Failure to build and run GGC in Docker on Ubuntu Core

Question

I have Ubuntu Core 18 (GNU/Linux 5.3.0-1033-raspi2 armv7l) installed on a Raspberry Pi 4 Model B. As the aws-iot-greengrass snap has limited functionality, I decided to explore the possibility of installing GGC in a Docker container. I installed the Docker snap (v19.03.11), and attempted to install the amazon/ws-iot-greengrass docker image from docker hub (  ). After putting the GGC certs on the system, my first attempt at running the image failed with the following error:  
**FATAL tini (6) exec /greengrass-entrypoint.sh failed: Exec format error**  
  
As I appeared to have the same issue described in (  ), I removed the previous GG image and built my own Docker image using the Dockerfile download from     
  
I followed the instructions in the README, using the 'Dockerfile.alpine-armv7l' dockerfile. The build appeared to be successful, as the Dockerfile appeared to execute without issues, aside from two warnings:  
**WARNING: Ignoring APKINDEX.00740ba1.tar.gz: No such file or directory**  
**WARNING: Ignoring APKINDEX.d8b2a6f4.tar.gz: No such file or directory**  
The image can be revealed with **docker image ls** as arm7l/aws-greengrass:1.10.2.  
  
However, when I try to run the image I receive the error:  
**FATAL tini (6) exec /greengrass-entrypoint.sh failed: Permission denied**  
  
I would appreciate any help in figuring out why this error occurs and whether my use scenario is even possible. I understand it's not conventional.  
  
Edited by: ole-OG on Sep 14, 2020 9:06 PM

Answer

I understand that greengrass-entrypoint.sh is copied from the folder containing Dockerfiles during the image build process, but I am unable to locate location of greengrass-entrypoint.sh. It may differ from standard Linux systems due to the Ubuntu Core directory system, and the fact that Docker is installed as a snap. Any ideas?

Answer

I removed the previously build image, changed the permissions of greengrass-entrypoint.sh in the directory containing Dockerfiles to grant rwx permission to all, then rebuilt the image. This appears to have worked, as confirmed by the successful deployment of a Greengrass group with stream manager enabled and a Python 3.7 Lambda function (HelloWorldTrigger from the greengrasssdk).

Answer

Can you tell me the file permission of greengrass-entrypoint.sh in your system? Is the executable bit enabled?

Answer

The output of **sudo mount** is:  
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)  
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)  
udev on /dev type devtmpfs (rw,nosuid,relatime,size=1883688k,nr_inodes=158485,mode=755)  
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)  
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=391432k,mode=755)  
/dev/mmcblk0p2 on /writable type ext4 (rw,relatime)  
/writable/system-data/var/lib/snapd/seed/snaps/core18_1889.snap on / type squashfs (ro,relatime)  
/writable/system-data/var/lib/snapd/snaps/pi-kernel_200.snap on /lib/modules type squashfs (ro,relatime)  
/writable/system-data/var/lib/snapd/snaps/pi-kernel_200.snap on /lib/firmware type squashfs (ro,relatime)  
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,mode=755)  
tmpfs on /etc/fstab type tmpfs (rw,nosuid,noexec,relatime,mode=755)  
/dev/mmcblk0p2 on /etc/writable type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/apparmor.d/cache type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/dbus-1/session.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/dbus-1/system.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/hosts type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/iproute2 type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/modprobe.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/modules-load.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/netplan type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/network/if-up.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/ssh type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/sudoers.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/systemd type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/udev/rules.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/cloud type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/sysctl.d type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/default/swapfile type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/environment type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/systemd/system type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /etc/machine-id type ext4 (rw,relatime)  
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)  
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)  
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)  
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)  
cgroup on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)  
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)  
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)  
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)  
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)  
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)  
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)  
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)  
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)  
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)  
cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma)  
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)  
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=27,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=32865)  
debugfs on /sys/kernel/debug type debugfs (rw,relatime)  
mqueue on /dev/mqueue type mqueue (rw,relatime)  
configfs on /sys/kernel/config type configfs (rw,relatime)  
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/dbus type ext4 (rw,relatime)  
tmpfs on /media type tmpfs (rw,relatime)  
/dev/mmcblk0p2 on /var/snap type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/misc type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/log type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/private/systemd type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/snapd type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /home type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/systemd type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /snap type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/cloud type ext4 (rw,relatime)  
tmpfs on /var/lib/sudo type tmpfs (rw,relatime,mode=700)  
tmpfs on /mnt type tmpfs (rw,relatime)  
/dev/mmcblk0p2 on /root type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/extrausers type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/tmp type ext4 (rw,relatime)  
tmpfs on /tmp type tmpfs (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/console-conf type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/cache type ext4 (rw,relatime)  
/dev/mmcblk0p2 on /var/lib/dhcp type ext4 (rw,relatime)  
/writable/system-data/var/lib/snapd/seed/snaps/core18_1889.snap on /snap/core18/1889 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/writable/system-data/var/lib/snapd/seed/snaps/core18_1889.snap on /writable/system-data/snap/core18/1889 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/snapd_8792.snap on /snap/snapd/8792 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/snaps/snapd_8792.snap on /writable/system-data/snap/snapd/8792 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/pi_73.snap on /snap/pi/73 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/snaps/pi_73.snap on /writable/system-data/snap/pi/73 type squashfs (ro,nodev,relatime)  
/writable/system-data/var/lib/snapd/snaps/pi-kernel_200.snap on /snap/pi-kernel/200 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/writable/system-data/var/lib/snapd/snaps/pi-kernel_200.snap on /writable/system-data/snap/pi-kernel/200 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/aws-iot-greengrass_6.snap on /snap/aws-iot-greengrass/6 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/snaps/aws-iot-greengrass_6.snap on /writable/system-data/snap/aws-iot-greengrass/6 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/core_9805.snap on /snap/core/9805 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/snaps/core_9805.snap on /writable/system-data/snap/core/9805 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/nano_29.snap on /snap/nano/29 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/snaps/nano_29.snap on /writable/system-data/snap/nano/29 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/seed/snaps/pi-kernel_186.snap on /snap/pi-kernel/186 type squashfs (ro,nodev,relatime,x-gdu.hide)  
/var/lib/snapd/seed/snaps/pi-kernel_186.snap on /writable/system-data/snap/pi-kernel/186 type squashfs (ro,nodev,relatime)  
/var/lib/snapd/snaps/snapd_8792.snap on /usr/lib/snapd type squashfs (ro,nodev,relatime)  
/dev/mmcblk0p1 on /boot/uboot type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)  
tmpfs on /run/snapd/ns type tmpfs (rw,nosuid,noexec,relatime,size=391432k,mode=755)  
nsfs on /run/snapd/ns/aws-iot-greengrass.mnt type nsfs (rw)  
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=391428k,mode=700,uid=1000,gid=1000)  
  
The output of **cat /etc/os-release** is:  
cat /etc/os-release  
NAME="Ubuntu Core"  
VERSION="18"  
ID=ubuntu-core  
PRETTY_NAME="Ubuntu Core 18"  
VERSION_ID="18"  
HOME_URL="https://snapcraft.io/"  
BUG_REPORT_URL="http://bugs.launchpad.net/snappy/"  
  
**/greengrass** doesn't exist

Failure to build and run GGC in Docker on Ubuntu Core

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