I have found Eclipse Kura snap as “kura-nn” on snapcraft store. But it unable to find using snap find option. Is it because of unset license? Where can I find the kura snap? As the Kura documentation shows that it support Ubuntu core. Please find the doc link below.
https://iot.eclipse.org/gateways/
I am trying to install Eclipse Kura on Ubuntu core running of Raspberry Pi.
Your help will be appreciated.
Can someone help me.
Thanks & Regards,
Ashish
It looks like it’s only build for amd64 (Intel/AMD 64-bit CPU:s), Raspberry Pi uses an arm CPU.
https://snapcraft.io/kura-nn (see: all versions, inspect the Architecture drop down). For reference, see https://snapcraft.io/nextcloud with is built for 2 arm variants.
Thanks, will try to create one for arm CPU.
better contact the owner of the snap so he just enables the arm architecture for the existing one ) or help him to do that in case there are changes/fixes needed) 
as it seems this snap is owned by @ondra
Hi @ajoshi2402
sorry for late reply, it was still some work in progress.
However I now released kura-nn for armhf and arm64 (I have not tested arm64 version yet)
Feel free to give it spin. If you want to use bluetooth, you should also install bluez snap and connect all interfaces.
I have not build 3.3 snapshot for other than amd64 architectures, but that should come soon as well.
Kura with network control is still something I’m working on when time allows, so for now only no-network version is available as snap
@ajoshi2402 kura and kura-nn is now available for amd64, armhf and arm64 architectures
feedback welcomed
Unfortunately I am unable to get your kura-nn snap executing on RPI3 let me know if I can provide more info. Thanks for your awesome contributions for RPI, look forward to this working
kura-nn daemon aborting at startup on Raspberry pi 3, throwing following
snap logs kura-nn
....
Problematic frame:
# C [libudev.so.1+0x65e4] udev_monitor_filter_update+0x13
.....
Info from error logs
sudo cat /tmp/snap.0_kura-nn_N45udK/tmp/hs_err_pid1197.log | more
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x51f2e5e4, pid=1197, tid=0x5183e470
#
# JRE version: OpenJDK Runtime Environment (8.0_172) (build 1.8.0_172-106)
# Java VM: OpenJDK Client VM (25.172-b106 mixed mode, Evaluation linux-aarch32 )
# Problematic frame:
# C [libudev.so.1+0x65e4] udev_monitor_filter_update+0x13
………………
………….
..
--------------- T H R E A D ---------------
Current thread (0x01b8b800): JavaThread "LinuxUdevNative" daemon [_thread_in_native, id=1380, stack(0x517ef000,0x5183f000)]
udev.so.1+0x65e4] udev_monitor_filter_update+0x13
3
……
…..
History
Clean install of Ubuntu Core for Raspberry Pi 3, initial installed kura-nn (Stable) 3.2 with above error thrown. Then
snap switch --edge kura-nn 3.3.0-SNAPSHOT-110-g56cd264 , same error happening
snap list
xxxxxx@localhost:~$ snap list
Name Version Rev Tracking Publisher Notes
bluez 5.47-3 167 stable canonical -
core 16-2.34.2+git872.88ec69f 5112 edge canonical core
kura-nn 3.3.0-SNAPSHOT-110-g56cd264 26 edge ondra -
pi2-kernel 4.4.0-1092.100 56 edge canonical kernel
pi3 16.04-0.5 22 edge canonical gadget
XXXXX@localhost:~$ snap info kura-nn
name: kura-nn
summary: Eclipse Kura™ An OSGi-based Application Framework for M2M Service Gateways
publisher: ondra
license: unset
description: |
............
............
commands:
- kura-nn.help
- kura-nn.kura-debug
services:
kura-nn.kura: simple, enabled, inactive
snap-id: DeRkWuxe3GADn0kULmru9wMwsFBsquJM
tracking: edge
refresh-date: yesterday at 22:36 UTC
channels:
stable: 3.2.0 (20) 167MB -
candidate: 3.2.0 (20) 167MB -
beta: 3.2.0 (20) 167MB -
edge: 3.3.0-SNAPSHOT-110-g56cd264 (26) 161MB -
installed: 3.3.0-SNAPSHOT-110-g56cd264 (26) 161MB -
list of changes
snap changes
ID Status Spawn Ready Summary
1 Done yesterday at 07:15 UTC yesterday at 07:15 UTC Initialize system state
2 Done yesterday at 07:15 UTC yesterday at 07:16 UTC Initialize device
4 Done yesterday at 09:42 UTC yesterday at 09:42 UTC Install "upower" snap
5 Done yesterday at 09:45 UTC yesterday at 09:45 UTC Remove "upower" snap
6 Done yesterday at 09:58 UTC yesterday at 09:58 UTC Refresh all snaps: no updates
7 Done yesterday at 10:20 UTC yesterday at 10:24 UTC Install "kura-nn" snap
8 Done yesterday at 10:58 UTC yesterday at 10:58 UTC Running service command
9 Done yesterday at 11:03 UTC yesterday at 11:04 UTC Install "bluez" snap
10 Done yesterday at 11:05 UTC yesterday at 11:05 UTC Running service command
11 Done yesterday at 11:06 UTC yesterday at 11:06 UTC Running service command
12 Done yesterday at 11:08 UTC yesterday at 11:08 UTC Running service command
