Use `docker buildx` to add arm platform to our docker image

Now docker can Building Multi-Architecture Docker Images With Buildx which is very nice.

We use a different branch/tag for armhf support in the past, I believe it's time to use the latest docker buildx technology now.

Related to: #52 #9

We have just published an experimental version of SMF 1.2:

$ docker buildx imagetools inspect zixia/simple-mail-forwarder:1.2
Name:      docker.io/zixia/simple-mail-forwarder:1.2
MediaType: application/vnd.docker.distribution.manifest.list.v2+json
Digest:    sha256:7cacf28ae8a6d86c6dab3d42dc5dd0464235f7cd8de524bb12c53aec11129398
           
Manifests: 
  Name:      docker.io/zixia/simple-mail-forwarder:1.2@sha256:b68f59095e5c38bd22677885e9c78e2bb9c4e9e810059aadde6ab650cc3d204a
  MediaType: application/vnd.docker.distribution.manifest.v2+json
  Platform:  linux/amd64
             
  Name:      docker.io/zixia/simple-mail-forwarder:1.2@sha256:45de2c7c96ebba77ed708e221cdb79e03ac18f8c20e94a9c75af80e49a28748c
  MediaType: application/vnd.docker.distribution.manifest.v2+json
  Platform:  linux/arm/v6
             
  Name:      docker.io/zixia/simple-mail-forwarder:1.2@sha256:e22830cca614c2631e698261dcfd182b3a66bc4fd0d78881b1c9896ae623c80e
  MediaType: application/vnd.docker.distribution.manifest.v2+json
  Platform:  linux/arm/v7

Please let me know if you can confirm any of those versions works as expected.

Implemented by cd1410d

We have republished v1.3 with multi-platforms docker image support (powered by buildx), please test and let me know whether it works under your platform.

Hi @dimitrovs, please take a look at our new v1.3 version of multi-platforms docker images which can manage all architectures (arm/x86) in the same master branch!

maybe im doing something wrong but -

the container restarts after that, stuck on a loop (arm64, rock pi 4A)

@mrsufgi It seems that the arch is not right for your platform:

cannot execute binary file: Exec format error

Could you please tell us what docker image platform are you using?

We will use the arm version from https://github.com/just-containers/s6-overlay/releases/, please let me know if you can confirm it can work with the arm64 with rock pi 4A or not:

docker-simple-mail-forwarder/script/install-s6-overlay.sh

Lines 13 to 21 in 044933a

    
           armv6l) 
        
             # fall through 
        
             ;& 
        
           armv7l) 
        
             ARCH=armhf 
        
             ;; 
        
           aarch64 | armv8l) 
        
             ARCH=arm 
        
             ;;

Update

According to this SO answer: Differences between arm64 and aarch64

So AArch64 and ARM64 refer to the same thing.

Maybe we need to use the aarch64 version of s6-overlay for aarch64 and armv8l?

The latest SMF with v1.3.1 has been published.

Please try to upgrade to it to see if your problem has been solved or not on the arm64 rock pi 4A.

docker image is still 1.3 (and latest is still 1.3), just removed local image and started again, same error.

Linux rockpi-4a 5.8.12-rockchip64 #20.08.5 SMP PREEMPT Sun Sep 27 12:47:16 CEST 2020 aarch64 GNU/Linux

@huan I deleted my existing images and pulled again (1.3, 1.3.1 wasn't available).
I will try again, but that didn't seem to work :O

Just tried latest and 1.3 tag. They seem not to work. The container boot-loops.
If I run it from entrypoint: /bin/sh then run the entrypoint manually I get:

s6-supervise syslog-ng: warning: can't happen: timeout while the service is up!
s6-supervise postfix: warning: can't happen: timeout while the service is up!

And it keeps going on like that.

Raspsberry Pi OS with armf userspace and 64bit kernel.

We have created a new issue to track the arm 64 architecture and let's close this finished issue.

	armv6l)
	# fall through
	;&
	armv7l)
	ARCH=armhf
	;;
	aarch64 \| armv8l)
	ARCH=arm
	;;