How to Develop OpenStack
Download as PPTX, PDF2 likes545 views
The document provides an overview of OpenStack, a cloud operating system that manages compute, storage, and networking resources in data centers. It details various OpenStack services, including compute (Nova), storage (Cinder, Swift), and networking (Neutron), as well as key components of the Nova architecture and communication methods between services. Additionally, it describes the programming languages and libraries used within OpenStack and outlines the process for contributing to the project.
How to Develop OpenStack
- 2. Agenda 2 • OpenStack Services • OpenStack Architecture • Nova Architecture • Start on Codes • Messaging in OpenStack • OpenStack Libraries • Request Flow in OpenStack • OpenStack Clients
- 3. OpenStack is a cloud operating system that controls large pools of compute, storage, and networking resources throughout a datacenter. What is OpenStack 3
- 4. OpenStack Services Dashboard Horizon • web-based portal to interact with underlying OpenStack services NOVA COMPUTE LAYER •Manages the compute instances in an OpenStack environment. Responsibilities include creating , scheduling and decommissioning of virtual machines on demand. KEYSTONE IDENTITY • authentication and authorization service for other OpenStack services 4
- 5. OpenStack Services CINDER BLOCK STORAGE • Provides persistent block storage to running instances SWIFT OBJECT STORAGE •Stores and retrieves arbitrary unstructured data objects via a RESTful, HTTP based API GLANCE IMAGE MANAGEMENT • Stores and retrieves virtual machine disk images 5
- 6. OpenStack Services NEUTRON NETWORKING •Enables Network- Connectivity-as-a-Service for other OpenStack services, such as OpenStack Compute HEAT ORCHESTRATION CEILOMETER TROVE SAHARA 6
- 8. Why Develop OpenStack 8 OpenStack Hypervisor Support Matrix
- 9. First Step 9 You should understand the codes
- 11. Many Teams and Many Projects 11
- 12. NOVA NOVA API 12
- 14. Nova Components Nova-api supports OpenStack Compute API, Amazon's EC2 API communicated over HTTP, converts the requests to components via message queue Nova- conductor provides coordination and database query support for Nova Nova- compute A worker daemon which takes orders from its message queue and perform virtual machine create/delete tasks using Hypervisor's API. 14
- 15. Nova Components Nova- scheduler decides which Nova Compute Host to allot for virtual machine request Nova- network takes network related tasks from its message queue and performing those. OpenStack's neutron component can be opted instead of nova-network. Message queue All components of Nova communicate with each other in a non-blocking callback-oriented manner using AMQP protocol 15
- 16. Clone a repository from: • https://git.openstack.org/openstack/<projectname> • https://github.com/openstack/<projectname> For nova : • https://github.com/openstack/nova • https://git.openstack.org/openstack/nova Starting Work on Code 16
- 17. OpenStack Programming Language You Should Know 17
- 18. Messaging in OpenStack How messages transport in OpenStack ? 18
- 19. Two methods: • OpenStack components such as Nova , Cinder , Neutron communicates internally via AMQP (Advanced Message Queue Protocol) using RabbitMQ or Qpid • Through each other using REST-call. Messaging in OpenStack 19
- 20. The AMQP either RabbitMQ or Qpid, sits between any two Nova components and allows them to communicate using Remote Procedure Calls (RPC ) Message Queue in Nova 20
- 21. Message Queue in Nova • rpc.cast :don’t wait for result • rpc.call : wait for result (when there is something to return) 21
- 22. Messaging Between OpenStack Services 22
- 23. OpenStack Libraries(oslo) The Oslo project intends to produce a python library containing infrastructure code shared by OpenStack projects including : oslo.config oslo.concurrency oslo.utils oslo.serialization oslo.messaging oslo.i18n 23
- 24. OpenStack Libraries(oslo.config) A library for parsing configuration options from the command line and configuration files. 24 Parse the /etc/nova/nova.conf and convert it to cfg object
- 25. oslo.concurrency managing external processes and task synchronization. OpenStack oslo oslo.utils a library that provides various low-level utility modules/code, such as fileutils, timeutils, importutils(import related utilities and helper functions) oslo.messaging The Oslo messaging API supports RPC 25
- 26. Request Flow for Provisioning Instance 26
- 27. OpenStack Clients • Most OpenStack project provides a command-line client for each service including: • python-glanceclient • python-novaclient • python-keystoneclient • … 27
- 28. • nova boot (Create new instance) • nova reboot • nova flavor-list(Print a list of available flavors (sizes of servers)) • nova resize (Resize the instance to new flavor) • …. Nova-client • Nova client is for the Compute service provides a nova command-line client • Nova client is a client for the OpenStack Nova API Some of nova commands: 28
- 29. Write New API in Nova • If you want to write new API in Nova, you should be familiar with nova client as well . • For example nova resize , first shutdown the current instance, then change the flavor and migrate it to the new host which is selected by scheduler. • You should know how to invoke new API by nova client 29
