Snappy (Ubuntu-Core) On Pi2. Time + Docker

[ghostseven]

I ran up Snappy on the Pi2 yesterday and found a few interesting things. And wanted to ask for some help and advice.

1. The Snappy tool will not install anything or version check without the time being set correctly ( it gives criptic errors) a quick sudo date -s "Tue 3 Feb 22:22 UTC 2015" solves this.

2. There appears to be no docker package on the version of snappy for Pi2, either that or something odd is going on.

3. Snappy documentation on the web is very much in its infancy

Now some questions.

1. Does anyone know how to setup NTP time on snappy, this is really very important to use this platform in any meaningful way.

2. Does anyone know why the docker package is not available and how to resolve this?

3. Other than the stock ubuntu snappy pages can anyone point me to a good source of basic snappy guides or things to look out for, I am not new to linux but I appreciate there are a lot of subtle differences with snappy to stock ubuntu.

Thanks!

[philipz]

I also have the same questions.
How to use snappy ? Dose have any document or guide about it ? http://developer.ubuntu.com/en/snappy/
I didn't find out docker package, how to install docker?

[fuxi]

Could lack of Docker be caused by ARM processor. Docker does not support it yet.

[ghostseven]

Could lack of Docker be caused by ARM processor. Docker does not support it yet.

Dam I was not aware of that, this will be the problem for sure! I really should have checked that, thank you!

[fuxi]

I wonder how much work would it take to actually add ARM support to code of Docker.
There is already some of work done (from my understanding): https://github.com/stevef1uk/docker_for_rpi

[ghostseven]

Yea just seen this myself,

Looks like there are some more ports as well

https://github.com/resin-io/lxc-docker- ... D/releases

It also appears that it will run on Debian Jessie

http://eva-quirinius.blogspot.co.uk/201 ... essie.html

[fuxi]

This Docker issue looks relevant: https://github.com/docker/docker/issues/636

[dieter]

sorry this answer is not related to Snappy,

but if you'd like to use Docker on your Raspberry Pi 2 instantly without all these manual tasks of compiling Go and Docker and tweak your Linux kernel to get it ready for advanced Docker features, we've build a ready-to-run Raspbian Image with 3.18.6 kernel and Docker v1.4.1 pre-installed. And it uses OverlayFS with Docker.

Just get it here: http://blog.hypriot.com/kick-ass-raspbe ... -1-dot-4-1

[RV06]

If you compile Docker on ARM you won't have all the features of Docker, and you may even be a problem to x64 docker users.

The point is about the Docker registry:
It is a central repository of Docker images. Everyone can pull public images from there, and push its own images and make them public.
Today, this repository does not make any difference between target architectures.
And a x64 image could never run on a Pi, nor a ARM image could run on a x64 PC.

I guess that is the main reason why they don't yet put any efforts on compiling Docker for ARM architecture.

[philipz]

Dear All,

I have run Raspbian by Docker on X86 PC environment.

sudo apt-get install qemu-user-static
sudo docker run -it --rm -v /usr/bin/qemu-arm-static:/usr/bin/qemu-arm-static philipz/rpi-raspbian bash

https://www.facebook.com/photo.php?fbid ... =1&theater

[dcarley]

You can enable NTP through systemd:

Code: Select all

timedatectl set-ntp true

This should be the default in future: https://lists.ubuntu.com/archives/snapp ... 00231.html

[beagile]

Hi ghostseven,

while I cannot help you with Docker on Ubuntu Snappy I just wanted to share some interesting facts with you regarding Docker and ARM. The lack of Docker is not caused by the fact that Docker does not run on ARM. To the contrary Docker runs very well on ARM.

We just created a very simple to use SD card image based on Raspbian to prove it. It combines the latest 3.18.8 kernel with the lastes Docker 1.5.0 version. Just flash it to your SD card and your are up and running in no time.

You can find our image and information about how to use it here: http://blog.hypriot.com/heavily-armed-a ... -1-dot-5-0

Govinda
- blog.hypriot.com -

[mattrix]

The point is about the Docker registry:
It is a central repository of Docker images. Everyone can pull public images from there, and push its own images and make them public.
Today, this repository does not make any difference between target architectures.
And a x64 image could never run on a Pi, nor a ARM image could run on a x64 PC.

Not true.
There are heaps of ARM images available on the registry.
eg: https://hub.docker.com/u/mazzolino/
https://registry.hub.docker.com/u/resin/rpi-raspbian/
It is also very easy to create your own base images and add it to the registry.

[9NmWy]

docker 1.6 appeared in the snappy store.
I installed it but can't run docker it said me

(RaspberryPi2)ubuntu@localhost:~$ docker
mkdir: cannot create directory ‘/tmp/snaps/docker’: Permission denied

(RaspberryPi2)ubuntu@localhost:~$ sudo docker
sudo: docker: command not found

So I have been confused and tried to understand what happened.

(RaspberryPi2)ubuntu@localhost:~$ snappy info
release: ubuntu-core/devel
architecture: armhf
frameworks: docker, webdm
apps:


(RaspberryPi2)ubuntu@localhost:~$ snappy list -v
Name Date Version Developer
ubuntu-core* 2015-04-11 4
ubuntu-core 2015-04-11 4
docker* 2015-05-17 1.6.1.002
webdm* 2015-05-17 0.6.1
pi2* 2015-04-16 0.11 lool


(RaspberryPi2)ubuntu@localhost:~$ ps ax | grep docker
6800 ? Ss 0:00 /bin/bash /apps/docker/1.6.1.002/bin/docker.start
6806 ? Sl 0:00 docker.armhf -d -G docker -g /var/lib/apps/docker/1.6.1.002 -H unix:///var/run/docker.sock
6928 pts/1 R+ 0:00 grep --color=auto docker

It seemed to me docker installed and its daemon ran.
But why I couldn't run docker client?

[riklaunim]

I wonder what's the point in running Docker on ARM board. RPiv2 has it hardware limits like RAM that easily can be consumed by few working docker containers. Not to mention that /var/lib/docker will prefer bigger microSD cards

[pdenhaan]

I wonder what's the point in running Docker on ARM board. RPiv2 has it hardware limits like RAM that easily can be consumed by few working docker containers. Not to mention that /var/lib/docker will prefer bigger microSD cards

Running containers for: rsyncd, nginx, dockergen (to automatically configure nginx as a reverse proxy for the web containers), mariadb, two wordpress/php/apache containers, and ghost. Plus four data containers makes 11. Memory usage is about 48%. You seem to underestimate just how lightweight Docker containers are; they are not VMs!

Obviously all of the above are descendants of the same (archlinux) base image. /var/lib/docker lives on an external mSATA SSD, as does 1GB of swap with swappiness tuned all the way down.

[se7enack]

Check out this step-by_step:
http://www.dorkcloud.com/blog/index.php ... pberry-Pi2