an introduction to openstack heat

Diving intoHeat

Mirantis, 2013Dina Belova

● Orchestration service for OpenStack (officially supports Grizzly release)

● Uses templating mechanism● Controls complex groups of cloud resources● Huge potential and multiple use cases● More than 20 active contributors

What is Heat?

● AWS CloudFormation● TOSCA:

Topology and Orchestration Specification for Cloud Applications

Heat ideas and standards

Stack - group of connected cloud resources (VM, volumes, networks, etc.)

● Autoscaling

● HA mechanism for the different levels (services running inside an instance, individual instances, stacks)

● Nested stacks

Heat basics. Stack

Heat basics. Template

● Stacks are created from templates● Heat templates have the same structure and

abstractions as AWS CloudFormation templates● Resource mapping in the next OpenStack release● Templates are well integrated with Chef and

Puppet

Heat Roadmap (Havanna)

● Parallel source creation● Improve networking / Quantum support● Rollings updates● Support for extended template language● Add AutoScaling API actions● Move to Ceilometer for

metrics / monitoring / alarms

Heat Roadmap (Havanna)

● More improvements for stacks updating● Improved security● Native for OpenStack resource types (resource

mapping)● Add suspend / resume stack actions● Configurable LoadBalancer (LBaaS)

Already in Heat

● Nested stacks● High Availability (HA) for different resource levels● Associate users with templates using Keystone● Get boto (Python programming language

interface to Amazon Web Services) working with Heat

● API rework to align AWS specification

Heat Basic WorkFlow

OpenStackStack

VM VMVM

Heat CLI tools

Heat

DB

Heat API

CloudWatchAPI

Heat Engine

MQ Watcher Task

Scaling Policy

Auto Scaling Group

Heat API

● heat-api (OpenStack native REST API) or heat-api-cfn (provides AWS Query API)

● Communicates with Heat Engine and tells it what actions to do

Heat Engine

● Does all the orchestration work● Layer on which resource integration is

implemented● Contains abstractions to use Auto Scaling and

High Availability

Heat CloudWatch API

● Ideologically refers to AWS CloudWatch service (gets metrics from stacks)

● Will be replaced by Ceilometer● Used for Auto Scaling

Heat CLI tools

● heatclient uses Heat REST API● heat-cfn uses Heat CloudFormation compatible

API (deprecated)

Heat Auto Scaling Principles

● Agents are installed to the VMs. They send VM telemetry to the monitoring component periodically

● Monitoring component (Heat CloudWatch) is responsible for the communication between VMs and Heat

● Core functionality (implemented in Heat Engine) provides the scaling itself

Installation

● Heat + DevStack● Heat + Ubuntu ● Heat + Fedora

CLI (Heat Client)

event-list List events for a stack.event-show Describe the event.resource-list Show list of resources belonging to a stack.resource-metadata List resource metadata.resource-show Describe the resource.stack-create Create the stack.stack-delete Delete the stack.stack-list List the user's stacks.stack-show Describe the stack.stack-update Update the stack.template-show Get the template for the specified stack.template-validate Validate a template with parameters.help Display help about this program or one of its subcommands.

Try Heat + DevStack

Launch a stack:heat stack-create teststack

-u <template_to_use> \-P "InstanceType=m1.large; \

DBUsername=wp; \ DBPassword=verybadpassword; \ KeyName=heat_key; \ LinuxDistribution=F17"

Example of template to use address:https://raw.github.com/openstack/heat-templates/master/cfn/WordPress_Single_Instance.template

Get stack's list

heat stack-list

If everything is nice after stack creation+--------------------------------------+------------+-----------------+----------------------+| id | stack_name | stack_status | creation_time |+--------------------------------------+------------+-----------------+----------------------+| 70296f8e-f301-465f-8b42-1aa3f95c42f6 | teststack | CREATE_COMPLETE | 2013-05-29T07:39:57Z |+--------------------------------------+------------+-----------------+----------------------+

If something goes wrong+--------------------------------------+------------+---------------+----------------------+| id | stack_name | stack_status | creation_time |+--------------------------------------+------------+---------------+----------------------+| 70296f8e-f301-465f-8b42-1aa3f95c42f6 | teststack | CREATE_FAILED | 2013-05-29T07:39:57Z |+--------------------------------------+------------+---------------+----------------------+

Delete stack

heat stack-delete 70296f8e-f301-465f-8b42-1aa3f95c42f6

+--------------------------------------+------------+--------------------+----------------------+| id | stack_name | stack_status | creation_time |+--------------------------------------+------------+--------------------+----------------------+| 70296f8e-f301-465f-8b42-1aa3f95c42f6 | teststack | DELETE_IN_PROGRESS | 2013-05-29T07:38:11Z |+--------------------------------------+------------+--------------------+----------------------+

Template structure

● Description● Parameters● Mappings● Resources● Outputs

{ "AWSTemplateFormatVersion" : "version date",

"Description" : "Valid JSON strings up to 4K",

"Parameters" : { set of parameters }, "Mappings" : { set of mappings }, "Resources" : { set of resources },

"Outputs" : { set of outputs }}

Template elements example

Description"Description" : "Template to test something important"

Parameters"Parameters": {

"InstanceType" : {"Description" : "Test instance type",

"Type" : "String", "Default" : "m1.small", "AllowedValues" : ["m1.small", "m1.medium"] }}

Template elements example

Mappings "Mappings" : {

"AWSInstanceType2Arch" : {"m1.tiny" : { "Arch" : "32" },

"m1.small" : { "Arch" : "64" }, "m1.medium" : { "Arch" : "64" }, "m1.large" : { "Arch" : "64" }, "m1.xlarge" : { "Arch" : "64" } }}

Template elements example

Resources "Resources" : { "network": { "Type": "OS::Quantum::Net", "Properties": { "name": "the_network" } },

"unnamed_network": { "Type": "OS::Quantum::Net" },}

Template elements example

Outputs"Outputs" : { "the_network_status" : { "Value" : { "Fn::GetAtt" : [ "network", "status" ]}, "Description" : "Status of network" },

"port_device_owner" : { "Value" : { "Fn::GetAtt" : [ "port", "device_owner"]}, "Description" : "Device owner of the port" }}

Useful links

● http://docs.openstack.org/developer/heat/ ● https://wiki.openstack.org/wiki/Heat ● https://github.com/openstack/heat● https://github.com/openstack/heat-templates

Thank you for the attention

www.mirantis.com

dbelova@mirantis.com