Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/2F3mH0r. Christy Norman Perez and Christopher Jones discuss creating multi-platform images using Docker; emulating architectures in containers, demonstrating pulling all of this together in a Docker Swarm consisting of workers of different CPU architectures such as arm64, ppc64le, s390x, and x86_64. Filmed at qconsf.com. Christy Norman Perez is a Software Developer at IBM who is focused on expanding and improving Docker's capabilities on IBM POWER Systems. Christopher Jones is a Software Developer at IBM, who works on development and testing of Docker on IBM POWER Systems. He can be found on Docker’s GitHub repository submitting and reviewing multi-architecture issues and pull requests.

1. The ARM to z of Multi-
Architecture Microservices
Chris Jones
Open Source Developer, IBM
Christy Norman Perez
Open Source Developer, IBM

2. InfoQ.com: News & Community Site
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minibooks
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Watch the video with slide
synchronization on InfoQ.com!
https://www.infoq.com/presentations/
microservices-multi-architecture

3. Purpose of QCon
- to empower software development by facilitating the spread of
knowledge and innovation
Strategy
- practitioner-driven conference designed for YOU: influencers of
change and innovation in your teams
- speakers and topics driving the evolution and innovation
- connecting and catalyzing the influencers and innovators
Highlights
- attended by more than 12,000 delegates since 2007
- held in 9 cities worldwide
Presented at QCon San Francisco
www.qconsf.com

4. • What is "multi-arch?"
• Challenges
• Benefits
• The path of multi-arch
Agenda
• Demo – Building images
• Demo – Shipping images
• Demo – Running Swarm
• Q&A

5. What are we talking about?

8. • User experience
across architectures
is the same
• Expand your project
Goals

9. Why should you care?

10. • Grow your project
• Strengths of other platforms
Benefits

11. Vendor lock-in

12. Benefits to others

14. Challenges

15. $ uname –m
ppc64le
$ docker run –it ubuntu
standard_init_linux.go:178: exec user process caused
“no such file or directory”
$ docker run –it ppc64le/ubuntu *
root@eb7051894530:/#
Usability

16. $ uname –m
arm64
$ docker run –it rethinkdb
standard_init_linux.go:178: exec user process caused
“no such file or directory”
$ docker run –it arm64/rethinkdb
docker: Error response from daemon: repository
arm64/rethinkdb not found: does not exist or no
pull access.
Availability

18. • Users have to remember they are on a different
architecture
• Arch-dependent (Devs?) image names harm usability
(ref frozen images script?)
• Siloed projects cause heartbreaks
Summary

19. Tools

20. • actual hardware
• cross-compiling
• full-system emulation (QEMU)
• user-mode emulation (binfmt_misc)
Building binaries and images

21. • Allows you to run ELF binaries that weren’t
compiled on your host architecture
• Maps non-native binaries to arch-specific
interpreters (e.g. QEMU)
• Pre-Configured in Docker for Mac!
binfmt_misc

22. binfmt_misc
qemu-arm qemu-ppc64le qemu-amd64
qemuX
binfmt_misc

23. $ uname -m
x86_64
# docker run ppc64le image
$ docker run -it --rm ppc64le/busybox:latest uname -m
ppc64le
Docker for Mac

24. # build ppc64le image on non-native hardware
$ docker build -v qemu-static-ppc64le -t awesome-app-
ppc64le -f Dockerfile.ppc64le .
Building using binfmt_misc
https://github.com/multiarch/qemu-user-static

25. Cross-compiling

26. # go
$ GOOS=linux GOARCH=arm go build
# java
$ javac HelloWorld.java
examples

27. Cross-Compile Workflow
java-app>
├── Dockerfile.build
├── Dockerfile.arm
├── Dockerfile.amd64
├── Dockerfile.ppc64le
├── Dockerfile.s390x
└── HelloWorld.java

28. Cross-Compile Workflow
# Dockerfile.build
FROM openjdk
COPY HelloWorld.java HelloWorld.java
RUN javac HelloWorld.java
Dev system (amd64):
$ docker build -t hwj -f Dockerfile.build . # repeatable build env
$ docker run --name hello-world-temp hwj # need container
$ docker cp hello-world-temp:HelloWorld.class . # copy out of container

29. Cross-Compile Workflow
Dev system (amd64):
$ docker build -t clnperez/hello-world-arm -f Dockerfile.arm .
$ docker push clnperez/hello-world-arm
# Dockerfile.arm
FROM arm32v7/openjdk
COPY HelloWorld.class HelloWorld.class
CMD ["java", "HelloWorld"]
ARM user:
$ docker run clnperez/hello-world-arm
Hello World!

