Cosug 2012-lzy
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The document summarizes the source code structure and architecture of OpenStack's Nova compute service. It describes the file structure and main components, using diagrams to illustrate how components like the compute API, network API, and scheduler interact. It also provides an example workflow of allocating a floating IP to an instance. Finally, it discusses how to get involved in contributing to Nova on Launchpad and GitHub.
Cosug 2012-lzy
- 1. Hacking on OpenStack’s Nova Source Code 2012-01-08 Luo, Zhongyue zhongyue@staff.sina.com.cn
- 2. TODO Intro The source code structure of Nova File structure Component architecture An example Contributing Conclusion 2
- 3. Intro What is OpenStack? and Nova? WHY shoud I listen to this? Can we actually hack the code in 30min? Why should I trust this guy? 3
- 4. Source code structure of Nova Macro vs Micro(DIY) File structure Component architecture File structure ↔ Component architecture 4
- 5. But first...terminologies Service Topic Nova component → Service.create(Topic) Manager (abst) ⊂ Nova component Drivers (impl) ⊂ Manager ex) lvm, qemu, xen, hyperV Lazy plugging → Value based module loading AMQP → Advanced Message Queue Protocol API → REST & Inner 5
- 6. File structure ”start” ”configs” ”helpers” ”REST” ”is a topic” ”is a topic” ”is a topic” ”is a topic” 6
- 7. Component architecture Tenant http://nova.openstack.org/nova.concepts.html 7
- 8. Component architecture ”/etc/nova/nova.conf” ”ec2”, ”osapi” 8
- 9. ”network” ? ? 9
- 10. Component structure ”network” Network service Periodic Topic: network task Manager Driver: linux_net Reads message from Queue Returns results back to DB or queue Calls inner APIs Network API Looks up DB Sends message to Service via queue - Cast: Send and forget - Call: Send and wait 10
- 11. Component architecture revisited DB API API Queue API API WSGI 11
- 12. An example Let’s allocate a floating-ip to an instance with a fixed-ip DB ”compute API” API 1 API Queue API Allocate 10.2.3.11 to a-fake-uuid? API Do you have permission? WSGI I wonder if a-fake-uuid exists... I’ll ask compute API. POST /v2/a-fake-tenant/servers/a-fake-uuid/action 12
- 13. An example Yup, a-fake-uuid is valid. Oh, and its fixed-ip is 192.168.0.8. Take it from here network API! 2 DB ”compute API” API 3 API Queue ”network API” API API WSGI 13
- 14. An example ”nova-network” So translate 192.168.0.8 to 10.2.3.11? Go and get your mail. I’ll tell nova-network to run ”associate_floating_ip”. Ok, my casting is done. DB I got a message! Dear manager, ”compute API” ”associate_floating_ip” API 5 API 4 Queue ”network API” API API WSGI 14
- 15. An example ”nova network” 7 iptables 6 DB 192.168.0.8 ↔ 10.2.3.11 DB update...Done. ”compute API” Running iptables-save...Done. API API Queue ”network API” API API WSGI 15
- 16. An example ”nova network” Did the allocation a-fake-uuid: 192.168.0.8 ↔ 10.2.3.11 finish? 2 DB ”compute API” API 3 1 API Queue ”network API” API Here’s the details of a-fake-uuid. 4 API You want to see if the allocation was a success? WSGI I’ll check with compute API... GET /v2/a-fake-tenant/servers/a-fake-uuid 16
- 17. OpenStack Nova architecture ”nova network” ”nova volume” ”nova compute” DB ”compute API” API API ”scheduler API” Queue ”network API” API ”nova scheduler” API WSGI ”volume API” 17
- 18. Contributing LaunchPad http://launchpad.net/~openstack Join mailing lists Documents http://docs.openstack.org/ More info http://wiki.openstack.org/HowToContribute 18
- 19. Conclusion Structure of code and components of Nova An example How to get involved http://github.com/lzyeval/talk-COSUG-2012 http://launchpad.net/~lzyeval 19