Hacking on OpenStack\'s Nova source code

Hacking on OpenStack\'s Nova source code

• 1.
  Hacking on OpenStack’s Nova SourceCode 2012-01-08 Luo, Zhongyue zhongyue@staff.sina.com.cn
• 2.
  TODO Intro Thesource 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 structureof 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
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  Component architecture Tenant http://nova.openstack.org/nova.concepts.html 7
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  Component architecture ”/etc/nova/nova.conf” ”ec2”, ”osapi” 8
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  ”network” ? ? 9
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  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
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  Component architecture revisited DB API API Queue API API WSGI 11
• 12.
  An example Let’s allocatea 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
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  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
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  An example ”nova-network” So translate 192.168.0.8 to 10.2.3.11? Go check your mail. I’ll tell nova-network to run ”associate_floating_ip”. Ok, my casting is done. DB I got a message! It says... Dear manager, ”compute API” ”associate_floating_ip” API 5 API 4 Queue ”network API” API API WSGI 14
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  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
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  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
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  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
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  Contributing LaunchPad http://launchpad.net/~openstack Join mailing lists Documents http://docs.openstack.org/ More info http://wiki.openstack.org/HowToContribute 18
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  Conclusion Structure ofcode and components of Nova An example How to get involved http://github.com/lzyeval/talk-COSUG-2012 http://launchpad.net/~lzyeval 19