From 995c1ee62f8f213ded72fba4782a1c5dbbd51983 Mon Sep 17 00:00:00 2001
From: Bharat Kumar Kobagana <bharat.kobagana@redhat.com>
Date: Thu, 23 Jul 2015 15:40:17 +0530
Subject: [PATCH] devstack-plugin-glusterfs: Adding checks for error conditions

This patch introduces a new configuration parameter (knob)
CONFIGURE_GLUSTERFS_CINDER to enable/disable glusterfs as a
backend for Cinder. And added below error conditions:

* glusterfs plugin enabled but CONFIGURE_GLUSTERFS_CINDER set to
False
* CONFIGURE_GLUSTERFS_CINDER set to True, but CINDER_ENABLED_BACKENDS
doesn't have at least one backend of type glusterfs.

Change-Id: Ic802a2f2bbbdc1af04fd1220d2055be1e853fef8
---
 devstack/gluster-functions.sh |  4 +++-
 devstack/plugin.sh            | 29 +++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/devstack/gluster-functions.sh b/devstack/gluster-functions.sh
index 269a83b..54f1b3d 100644
--- a/devstack/gluster-functions.sh
+++ b/devstack/gluster-functions.sh
@@ -87,7 +87,9 @@ function cleanup_glusterfs {
     local vol_name
 
     # Cleaning up Cinder GlusterFS shares
-    _delete_gluster_shares $CINDER_GLUSTERFS_SHARES
+    if [ "$CONFIGURE_GLUSTERFS_CINDER" = "True" ]; then
+        _delete_gluster_shares $CINDER_GLUSTERFS_SHARES
+    fi
 
     if [[ -e ${GLUSTERFS_DISK_IMAGE} ]]; then
         sudo rm -f ${GLUSTERFS_DISK_IMAGE}
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index af77ed1..a6acdb6 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -19,6 +19,35 @@
 # Defaults
 # --------
 
+# Set CONFIGURE_GLUSTERFS_CINDER to true, to enable GlusterFS as a backend for Cinder.
+CONFIGURE_GLUSTERFS_CINDER=${CONFIGURE_GLUSTERFS_CINDER:-True}
+
+# Error out when devstack-plugin-glusterfs is enabled, but not selected as a backend for cinder.
+if [ "$CONFIGURE_GLUSTERFS_CINDER" = "False" ]; then
+    echo "GlusterFS plugin enabled but not selected as a backend for Cinder."
+    echo "Please set CONFIGURE_GLUSTERFS_CINDER to True in localrc."
+    exit 1
+fi
+
+# When CONFIGURE_GLUSTERFS_CINDER is true, CINDER_ENABLED_BACKENDS should have
+# at least one backend of type 'glusterfs', error out otherwise.
+local is_gluster_backend_configured=False
+for be in ${CINDER_ENABLED_BACKENDS//,/ }; do
+    if [ "${be%%:*}" = "glusterfs" ]; then
+        is_gluster_backend_configured=True
+        break
+    fi
+done
+if [ "$CONFIGURE_GLUSTERFS_CINDER" = "True" ] && [ "$is_gluster_backend_configured" = "False" ]; then
+    echo "CONFIGURE_GLUSTERFS_CINDER is set to True, to configure GlusterFS as a backend for Cinder."
+    echo "But, glusterfs backend type not present in CINDER_ENABLED_BACKENDS."
+    echo "Please enable at least one backend of type glusterfs in CINDER_ENABLED_BACKENDS."
+    exit 1
+elif [ "$CONFIGURE_GLUSTERFS_CINDER" = "False" ] && [ "$is_gluster_backend_configured" = "True" ]; then
+    echo "Configured Glusterfs as backend type in CINDER_ENABLED_BACKENDS. But CONFIGURE_GLUSTERFS_CINDER set to False."
+    exit 1
+fi
+
 # GLUSTERFS_PLUGIN_DIR contains the path to devstack-plugin-glusterfs/devstack directory
 GLUSTERFS_PLUGIN_DIR=$(readlink -f $(dirname ${BASH_SOURCE[0]}))