I have a Raspberry Pi 2 running Raspian (Debian 9 Stretch Arm). I want to create a Chroot environment of pure Debian Stretch, and install Docker there. I follow all the proper instructions from here: https://docs.docker.com/install/linux/docker-ce/debian

When it comes time to install docker-ce, Aptitude says I'm missing some libraries (like libc6), but I believe the libraries are there and not being recognized. This would seem a to be very simple process, but I'm hitting a giant barrier.

I recorded a video of the install
https://youtu.be/wMmZGxZOBbs

Here are the commands I executed (all ran as root):

mkdir d

debootstrap stretch d

mount -B /dev d/dev

mount -B /dev/pts d/dev/pts

mount -B /proc d/proc

mount -B /sys d/sys

chroot d /bin/bash

chroot'd

nano /etc/apt/sources.list # add contrib and non-free

apt-get update

apt-get install aptitude

apt-get install bash-completion

apt-get install 

    apt-transport-https 

    ca-certificates 

    curl 

    gnupg2 

    software-properties-common

curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add -

add-apt-repository 

   "deb [arch=armhf] https://download.docker.com/linux/debian 

   $(lsb_release -cs) 

   stable"

apt-get update

apt-get install docker-ce # Fails, says package unavailable

aptitude # Try to install docker in aptitude shows missings libraries

UPDATE:

When running the convenience script, I receive this output:

root@pi2:/# curl -fsSL https://get.docker.com -o get-docker.sh

root@pi2:/# sh get-docker.sh

# Executing docker install script, commit: 4957679

+ sh -c apt-get update -qq >/dev/null

+ sh -c apt-get install -y -qq apt-transport-https ca-certificates curl >/dev/null

+ sh -c curl -fsSL "https://download.docker.com/linux/debian/gpg" | apt-key add -qq - >/dev/null

Warning: apt-key output should not be parsed (stdout is not a terminal)

+ sh -c echo "deb [arch=armel] https://download.docker.com/linux/debian stretch edge" > /etc/apt/sources.list.d/docker.list

+ sh -c apt-get update -qq >/dev/null

+ sh -c apt-get install -y -qq --no-install-recommends docker-ce >/dev/null

E: Unable to locate package docker-ce

Running apt-get update shows that the repository "doesn't support architecture 'armel'".

UPDATE2

Thanks to the answer from AB, it may not entirely solve the problem, but I'm definitely making great progress.

# ### Architecture Output from Debian Chroot

# dpkg --print-architecture

    armel

and

# ### Architecture Output from Raspian

# dpkg --print-architecture

    armhf

# lsb_release -cs # My system is up to date

    stretch

# debootstrap --arch=armhf stetch d

E: No such script: /usr/share/debootstrap/scripts/stetch

UPDATE3

I found that it's possible to install Debian architechture Armhf by using the following command.

# debootstrap --foreign --arch=armhf stretch dir

UPDATE4 SOLUTION

I successfully installed docker by forcing Debian to install as architecture armhf. Here are the steps I used to install Debian as architecture armhf.

mkdir d

debootstrap --foreign --arch=armhf stretch d

cat /etc/resolv.conf > d/etc/resolv.conf

chroot d /bin/bash

./debootstrap/debootstrap --second-stage

apt-get clean

After that, I follow the process of installing docker on Debian as normal.

TL;DR: you cannot install Docker's docker-ce package on armel architecture, but your system, being a Rasberry Pi 2, should be running armhf anyway, so there's something wrong in your setup.

Docker's requirements for Debian:

OS requirements

To install Docker CE, you need the 64-bit version of one of these
Debian or Raspbian versions:

• Buster 10


• Stretch 9 (stable) / Raspbian Stretch

Docker CE is supported on x86_64 (or amd64), armhf, and arm64
architectures.
on your system
The text is a bit misleading, since armhf is supported and 32 bits. Anyway, as your system is using the armel architecture and not the armhf, there is no package available from docker.com. That is why whatever you try, you won't be able to follow their guide and install Docker.

What you can check first:

• 
  

  Verify if your system (outside of chroot) is using armel or armhf with dpkg --print-architecture. If the answer is armhf then your debootstrap command went wrong and you should try again with the --arch=armhf option. UPDATE: that was it for OP, but it appears --foreign was also needed along, so this command made it:

  
  
  

  debootstrap --foreign --arch=armhf stretch d
  
  

  
  



• UPDATE: verify that the kernel is also an armhf kernel. Does it say armv7-something (probably armv7l) somewhere? or only arm or armv6-something ? It's possible that only the kernel isn't the correct one. If that's not an armv7 one you should consider changing it. Else this is an unexplainable bug with debootstrap, since I couldn't reproduce it on an other armhf platform.

Historical ideas to work around this issue below:

• Check if your hardware supports armhf, and reinstall it using armhf instead of armel. Wikipedia tells the CPU for a Raspberry Pi 2 is at least an ARM Cortex-A7 so suitable for armhf as this (outdated) Debian page and its link to a Debian developper's blog confirm. The raspbian repository provides only armhf not armel. So there's no reason armel should be seen at all and it's quite puzzling.

What else can perhaps, but not easily anyway, be done else:

• an other solution, out of scope for its difficulty here, if it does support armhf, would be to complete the missing multi-arch libraries required to install Docker.


• Debian does ship for the as-of-now-unreleased future Debian 10 the equivalent docker.io package, available for armel (but it tells: "Using docker.io on non-amd64 hosts is not supported at this time"). So one can imagine that when Raspbian follows, this package can become available. Don't expect bleeding edge versions anyway.


• It's probably possible to rebuild from sources those Docker packages for the armel architecture. This requires anyway knowledge you probably don't have yet.

Even if you get it installed on armel please consider that anything you'll try to pull from Docker Hub will be incompatible: if Docker doesn't provide armel chances are there will be no armel ecosystem at all.