refactor zookeeper into a slightly more generic dlm module

This attempts to make the zookeeper installation a bit more modular
(assuming that other folks will want to add other dlms as plugins),
and addresses the service start issues with zookeeper under
ubuntu/upstart.

Zookeeper is not going to be installed by default. Services need to
ask for it with use_dlm.

Change-Id: I33525e2b83a4497a57ec95f62880e0308c88b34f

lib/dlm

@@ -0,0 +1,108 @@
+#!/bin/bash
+#
+# lib/dlm
+#
+# Functions to control the installation and configuration of software
+# that provides a dlm (and possibly other functions). The default is
+# **zookeeper**, and is going to be the only backend supported in the
+# devstack tree.
+
+# Dependencies:
+#
+# - ``functions`` file
+
+# ``stack.sh`` calls the entry points in this order:
+#
+# - is_dlm_enabled
+# - install_dlm
+# - configure_dlm
+# - cleanup_dlm
+
+# Save trace setting
+XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+
+# Defaults
+# --------
+
+# <define global variables here that belong to this project>
+
+# Set up default directories
+ZOOKEEPER_DATA_DIR=$DEST/data/zookeeper
+ZOOKEEPER_CONF_DIR=/etc/zookeeper
+
+
+# Entry Points
+# ------------
+#
+# NOTE(sdague): it is expected that when someone wants to implement
+# another one of these out of tree, they'll implement the following
+# functions:
+#
+# - dlm_backend
+# - install_dlm
+# - configure_dlm
+# - cleanup_dlm
+
+# This should be declared in the settings file of any plugin or
+# service that needs to have a dlm in their enviroment.
+function use_dlm {
+    enable_service $(dlm_backend)
+}
+
+# A function to return the name of the backend in question, some users
+# are going to need to know this.
+function dlm_backend {
+    echo "zookeeper"
+}
+
+# Test if a dlm is enabled (defaults to a zookeeper specific check)
+function is_dlm_enabled {
+    [[ ,${ENABLED_SERVICES}, =~ ,"$(dlm_backend)", ]] && return 0
+    return 1
+}
+
+# cleanup_dlm() - Remove residual data files, anything left over from previous
+# runs that a clean run would need to clean up
+function cleanup_dlm {
+    # NOTE(sdague): we don't check for is_enabled here because we
+    # should just delete this regardless. Some times users updated
+    # their service list before they run cleanup.
+    sudo rm -rf $ZOOKEEPER_DATA_DIR
+}
+
+# configure_dlm() - Set config files, create data dirs, etc
+function configure_dlm {
+    if is_dlm_enabled; then
+        sudo cp $FILES/zookeeper/* $ZOOKEEPER_CONF_DIR
+        sudo sed -i -e 's|.*dataDir.*|dataDir='$ZOOKEEPER_DATA_DIR'|' $ZOOKEEPER_CONF_DIR/zoo.cfg
+        # clean up from previous (possibly aborted) runs
+        # create required data files
+        sudo rm -rf $ZOOKEEPER_DATA_DIR
+        sudo mkdir -p $ZOOKEEPER_DATA_DIR
+        # restart after configuration, there is no reason to make this
+        # another step, because having data files that don't match the
+        # zookeeper running is just going to cause tears.
+        restart_service zookeeper
+    fi
+}
+
+# install_dlm() - Collect source and prepare
+function install_dlm {
+    if is_dlm_enabled; then
+        if is_ubuntu; then
+            install_package zookeeperd
+        else
+            die $LINENO "Don't know how to install zookeeper on this platform"
+        fi
+    fi
+}
+
+# Restore xtrace
+$XTRACE
+
+# Tell emacs to use shell-script-mode
+## Local variables:
+## mode: shell-script
+## End:

