Presented from gdg devfair 2014 and gdg korea golang seoul meetup 2015. Added explanation about go 1.4 official android support a little from gdg korea golang seoul meetup presentation.

1. (Live) Build and run
Golang Web server on
Android.avi
SeongJae Park <sj38.park@gmail.com>

2. Nice To Meet You
SeongJae Park
sj38.park@gmail.com
golang newbie programmer

3. Disclaimer
The main part of session is live-coding. This
slide has only little information.
Inspired by camlistore and outyet
Maybe useless, *just for fun*

4. Goal Of This Session
Build and run Golang web server on Android
Live Coding

5. golang: Programming Language
for simple, reliable, and efficient software.
http://blog.golang.org/5years/gophers5th.jpg

6. Web server
Processes request via HTTP protocol
Web Server Client

7. Web server
Processes request via HTTP protocol
Listen a socket
Receive HTTP request from the socket
Web Server Client
url: /blahblah,
method: GET

8. Web server
Processes request via HTTP protocol
Listen a socket
Receive HTTP request from the socket
Process the request
Web Server Client
url: /blahblah,
method: GET

9. Web server
Processes request via HTTP protocol
Listen a socket
Receive HTTP request from the socket
Process the request
Send HTTP response to client using the socket
Web Server Client
url: /blahblah,
method: GET
Status: OK,
Body: <p>welcome</p>

10. (Live) Simple Golang Webserver
…...

11. (Live) Simple Golang Webserver
…... complete
net/http rules
The code: https://github.
com/sjp38/linuxOutYet/tree/804aa370f5adbf3d
4377ee1b1e862cbc49d81c1c

12. Golang and Android
● Golang Supports Android officially from v1.4
○ The support focus on Application; just let .so or .apk
https://blog.golang.org/gopher/gopher.png
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Android_robot.svg/511px-Android_robot.svg.png

13. Golang and Android
● Golang Supports Android officially from v1.4
○ The support focus on Application; just let .so or .apk
○ Requires complex build process and client code
https://blog.golang.org/gopher/gopher.png
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Android_robot.svg/511px-Android_robot.svg.png

14. Golang and Android
● Golang Supports Android officially from v1.4
○ The support focus on Application; just let .so or .apk
○ Requires complex build process and client code
○ Couldn’t be more simple, easier?
https://blog.golang.org/gopher/gopher.png
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Android_robot.svg/511px-Android_robot.svg.png

15. Golang on Android: Background
Android is a variant of Linux system with ARM
x86 Android exist, though...
http://www.kitguru.net/wp-content/uploads/2012/03/linux-android.png

16. Golang on Android: Background
Android is a variant of Linux system with ARM
x86 Android exist, though...
Go supports ARM & Linux Officially
with static-linking
http://www.kitguru.net/wp-content/uploads/2012/03/linux-android.png

17. Golang on Android: Background
Android is a variant of Linux system with ARM
x86 Android exist, though...
Go supports ARM & Linux Officially
with static-linking
So, why not?
http://www.kitguru.net/wp-content/uploads/2012/03/linux-android.png

18. Golang on Android: Plan
1. Cross compile Go program as ARM / Linux

19. Golang on Android: Plan
1. Cross compile Go program as ARM / Linux
2. Include the binary in assets/ of Android app

20. Golang on Android: Plan
1. Cross compile Go program as ARM / Linux
2. Include the binary in assets/ of Android app
3. Copy the binary in private space of the app

21. Golang on Android: Plan
1. Cross compile Go program as ARM / Linux
2. Include the binary in assets/ of Android app
3. Copy the binary in private space of the app
4. Give execute permission to the binary
/data/data/com.example.goRunner/files # ls -al
-rwxrwxrwx u0_a55 u0_a55 4512840 2014-11-28 17:45 gobin

22. Golang on Android: Plan
1. Cross compile Go program as ARM / Linux
2. Include the binary in assets/ of Android app
3. Copy the binary in private space of the app
4. Give execute permission to the binary
5. Execute it
/data/data/com.example.goRunner/files # ls -al
-rwxrwxrwx u0_a55 u0_a55 4512840 2014-11-28 17:45 gobin

23. (Live) Golang on Android
……

24. (Live) Golang on Android: Problem
…… Not successful
go binary runner code:
https://github.
com/sjp38/goOnAndroidFA/releases/tag/devfair
2014.gdg.kr

25. (Live) Golang on Android: Problem
…… Not successful
It has no /etc/hosts
CA Certs path is different with pure Linux
/system/etc/security/cacerts

26. (Live) Golang on Android: Problem
…… Not successful
It has no /etc/hosts
CA Certs path is different with pure Linux
/system/etc/security/cacerts
Android is a variant of, not pure Linux
GOOS=android has same problem, too :’(

27. (Live) Golang on Android: Solution
It has no /etc/hosts
Get IP manually
Certifications path is different
Use those certifications

28. (Live) Golang on Android: Again
……

29. (Live) Golang on Android
…… Complete
It’s hacky, but works
The code: https://github.
com/sjp38/linuxOutYet/releases/tag/devfair201
4.gdg.kr

30. Summary
Golang program can run on Android

31. Summary
Golang program can run on Android
Officially as .so or .apk file

32. Summary
Golang program can run on Android
Officially as .so or .apk file
Or, as elf binary with unofficial, little hack

33. Summary
Golang program can run on Android
Officially as .so or .apk file
Or, as elf binary with unofficial, little hack
Some features don’t work on Android, yet
Still need some hacks

34. Final Source Code
go web server: https://github.
com/sjp38/linuxOutYet/releases/tag/devfair201
4.gdg.kr
go program runner(Android app): https://github.
com/sjp38/goOnAndroidFA/releases/tag/devfair
2014.gdg.kr

35. This slide has been used for
GDG Korea DevFair 2014
GDG Korea Golang Seoul Meetup

36. This work by SeongJae Park is licensed under the
Creative Commons Attribution-ShareAlike 3.0 Unported
License. To view a copy of this license, visit http:
//creativecommons.org/licenses/by-sa/3.0/.