30. Manifest lists

31. Manifest list
• A multi-arch "image” *
• Engine decides which to pull
• Extra image detail
• Use in place of image name
anywhere
myrepo/mylist
amd64 image arm image
ppc64le image
*but not

32. • Create & push manifest list to registry
• "Shallow pull" (inspect) of image
• Inspect manifest lists
`docker manifest` command

33. # create interactively using cli
$ docker manifest create ubuntu /
arm/ubuntu /
amd64/ubuntu /
ppc64le/ubuntu /
s390x/ubuntu
# push to registry
$ docker manifest push ubuntu
docker manifest

34. # or create using yaml
$ docker manifest push
-f clnperez_hw.yaml
docker manifest - yaml (soon)

35. $ docker manifest inspect ubuntu | grep “arch”
"architecture": "amd64",
"architecture": "arm",
"architecture": "arm64",
"architecture": "386",
"architecture": "ppc64le",
"architecture": "s390x",
docker manifest

36. Project structure

37. ├── Dockerfile.amd64
├── Dockerfile.arm
├── Dockerfile.ppc64le
├── Dockerfile.s390x
├── Dockerfile.windows
Makefiles, Dockerfiles & build scripts
• Multiple Dockerfiles (e.g.
Dockerfile.arm32v7)
• FROM can be passed in as
an ARG
• Can use manifest inspect to
get arch-specific FROM
• Be mindful of hardcoding
arch values

38. • If you must...
• ifdefs & build constraints
Optimizations
zfs.go:// +build linux freebsd solaris
zfs_unsupported.go:// +build !linux,!freebsd,!solaris

39. Putting it all together

40. tophj/qcon

41. tophj/qcon
• tophj/qcon:arm64
• tophj/qcon:amd64
• tophj/qcon:ppc64le
• tophj/qcon:s390x

42. ├── Dockerfile.armhf
├── Dockerfile.ppc64le
├── Dockerfile.s390x
├── Dockerfile.x86_64
├── img
│ ├── captain_logo.png
│ ├── captain.png
│ ├── christy_logo.png
│ ├── christy.png
│ ├── pink.png
│ └── tophj.png
└── server.go
docker swarm demo

43. # create our tophj/demo manifest list which points to our
# architecture specific images
$ docker manifest create tophj/demo tophj/x86_64-demo
tophj/armhf-demo tophj/ppc64le-demo tophj/s390x-demo
docker swarm demo

44. # annotate to change armhf to arm
$ docker manifest annotate tophj/demo tophj/armhf-demo
--os linux --arch arm
# finally push the manifest list
$ docker manifest push tophj/demo
docker swarm demo

45. $ docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER
STATUS
3nisms9qfi27ko0683bylxyud s390 Ready Active
7jwo7d5braat1l6n63j8xfue6 * x86_64 Ready Active Leader
n5tqx2yk77123sjiapqwmu14e armhf Ready Active
u30pwzlt5hthwbbsdok8nxyh8 ppc64le Ready Active
docker swarm demo

46. # start the swarm service using the multi-arch image name
$ docker service create --mode global --name dockercon -p 8082:8080 tophj/demo
# start a simple load-balancer for fun
$ docker run -itd -p 80:81 --name nginx -v /christy/nginx:/etc/nginx nginx
# visit the IP of your load balancer in your browser
# be sure to refresh for multi-arch fun
docker swarm demo

47. docker swarm demo

48. • Server image:
https://c1.staticflickr.com/4/3519/3462607995_150a6b2624_b.jpg
• HtcpcpTeapot image:
https://commons.wikimedia.org/wiki/File:Htcpcp_teapot.jpg
• Raspberry Pi is a trademark of the Raspberry Pi Foundation.
• https://github.com/dockersamples/docker-swarm-visualizer
• ARMHF VM from Scaleway
• X86 VM from DigitalOcean
• Gophers: http://gopherize.me
References & Legal

49. Thank You!
Go forth and multi-arch!
@qcon #qcon

50. Watch the video with slide
synchronization on InfoQ.com!
https://www.infoq.com/presentations/
microservices-multi-architecture