Dogestry: A Docker Registry Alternative

Slides for a talk at the Portland Docker Meetup on March 5, 2015.

Link to dogestry project: https://github.com/dogestry/dogestry.

Transcript

1. A Docker Registry Alternative ! Tom Offermann @toffermann March 5, 2015
2. Why So Popular?
3. One Reason…Docker Hub Docker provides image storage …for FREE!
4. ‣docker push ‣docker pull Easy to Get Started
5. ‣Operates on Layers Efficient
6. ‣Single Point of Failure ‣My code lives on their servers Downsides of 3rd Party Registry
7. ‣Old: docker/docker-registry ‣New: docker/distribution Run Own Registry
8. Dogestry
9. Dogestry…it’s a real project
10. ‣Command-line tool, written in Go ‣Store docker images in S3 bucket ‣Upload and download docker images What is Dogestry?
11. Docker Remote API $ curl http://192.168.33.10:2375/version! ! {! "ApiVersion": "1.16",! "Arch": "amd64",! "GitCommit": "4595d4f",! "GoVersion": "go1.3.3",! "KernelVersion": "3.13.0-35-generic",! "Os": "linux",! "Version": "1.4.0"! }!
12. Docker CLI $ docker version! ! Client version: 1.3.2! Client API version: 1.15! Go version (client): go1.3.3! Git commit (client): 39fa2fa! OS/Arch (client): darwin/amd64! Server version: 1.4.0! Server API version: 1.16! Go version (server): go1.3.3! Git commit (server): 4595d4f!
13. GET Docker Image REQUEST ! GET /images/busybox/get! ! RESPONSE ! HTTP/1.1 200 OK! Content-Type: application/x-tar! Date: Sun, 01 Mar 2015 04:43:14 GMT! Transfer-Encoding: chunked! ! Binary Data Stream!
14. LOAD Docker Image REQUEST ! POST /images/load! ! Tarball in body! ! RESPONSE ! HTTP/1.1 200 OK! Date: Sun, 01 Mar 2015 04:50:52 GMT! Content-Length: 0! Content-Type: text/plain; charset=utf-8!
15. “Simple” Replacement: PUSH docker push 1. GET /images/busybox/get 2. Save tarball to S3
16. 1. Get tarball from S3 2. POST /images/load “Simple” Replacement: PULL docker pull
17. Simple ≠ Efficient
18. It’s All About Layers
19. Image Layers $ docker history busybox! IMAGE CREATED CREATED BY ! 4986bf8c1536 8 weeks ago ... CMD [/bin/sh] ! ea13149945cb 8 weeks ago ... ADD file:8cf517d90fe79547c4! df7546f9f060 5 months ago ... MAINTAINER Jérôme Petazzo ! 511136ea3c5a 20 months ago
20. Docker Image Tarball busybox! !"" 4986bf8c15363...! # !"" VERSION! # !"" json! # $"" layer.tar! !"" 511136ea3c5a6...! # !"" VERSION! # !"" json! # $"" layer.tar! # ...! $"" repositories
21. Layer JSON ## busybox/4986bf8c1536.../json! ! {! "id": “4986bf8c15363...”,! "parent": “ea13149945cb...”,! "created": "2014-12-31T22:23:56.943403668Z",! "container": “83dcf36ad104...”,! …! }
22. repositories JSON {! "busybox": {! "foo": “4986bf8c1536...",! "latest": "4986bf8c1536..."! }! }
23. Walk Image History IMAGE:TAG TOP LAYER ID! busybox:latest => 4986bf8c1536! ! LAYER ID! ! ! PARENT ID! 4986bf8c1536 => ea13149945cb! ea13149945cb => df7546f9f060! df7546f9f060 => 511136ea3c5a! 511136ea3c5a => None
24. Save Image Layers in S3 images/4986bf8c1536.../layer.tar! images/4986bf8c1536.../VERSION! images/4986bf8c1536.../json! ! images/511136ea3c5a.../layer.tar! images/511136ea3c5a.../VERSION! images/511136ea3c5a.../json
25. Save Repository Metadata in S3 KEY VALUE! repositories/busybox/latest 4986bf8c15...! repositories/busybox/foo 4986bf8c15...! repositories/busybox/bar 4986bf8c15...
26. ‣Identify layers missing from S3 ‣Export docker image ‣Write missing layers to /tmp ‣Upload layers to S3 Dogestry PUSH
27. ‣Identify layers missing from docker host ‣Download missing layers from S3 ‣Package layers as docker image tarball ‣Load tarball into docker host Dogestry PULL
28. DEMO
29. Contributions Welcome http://github.com/dogestry/dogestry
30. Thank You! ! Tom Offermann @toffermann March 5, 2015