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
diff --git a/lib/dlm b/lib/dlm
new file mode 100644
index 0000000..f68ee26
--- /dev/null
+++ b/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: