From 708e11c13ac25e1db5a4552db699a652f4e32353 Mon Sep 17 00:00:00 2001

From: Michele Baldessari <michele@acksyn.org>

Date: Thu, 7 Sep 2017 18:56:24 +0200

Subject: [PATCH 1/2] Introduce helper functions for container-attribute-target

In this change we introduce the ocf_attribute_target() function that helps

RAs decide where to store per-node attributes. The rationale is that

when an OCF resource runs in a bundle (e.g. rabbitmq-bundle-0) the

NODENAME will point to the bundle name and not to the physical node

running the bundle. Since a bundle can run on any cluster node, this

is not ideal in the situations in which an RA wants to remember on which

*host* a bundle was running (this is typically the case when there is no

shared storage)

The way this new ocf_attribute_target() function works is the following:

A) When the meta-attr 'container-attribute-target' == 'host' and the

   function is called without arguments it will return the physical

   hostname the resource is running on.

B) When the meta-attr 'container-attribute-target' != 'host' and the

   function is called without arguments it will return the NODENAME

   (default)

C) When the meta-attr 'container-attribute-target' == 'host' and the

   function is called with an argument it will return the physical

   hostname on which the corresponding argument is running on.

D) When the meta-attr 'container-attribute-target' != 'host' and the

   function is called with an argument it will return the NODENAME

   (default)

The basic idea is that if resources need to store per-host attributes

you will set the meta attribute 'container-attribute-target' equal to

host (the no-shared storage case). If resources need to store attributes

on a per-bundle basis (because they access data from shared-storage)

then no change is needed on meta attributes (this is the default

behaviour).

Signed-off-by: Andrew Beekhof <abeekhof@redhat.com>

Tested-by: Michele Baldessari <michele@acksyn.org>

Tested-by: Damien Ciabrini <dciabrin@redhat.com>

---

 heartbeat/ocf-shellfuncs.in | 38 ++++++++++++++++++++++++++++++++++++++

 1 file changed, 38 insertions(+)

diff --git a/heartbeat/ocf-shellfuncs.in b/heartbeat/ocf-shellfuncs.in

index 9b6b99f88a56..ddd6854e9487 100644

--- a/heartbeat/ocf-shellfuncs.in

+++ b/heartbeat/ocf-shellfuncs.in

@@ -989,6 +989,44 @@ ocf_stop_trace() {

 	set +x

 }

+# Helper functions to map from nodename/bundle-name and physical hostname

+# list_index_for_word "node0 node1 node2 node3 node4 node5" node4 --> 5

+# list_word_at_index "NA host1 host2 host3 host4 host5" 3      --> host2

+

+# list_index_for_word "node1 node2 node3 node4 node5" node7 --> ""

+# list_word_at_index "host1 host2 host3 host4 host5" 8      --> ""

+

+# attribute_target node1                                    --> host1

+list_index_for_word() {

+	echo $1 | tr ' ' '\n' | awk -v x="$2" '$0~x {print NR}'

+}

+

+list_word_at_index() {

+	echo $1 | tr ' ' '\n' | awk -v n="$2" 'n == NR'

+}

+

+ocf_attribute_target() {

+	if [ x$1 = x ]; then

+		if [ x$OCF_RESKEY_CRM_meta_container_attribute_target = xhost -a x$OCF_RESKEY_CRM_meta_physical_host != x ]; then

+			echo $OCF_RESKEY_CRM_meta_physical_host

+		else

+			echo $OCF_RESKEY_CRM_meta_on_node

+		fi

+		return

+	elif [ x"$OCF_RESKEY_CRM_meta_notify_all_uname" != x ]; then

+		index=$(list_index_for_word "$OCF_RESKEY_CRM_meta_notify_all_uname" $1)

+		mapping=""

+		if [ x$index != x ]; then

+			mapping=$(list_word_at_index "$OCF_RESKEY_CRM_meta_notify_all_hosts" $index)

+		fi

+		if [ x$mapping != x -a x$mapping != xNA ]; then

+			echo $mapping

+			return

+		fi

+	fi

+	echo $1

+}

+

 __ocf_set_defaults "$@"

 : ${OCF_TRACE_RA:=$OCF_RESKEY_trace_ra}

-- 

2.13.5