This document summarizes two template languages for OpenStack - HOT (Heat Orchestration Template) and TOSCA (Topology and Orchestration Standard for Cloud Applications). It describes their histories, similarities in structure, differences in lifecycle support and wiring/validation capabilities. It also discusses how they have mutually influenced each other and projects like a TOSCA to HOT translator and Cloudify that use TOSCA templates with HOT to orchestrate infrastructure. Examples of SugarCRM and NodeCellar applications defined in HOT and TOSCA-like templates are also provided.

1. Template Languages for
OpenStack
Shay Naeh and Yaron Parasol

2. About Us
• Shay Naeh – Senior Solution Architect,
GigaSpaces
• Yaron Parasol – VP of Product, GigaSpaces
– @yaronpar on twitter

3. Meet the Cast
• HOT
– Heat Orchestration Template
– Declarative
– YAML
• TOSCA
– Topology & Orchestration Standard for Cloud
Application
– Declarative & Imperative
– XML and now YAML

4. History
• HOT
– Came to replace Cloud Formation syntax
– Main use case in mind – Infrastructure creation
– Following the Cloud Formation limited model
• TOSCA
– Application centric by design
– Automation of any production process

5. Similarities
• Similar structure:
– Description
– Input parameters
– Components graph
– Output parameters
• Components Design
– Component is an object of type
– It has dependencies on other components
– It has configuration / initial state in the format of
properties

6. Mutual Influences
• TOSCA adopted HOT Input and Output
parameters (coming from Cloud Formation)
• HOT added software_config provider to
describe application stack explicitly
• HOT adopted TOSCA relationship syntax and
semantics

7. Differences
• Lifecycle
– HOT has limited lifecycle events model
• post create hook for installation
– TOSCA using interfaces has lifecycle hooks for node and for relationship node
• Wiring and Validation - Requirements and Capabilities
– HOT doesn’t have wiring beyond explicit relationship and parameters injection
through user data
– TOSCA – has the mechanism of requirements and capabilities for fine grained
wiring and validations
• Support of Workflows
– HOT is 100% declarative. The WF is hardcoded into Heat engine
– TOSCA using interfaces allow for any imperative workflow as the driver of
processes (No hard coded processes)

8. Putting it all together
• TOSCA to HOT translator project:
– Developed outside of stackforge but coming in soon
– Contributors: IBM, GigaSpaces, Huawei and others
– Allow users to describe their stack in TOSCA and use
HEAT
• Cloudify – Holistic approach to application
automation on Openstack
– Uses TOSCA (currently TOSCA like) templates
– Soon to use HEAT to orchestrate infrastructure
– Adds: Monitoring, Log collection, Analytics, workflows

9. DEEP DIVE

10. Topology
Infrastructure
Middleware
Application
Host Host Network
Apache Tomcat MySQL
Mod_proxy WAR Schema

11. TOSCA in a Nutshell

12. Sugar CRM Example

13. HOT
Type
LanguageTypesTemplates
OS::Nova::Server OS::Heat::software_c
onfig
Sugar_CRM_VM Sugar_CRM_App
Sugar_CRM_DB
apache
mySQL
Relationship
Script
Depends_on
Hosted_on
Connects_to

14. TOSCA Input

15. Hot Input

16. TOSCA Node

17. HOT Component & Resource

18. TOSCA Requirements

19. TOSCA Relationship

20. HOT Relationships

21. DEMO

22. Heat Template

23. Heat Topology View

24. Apache Server DB Server
NodeJS
NodeCeller
MongoDB
TOSCA (Like) Example
• App Network
• App Subnet
• App Port
• Security Group
• Apache Floating IP
• Router Gateway
• Data Network
• Data Subnet
• Data Port
• Security Group
Router
Monitoring, Logging CI

25. Network View

26. Topology View

27. TOSCA (Like) Blueprint

28. References
• Wine cellar example
– https://github.com/cloudify-cosmo/cloudify-
nodecellar-openstack
• Cloudify 3
– http://getcloudify.org