lib/zookeeper

@@ -1,91 +0,0 @@
-#!/bin/bash
-#
-# lib/zookeeper
-# Functions to control the installation and configuration of **zookeeper**
-
-# Dependencies:
-#
-# - ``functions`` file
-
-# ``stack.sh`` calls the entry points in this order:
-#
-# - is_zookeeper_enabled
-# - install_zookeeper
-# - configure_zookeeper
-# - init_zookeeper
-# - start_zookeeper
-# - stop_zookeeper
-# - cleanup_zookeeper
-
-# Save trace setting
-XTRACE=$(set +o | grep xtrace)
-set +o xtrace
-
-
-# Defaults
-# --------
-
-# <define global variables here that belong to this project>
-
-# Set up default directories
-ZOOKEEPER_DATA_DIR=$DEST/data/zookeeper
-ZOOKEEPER_CONF_DIR=/etc/zookeeper
-
-
-# Entry Points
-# ------------
-
-# Test if any zookeeper service us enabled
-# is_zookeeper_enabled
-function is_zookeeper_enabled {
-    [[ ,${ENABLED_SERVICES}, =~ ,"zookeeper", ]] && return 0
-    return 1
-}
-
-# cleanup_zookeeper() - Remove residual data files, anything left over from previous
-# runs that a clean run would need to clean up
-function cleanup_zookeeper {
-    sudo rm -rf $ZOOKEEPER_DATA_DIR
-}
-
-# configure_zookeeper() - Set config files, create data dirs, etc
-function configure_zookeeper {
-    sudo cp $FILES/zookeeper/* $ZOOKEEPER_CONF_DIR
-    sudo sed -i -e 's|.*dataDir.*|dataDir='$ZOOKEEPER_DATA_DIR'|' $ZOOKEEPER_CONF_DIR/zoo.cfg
-}
-
-# init_zookeeper() - Initialize databases, etc.
-function init_zookeeper {
-    # clean up from previous (possibly aborted) runs
-    # create required data files
-    sudo rm -rf $ZOOKEEPER_DATA_DIR
-    sudo mkdir -p $ZOOKEEPER_DATA_DIR
-}
-
-# install_zookeeper() - Collect source and prepare
-function install_zookeeper {
-    install_package zookeeperd
-}
-
-# start_zookeeper() - Start running processes, including screen
-function start_zookeeper {
-    # Starting twice Zookeeper on Ubuntu exits with error code 1. See LP#1513741
-    # Match both systemd and sysvinit output
-    local running="(active \(running\)|start/running)"
-    if ! is_ubuntu || ! sudo /usr/sbin/service zookeeper status | egrep -q "$running"; then
-        start_service zookeeper
-    fi
-}
-
-# stop_zookeeper() - Stop running processes (non-screen)
-function stop_zookeeper {
-    stop_service zookeeper
-}
-
-# Restore xtrace
-$XTRACE
-
-# Tell emacs to use shell-script-mode
-## Local variables:
-## mode: shell-script
-## End:

stack.sh

@@ -539,7 +539,7 @@ source $TOP_DIR/lib/heat
 source $TOP_DIR/lib/neutron-legacy
 source $TOP_DIR/lib/ldap
 source $TOP_DIR/lib/dstat
-source $TOP_DIR/lib/zookeeper
+source $TOP_DIR/lib/dlm
 
 # Extras Source
 # --------------
@@ -724,11 +724,10 @@ run_phase stack pre-install
 
 install_rpc_backend
 
-if is_service_enabled zookeeper; then
+# NOTE(sdague): dlm install is conditional on one being enabled by configuration
-    cleanup_zookeeper
+install_dlm
-    configure_zookeeper
+configure_dlm
-    init_zookeeper
+
-fi
 if is_service_enabled $DATABASE_BACKENDS; then
     install_database
 fi
@@ -968,15 +967,6 @@ save_stackenv $LINENO
 start_dstat
 
 
-# Zookeeper
-# -----
-
-# zookeeper for use with tooz for Distributed Lock Management capabilities etc.,
-if is_service_enabled zookeeper; then
-    start_zookeeper
-fi
-
-
 # Keystone
 # --------
 

stackrc

@@ -69,7 +69,7 @@ if ! isset ENABLED_SERVICES ; then
     # Dashboard
     ENABLED_SERVICES+=,horizon
     # Additional services
-    ENABLED_SERVICES+=,rabbit,tempest,mysql,dstat,zookeeper
+    ENABLED_SERVICES+=,rabbit,tempest,mysql,dstat
 fi
 
 # SQLAlchemy supports multiple database drivers for each database server

unstack.sh

@@ -69,7 +69,7 @@ source $TOP_DIR/lib/heat
 source $TOP_DIR/lib/neutron-legacy
 source $TOP_DIR/lib/ldap
 source $TOP_DIR/lib/dstat
-source $TOP_DIR/lib/zookeeper
+source $TOP_DIR/lib/dlm
 
 # Extras Source
 # --------------