE_CONF DEFAULT sql_connection $dburl
    iniset $HEAT_ENGINE_CONF DEFAULT auth_encryption_key `hexdump -n 16 -v -e '/1 "%02x"' /dev/random`

    if is_service_enabled rabbit; then
@ -185,8 +187,7 @@ function configure_heat() {
 function init_heat() {

    # (re)create heat database
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS heat;'
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE heat CHARACTER SET utf8;'
+    recreate_database heat utf8

    $HEAT_DIR/bin/heat-db-setup $os_PACKAGE -r $MYSQL_PASSWORD
    $HEAT_DIR/tools/nova_create_flavors.sh
--- a/lib/keystone
+++ b/lib/keystone
@ -82,9 +82,11 @@ function configure_keystone() {
    fi

    # Rewrite stock ``keystone.conf``
+    local dburl
+    database_connection_url dburl keystone
    iniset $KEYSTONE_CONF DEFAULT admin_token "$SERVICE_TOKEN"
    iniset $KEYSTONE_CONF signing token_format "$KEYSTONE_TOKEN_FORMAT"
-    iniset $KEYSTONE_CONF sql connection "$BASE_SQL_CONN/keystone?charset=utf8"
+    iniset $KEYSTONE_CONF sql connection $dburl
    iniset $KEYSTONE_CONF ec2 driver "keystone.contrib.ec2.backends.sql.Ec2"
    sed -e "
        /^pipeline.*ec2_extension crud_/s|ec2_extension crud_extension|ec2_extension s3_extension crud_extension|;
@ -141,8 +143,7 @@ function configure_keystone() {
 # init_keystone() - Initialize databases, etc.
 function init_keystone() {
    # (Re)create keystone database
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS keystone;'
-    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE keystone CHARACTER SET utf8;'
+    recreate_database keystone utf8

    # Initialize keystone database
    $KEYSTONE_DIR/bin/keystone-manage db_sync
--- a/lib/nova
+++ b/lib/nova
@ -296,7 +296,9 @@ function create_nova_conf() {
    add_nova_opt "s3_port=$S3_SERVICE_PORT"
    add_nova_opt "osapi_compute_extension=nova.api.openstack.compute.contrib.standard_extensions"
    add_nova_opt "my_ip=$HOST_IP"
-    add_nova_opt "sql_connection=$BASE_SQL_CONN/nova?charset=utf8"
+    local dburl
+    database_connection_url dburl nova
+    add_nova_opt "sql_connection=$dburl"
    add_nova_opt "libvirt_type=$LIBVIRT_TYPE"
    add_nova_opt "libvirt_cpu_mode=none"
    add_nova_opt "instance_name_template=${INSTANCE_NAME_PREFIX}%08x"
@ -372,14 +374,12 @@ function init_nova() {
    # All nova components talk to a central database.  We will need to do this step
    # only once for an entire cluster.

-    if is_service_enabled mysql && is_service_enabled nova; then
+    if is_service_enabled $DATABASE_BACKENDS && is_service_enabled nova; then
        # (Re)create nova database
-        mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'DROP DATABASE IF EXISTS nova;'
-
        # Explicitly use latin1: to avoid lp#829209, nova expects the database to
        # use latin1 by default, and then upgrades the database to utf8 (see the
        # 082_essex.py in nova)
-        mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e 'CREATE DATABASE nova CHARACTER SET latin1;'
+        recreate_database nova latin1

        # (Re)create nova database
        $NOVA_BIN_DIR/nova-manage db sync
--- a/stack.sh
+++ b/stack.sh
@ -30,6 +30,8 @@ source $TOP_DIR/functions
 # and ``DISTRO``
 GetDistro

+# Import database library (must be loaded before stackrc which sources localrc)
+source $TOP_DIR/lib/database

 # Settings
 # ========
@ -37,15 +39,15 @@ GetDistro
 # ``stack.sh`` is customizable through setting environment variables.  If you
 # want to override a setting you can set and export it::
 #
-#     export MYSQL_PASSWORD=anothersecret
+#     export DATABASE_PASSWORD=anothersecret
 #     ./stack.sh
 #
-# You can also pass options on a single line ``MYSQL_PASSWORD=simple ./stack.sh``
+# You can also pass options on a single line ``DATABASE_PASSWORD=simple ./stack.sh``
 #
 # Additionally, you can put any local variables into a ``localrc`` file::
 #
-#     MYSQL_PASSWORD=anothersecret
-#     MYSQL_USER=hellaroot
+#     DATABASE_PASSWORD=anothersecret
+#     DATABASE_USER=hellaroot
 #
 # We try to have sensible defaults, so you should be able to run ``./stack.sh``
 # in most cases.  ``localrc`` is not distributed with DevStack and will never
@ -471,24 +473,21 @@ FLAT_INTERFACE=${FLAT_INTERFACE-$GUEST_INTERFACE_DEFAULT}
 # With Quantum networking the NET_MAN variable is ignored.