- 30. Resize Instance on the Same Host • Suppose we want to have our own resize instance command which allows to resize an instance on the same host if it is possible(enough resources available) • A solution Check if possible to resize on place If OK, Shutdown the instance Take a snapshot Create a new instance with the new flavor on the same host Boot instance with the snapshot image Delete the old instance 30
- 31. • Many commands in OpenStack novaclient following same process • Suppose Libvirt is used as compute driver Command Flow 31
- 32. • Account Setup: You need a Launchpad account • Join OpenStack Foundation • Log Into Gerrit Review System • Install git • Clone the codes • Working on Bugs How to Contribute in OpenStack 32
- 33. 33
Editor's Notes
- #2: How to develop OpenStack in Deep
- #4: OpenStack is a cloud Operation System
- #5: OpenStack Services including Horizon a web-based Interface Nova manages VMs Keystone is a authentication and authorization service
- #6: Cinder is block storage Swift Stores and retrieves arbitrary unstructured data objects via a RESTful Glance image management
- #7: Neutron networking management And other OpenStack such as Heat, Ceilometer, Trove, Sahara
- #8: OpenStack architecture
- #9: Hypervisor Support Matrix OpenStack Compute (Nova) has an abstraction layer for compute drivers. This is what allows you to choose which hypervisor(s) to use for your Nova deployment. The reality is that the support of each of the options is not equal. They are not tested the same amount. They also do not all support the same features.
- #11: OpenStack code architecture, each component such as Nova, Keystone, Glance, has an API which is responsible to interact with other OpenStack component. Queue is a service for massage transportation in OpenStack NovaDB store information about virtual machines Horizon /CLI is the way a user can intrract with openStack
- #12: There are many teams work on many project in OpenStack,
- #13: We select Nova for work on
- #14: Nova consists of nova-api, nova-compute, nova-db, nova-scheduler, nova conductor, which communicate over queue
- #15: Nova-api supports OpenStack Compute API, Amazon's EC2 API Nova-conductor provides coordination and database query support for Nova Nova-compute Manage wvrtual machines
- #17: Codes of OpenStack exist on git of OpenStack as in github You can clone the nova codes like Git https://github.com/openstack/nova
- #18: Pre requirements involve Python, JSON, Schell Script
- #19: Messaging in OpenStack
- #20: Two methods of message transportation in OpenStack
- #21: Nova components communicate using RPC
- #22: Tow types of RPC is used in OpenStack rpc.cast :don’t wait for result rpc.call : wait for result (when there is something to return)
- #23: Communication between OpenStack services via Restfull
- #24: Oslo is a collection of libraries used by almost every OpenStack projects including :
- #25: Oslo.config is a A library for parsing configuration and convert them to cfg objects
- #27: The request flow for provisioning an Instance goes like this: Dashboard or CLI gets the user credential and does the REST call to Keystone for authentication. Keystone authenticate the credentials and generate & send back auth-token which will be used for sending request to other Components through REST-call. Dashboard or CLI convert the new instance request specified in ‘launch instance’ or ‘nova-boot’ form to REST API request and send it to nova-api. nova-api receive the request and sends the request for validation auth-token and access permission to keystone. Keystone validates the token and sends updated auth headers with roles and permissions. nova-api interacts with nova-database. Creates initial db entry for new instance. nova-api sends the rpc.call request to nova-scheduler excepting to get updated instance entry with host ID specified. nova-scheduler picks the request from the queue. nova-scheduler interacts with nova-database to find an appropriate host via filtering and weighing. Returns the updated instance entry with appropriate host ID after filtering and weighing. nova-scheduler sends the rpc.cast request to nova-compute for ‘launching instance’ on appropriate host . nova-compute picks the request from the queue. nova-compute send the rpc.call request to nova-conductor to fetch the instance information such as host ID and flavor( Ram , CPU ,Disk). nova-conductor picks the request from the queue. nova-conductor interacts with nova-database. Return the instance information. nova-compute picks the instance information from the queue. nova-compute does the REST call by passing auth-token to glance-api to get the Image URI by Image ID from glance and upload image from image storage. glance-api validates the auth-token with keystone. nova-compute get the image metadata. nova-compute does the REST-call by passing auth-token to Network API to allocate and configure the network such that instance gets the IP address. neutron validates the auth-token with keystone. nova-compute get the network info. nova-compute does the REST call by passing auth-token to Volume API to attach volumes to instance. cinder-api validates the auth-token with keystone. nova-compute gets the block storage info. nova-compute generates data for hypervisor driver and executes request on Hypervisor( via libvirt or a
- #32: Request flow
- #33: Gerrit provides web based code review and repository management for the Git version control system Launchpad is an open source suite of tools that help people and teams to work together on software projects