13 Done yesterday at 11:10 UTC yesterday at 11:10 UTC Running service command
14 Done yesterday at 22:33 UTC yesterday at 22:33 UTC Switch "kura-nn" snap to edge
15 Done yesterday at 22:34 UTC yesterday at 22:36 UTC Refresh "kura-nn" snap
16 Done yesterday at 22:36 UTC yesterday at 22:36 UTC Switch "kura-nn" snap to edge
snap interfaces
snap interfaces
Slot Plug
bluez:service bluez:client
:account-control -
:alsa -
:autopilot-introspection -
:bluetooth-control -
:broadcom-asic-control -
:browser-support -
:camera -
:can-bus -
:classic-support -
:core-support -
:daemon-notify -
:dcdbas-control -
:docker-support -
:dvb -
:firewall-control -
:framebuffer -
:fuse-support -
:gpg-keys -
:gpg-public-keys -
:gpio-memory-control -
:greengrass-support -
:hardware-observe -
:hardware-random-control -
:hardware-random-observe -
:home -
:hostname-control -
:io-ports-control -
:joystick -
:kernel-module-control -
:kubernetes-support -
:kvm -
:log-observe -
:lxd-support -
:mount-observe -
:netlink-audit -
:netlink-connector -
:network kura-nn
:network-bind kura-nn
:network-control -
:network-observe -
:network-setup-control -
:network-setup-observe -
:opengl -
:openvswitch-support -
:physical-memory-control -
:physical-memory-observe -
:ppp -
:process-control -
:raw-usb -
:removable-media -
:shutdown -
:snapd-control -
:ssh-keys -
:ssh-public-keys -
:system-observe -
:system-trace -
:time-control -
:timeserver-control -
:timezone-control -
:tpm -
:uhid bluez
pi3:bcm-gpio-0 -
pi3:bcm-gpio-1 -
pi3:bcm-gpio-10 -
pi3:bcm-gpio-11 -
pi3:bcm-gpio-12 -
pi3:bcm-gpio-13 -
pi3:bcm-gpio-14 -
pi3:bcm-gpio-15 -
pi3:bcm-gpio-16 -
pi3:bcm-gpio-17 -
pi3:bcm-gpio-18 -
pi3:bcm-gpio-19 -
pi3:bcm-gpio-2 -
pi3:bcm-gpio-20 -
pi3:bcm-gpio-21 -
pi3:bcm-gpio-22 -
pi3:bcm-gpio-23 -
pi3:bcm-gpio-24 -
pi3:bcm-gpio-25 -
pi3:bcm-gpio-26 -
pi3:bcm-gpio-27 -
pi3:bcm-gpio-3 -
pi3:bcm-gpio-4 -
pi3:bcm-gpio-5 -
pi3:bcm-gpio-6 -
pi3:bcm-gpio-7 -
pi3:bcm-gpio-8 -
pi3:bcm-gpio-9 -
pi3:bt-serial -
pi3:i2c-0 -
pi3:i2c-1 -
pi3:i2c-2 -
- bluez:bluetooth-control
- bluez:home
- bluez:network-control
- kura-nn:bluetooth-control
- kura-nn:bluez
- kura-nn:firewall-control
- kura-nn:hardware-observe
- kura-nn:home
- kura-nn:io-ports-control
- kura-nn:log-observe
- kura-nn:mount-observe
- kura-nn:netlink-audit
- kura-nn:network-control
- kura-nn:network-setup-control
- kura-nn:ppp
- kura-nn:process-control
- kura-nn:removable-media
- kura-nn:system-observe
- kura-nn:time-control
Did you try to connect all these unconnected interfaces (one of system-observe and/or hardware-observe might be the ones allowing udev_monitor access …)
@auphof indeed as @ogra pointed out , you need to connect all those interfaces first, otherwise apparmor will flag any attempt of kura to access hw or bind network
There is helper script which does this all for you:
$ /snap/kura-nn/current/connect-interfaces
Once interfaces are connected, restart kura service:
$ sudo systemctl restart snap.kura-nn.*
You also might want to install bluez snap if you want to use bluetooth…
Thank you @ondra and @ogra, kura daemon is now running after /snap/kura-nn/current/connect-interfaces and I can continue my exploring.
I am just beginning to explore using ubuntu-core and snap’s. Is there a readme or other document such useful initialization can be recorded.
cat /snap/kura-nn/current/readme.txt seems to be generic and I can’t locate a readme on Github kura-snap
you are welcome @auphof yeah that read me is pulled from kura, non snap related
Usually generic snap package info applies on all snaps you get from store, classic snaps are a bit special, but on Ubuntu Core you get only strict confined snaps anyway. kura is strictly confined snap, which means by default kura’s sandbox is very restricted and you need to grant it appropriate permissions for it to function. So rule of thumb for any snap install is:
$ snap connect <snap nane>:<interface name> core:<interface name>
Some snaps can be deemed as trusted and then step 3 is done automatically, in which case you just install snap and off you go…
Eventually this would be long term goal when kura snap matures.
You managed to catch kura snap very fresh so feel free to feedback when things are not working 
As for snaps created by me, I usually try to add help function, typically $ <snap name>.help
which gives you info about configuration options, but it’s not always the case if there is nothing to be configured
as for kura(-nn) snap, this is not added yet, I plan to add there things like java memory configuration as kura can run on pi3 as well as on 8G RAM gateway…