-# MySQL & (RabbitMQ or Qpid)
+# Database configuration
+# ----------------------
+# To select between database backends, add a line to localrc like:
+#
+#  use_database postgresql
+#
+# The available database backends are defined in the DATABASE_BACKENDS
+# variable defined in stackrc. By default, MySQL is enabled as the database
+# backend.
+
+initialize_database_backends && echo "Using $DATABASE_TYPE database backend" || echo "No database enabled"
+
+# RabbitMQ or Qpid
 # --------------------------

-# We configure Nova, Horizon, Glance and Keystone to use MySQL as their
-# database server.  While they share a single server, each has their own
-# database and tables.
-
-# By default this script will install and configure MySQL.  If you want to
-# use an existing server, you can pass in the user/password/host parameters.
-# You will need to send the same ``MYSQL_PASSWORD`` to every host if you are doing
-# a multi-node DevStack installation.
-MYSQL_HOST=${MYSQL_HOST:-localhost}
-MYSQL_USER=${MYSQL_USER:-root}
-read_password MYSQL_PASSWORD "ENTER A PASSWORD TO USE FOR MYSQL."
-
-# NOTE: Don't specify ``/db`` in this string so we can use it for multiple services
-BASE_SQL_CONN=${BASE_SQL_CONN:-mysql://$MYSQL_USER:$MYSQL_PASSWORD@$MYSQL_HOST}
-
 # Rabbit connection info
 if is_service_enabled rabbit; then
    RABBIT_HOST=${RABBIT_HOST:-localhost}
@ -746,32 +745,8 @@ elif is_service_enabled zeromq; then
    fi
 fi

-if is_service_enabled mysql; then
-
-    if [[ "$os_PACKAGE" = "deb" ]]; then
-        # Seed configuration with mysql password so that apt-get install doesn't
-        # prompt us for a password upon install.
-        cat <<MYSQL_PRESEED | sudo debconf-set-selections
-mysql-server-5.1 mysql-server/root_password password $MYSQL_PASSWORD
-mysql-server-5.1 mysql-server/root_password_again password $MYSQL_PASSWORD
-mysql-server-5.1 mysql-server/start_on_boot boolean true
-MYSQL_PRESEED
-    fi
-
-    # while ``.my.cnf`` is not needed for OpenStack to function, it is useful
-    # as it allows you to access the mysql databases via ``mysql nova`` instead
-    # of having to specify the username/password each time.
-    if [[ ! -e $HOME/.my.cnf ]]; then
-        cat <<EOF >$HOME/.my.cnf
-[client]
-user=$MYSQL_USER
-password=$MYSQL_PASSWORD
-host=$MYSQL_HOST
-EOF
-        chmod 0600 $HOME/.my.cnf
-    fi
-    # Install mysql-server
-    install_package mysql-server
+if is_service_enabled $DATABASE_BACKENDS; then
+    install_database
 fi

 if is_service_enabled horizon; then
@ -993,46 +968,10 @@ elif is_service_enabled qpid; then
 fi


