Docker Internals

Twilio talk - 11/14/2013

Transcript

1. By  Guillaume  J.  Charmes  <guillaume@docker.com>                  @charme_g   Docker  version  0.6.6  /  0.7.0-­‐rc5   Docker Internals SF Docker Meetup at Twilio ##dockermeetup   11/14/2013  
2. This is your last chance 1.  Isolation 2.  Images 3.  Process Management 4.  Roadmap
3. Isolation •  LXC •  Cgroups/Namespaces •  Processes •  Mounts •  Network •  Network •  NAT (DOCKER chain) •  Expose / Links •  File System •  Chroot on steroids
4. Isolation •  Isolation: Namespaces •  Only 1 syscall (setns()). No hypervisor •  Mounts, Uts (hostname), Net, Pid, IPC, User •  Resource management: Cgroups •  Memory Limitation •  CPU Shares •  Future: blkio
5. Isolation •  Network •  Bridge •  Veth •  NAT •  Expose / Links •  File System •  Chroot++ •  Image management
6. 1.  Isolation 2.  Images 3.  Process Management 4.  Roadmap
7. Images •  AUFS •  Image format •  Base image •  Layer + parent id •  Whiteouts (.wh.) •  Difference Image vs Container •  Registry •  Future •  Devicemapper •  Backend interface
8. Images •  Why AUFS? •  Production usage for years •  Layers •  Multiple RO layers, 1 RW -> Diff •  Limitations •  42 layers •  Whiteouts •  Deletion management
9. Images •  Image format •  Payload (layer) •  Metadata (parent id) •  Image vs Container •  Differences •  Future: Unified format
10. Images •  Image sharing: Registry •  Push/Pull via diffs •  Future •  Backend interface / Devicemapper •  Unified image format: whiteouts (.wh.)
11. 1.  Isolation 2.  Images 3.  Process Management 4.  Roadmap
12. •  Docker daemon •  Transports unix/tcp internals •  Attach logic •  Logs •  Host Integration •  Dockerfile •  RUN •  EXPOSE •  What is the Context? •  Service Discovery docker  run   Process Management
13. •  Docker daemon •  Transports: •  Holds all containers •  Handles the logging •  Docker client •  Everything uses the Remote API docker  –d  –H  tcp://127.0.0.1:4243  –H  unix:///var/run/docker.sock   Process Management
14. Process Management internals •  Create •  Start •  Attach •  General Config vs Host Config •  Attach protocol •  TTY •  Non-TTY docker    run  
15. 1.  Isolation 2.  Images 3.  Process Management 4.  Roadmap
16. Roadmap •  Docker 0.7 •  File system backend interface •  Docker 0.8 •  Isolation backend interface •  Full introspection •  Future •  Ambassador Pattern
17. Conclusion •  Wide global support with backend interfaces •  Service discovery improvement •  Road to multi host / orchestration
18. www.docker.io Thank you!