Bug 1042250

Summary:	[RFE][heat]: Signaling and Coordination
Product:	Red Hat OpenStack	Reporter:	RHOS Integration <rhos-integ>
Component:	RFEs	Assignee:	RHOS Maint <rhos-maint>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	markmc, yeylon
Target Milestone:	---	Keywords:	FutureFeature
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
URL:	https://blueprints.launchpad.net/heat/+spec/signaling-coordination
Whiteboard:	upstream_milestone_none upstream_status_started upstream_definition_drafting
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-03-19 17:27:32 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description RHOS Integration 2013-12-12 21:31:08 UTC

Cloned from launchpad blueprint https://blueprints.launchpad.net/heat/+spec/signaling-coordination.

Description:

Overview

Provide an API or signaling mechanism that will allow resources(instances) to share information between themselves (ex. usernames, passwords). The goal is to have a simple, declarative way of expressing dependencies in HOT templates (as opposed to having explicit WaitCondition/WaitHandle pairs as in current cfn templates) and have the Heat engine do respective orchestration at runtime.
For example, by simply defining a depends_on relation in a HOT template, appropriate signaling should be performed at runtime so that a component A that depends on another component B is processed after component B has been configured.

What is missing/what are we trying to solve:
Currently in Heat there is a gap in configuring complex and larger software systems.  For example sharing a username, password, or database dynamically at deploy time does not exist in Heat right now.  It is possible to accomplish this with cfn signaling but it is messy and complex.  We wish to simply this.

Specification URL (additional information):

None