-# Mysql
-# -----
-
-if is_service_enabled mysql; then
-    echo_summary "Configuring and starting MySQL"
-
-    if [[ "$os_PACKAGE" = "deb" ]]; then
-        MY_CONF=/etc/mysql/my.cnf
-        MYSQL=mysql
-    else
-        MY_CONF=/etc/my.cnf
-        MYSQL=mysqld
-    fi
-
-    # Start mysql-server
-    if [[ "$os_PACKAGE" = "rpm" ]]; then
-        # RPM doesn't start the service
-        start_service $MYSQL
-        # Set the root password - only works the first time
-        sudo mysqladmin -u root password $MYSQL_PASSWORD || true
-    fi
-    # Update the DB to give user ‘$MYSQL_USER’@’%’ full control of the all databases:
-    sudo mysql -uroot -p$MYSQL_PASSWORD -h127.0.0.1 -e "GRANT ALL PRIVILEGES ON *.* TO '$MYSQL_USER'@'%' identified by '$MYSQL_PASSWORD';"
-
-    # Now update ``my.cnf`` for some local needs and restart the mysql service
-
-    # Change ‘bind-address’ from localhost (127.0.0.1) to any (0.0.0.0)
-    sudo sed -i '/^bind-address/s/127.0.0.1/0.0.0.0/g' $MY_CONF
-
-    # Set default db type to InnoDB
-    if sudo grep -q "default-storage-engine" $MY_CONF; then
-        # Change it
-        sudo bash -c "source $TOP_DIR/functions; iniset $MY_CONF mysqld default-storage-engine InnoDB"
-    else
-        # Add it
-        sudo sed -i -e "/^\[mysqld\]/ a \
-default-storage-engine = InnoDB" $MY_CONF
-    fi
-
-    restart_service $MYSQL
+# Configure database
+# ------------------
+if is_service_enabled $DATABASE_BACKENDS; then
+    configure_database
 fi

 if [ -z "$SCREEN_HARDSTATUS" ]; then
@ -1283,7 +1222,9 @@ if is_service_enabled quantum; then
    Q_PLUGIN_CONF_FILE=$Q_PLUGIN_CONF_PATH/$Q_PLUGIN_CONF_FILENAME
    cp $QUANTUM_DIR/$Q_PLUGIN_CONF_FILE /$Q_PLUGIN_CONF_FILE

-    iniset /$Q_PLUGIN_CONF_FILE DATABASE sql_connection mysql:\/\/$MYSQL_USER:$MYSQL_PASSWORD@$MYSQL_HOST\/$Q_DB_NAME?charset=utf8
+    database_connection_url dburl $Q_DB_NAME
+    iniset /$Q_PLUGIN_CONF_FILE DATABASE sql_connection $dburl
+    unset dburl

    Q_CONF_FILE=/etc/quantum/quantum.conf
    cp $QUANTUM_DIR/etc/quantum.conf $Q_CONF_FILE
@ -1309,12 +1250,11 @@ if is_service_enabled q-svc; then
    cp $QUANTUM_DIR/etc/api-paste.ini $Q_API_PASTE_FILE
    cp $QUANTUM_DIR/etc/policy.json $Q_POLICY_FILE

-    if is_service_enabled mysql; then
-            mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e "DROP DATABASE IF EXISTS $Q_DB_NAME;"
-            mysql -u$MYSQL_USER -p$MYSQL_PASSWORD -e "CREATE DATABASE IF NOT EXISTS $Q_DB_NAME CHARACTER SET utf8;"
-        else
-            echo "mysql must be enabled in order to use the $Q_PLUGIN Quantum plugin."
-            exit 1
+    if is_service_enabled $DATABASE_BACKENDS; then
+        recreate_database $Q_DB_NAME utf8
+    else
+        echo "A database must be enabled in order to use the $Q_PLUGIN Quantum plugin."
+        exit 1
    fi

    # Update either configuration file with plugin
@ -1974,7 +1914,7 @@ if is_service_enabled q-svc; then
        fi
   fi

-elif is_service_enabled mysql && is_service_enabled nova; then
+elif is_service_enabled $DATABASE_BACKENDS && is_service_enabled nova; then
    # Create a small network
    $NOVA_BIN_DIR/nova-manage network create "$PRIVATE_NETWORK_NAME" $FIXED_RANGE 1 $FIXED_NETWORK_SIZE $NETWORK_CREATE_ARGS

--- a/unstack.sh
+++ b/unstack.sh
@ -15,6 +15,9 @@ TOP_DIR=$(cd $(dirname "$0") && pwd)
 # Import common functions
 source $TOP_DIR/functions

+# Import database library
+source $TOP_DIR/lib/database
+
 # Load local configuration
 source $TOP_DIR/stackrc

@ -102,6 +105,10 @@ if [[ -n "$UNSTACK_ALL" ]]; then
        stop_service mysql
    fi

+    if is_service_enabled postgresql; then
+        stop_service postgresql
+    fi
+
    # Stop rabbitmq-server
    if is_service_enabled rabbit; then
        stop_service rabbitmq-server