Cross building Docker for armv7 in Ubuntu 20.04

[Mikko Kiilholma]

Hi,

My name  is Mikko, I am software developer from Tampere, Finland.

I am trying to build Docker release 18.09.9 in Ubuntu 20.04.

I have cloned https://github.com/docker/docker.git.

I use command: sudo make DOCKER_CROSSPLATFORMS=linux/arm/v7 cross

... but it fails:

 => ERROR [gotestsum 3/3] RUN PREFIX=/build ./install.sh gotestsum

------

 > [gotestsum 3/3] RUN PREFIX=/build ./install.sh gotestsum:

#27 2.453 + RM_GOPATH=0

#27 2.453 + TMP_GOPATH=

#27 2.453 + : /build

#27 2.453 + '[' -z '' ']'

#27 2.454 ++ mktemp -d

#27 2.455 + export GOPATH=/tmp/tmp.3BKIwbdYJf

#27 2.455 + GOPATH=/tmp/tmp.3BKIwbdYJf

#27 2.455 + RM_GOPATH=1

#27 2.455 ++ dirname ./install.sh

#27 2.458 + dir=.

#27 2.458 + bin=gotestsum

#27 2.458 + shift

#27 2.458 + '[' '!' -f ./gotestsum.installer ']'

#27 2.458 + . ./gotestsum.installer

#27 2.467 ++ GOTESTSUM_COMMIT=v0.3.5

#27 2.467 + install_gotestsum

#27 2.467 + echo 'Installing gotestsum version v0.3.5'

#27 2.467 + go get -d gotest.tools/gotestsum

#27 2.467 Installing gotestsum version v0.3.5

#27 80.96 + cd /tmp/tmp.3BKIwbdYJf/src/gotest.tools/gotestsum

#27 80.97 + git checkout -q v0.3.5

#27 81.09 + go build -buildmode=pie -o /build/gotestsum gotest.tools/gotestsum

#27 81.60 handler.go:8:2: cannot find package "github.com/sirupsen/logrus" in any of:

#27 81.60       /usr/local/go/src/github.com/sirupsen/logrus (from $GOROOT)

#27 81.60       /tmp/tmp.3BKIwbdYJf/src/github.com/sirupsen/logrus (from $GOPATH)

#27 81.60 main.go:14:2: cannot find package "github.com/spf13/pflag" in any of:

#27 81.60       /usr/local/go/src/github.com/spf13/pflag (from $GOROOT)

#27 81.60       /tmp/tmp.3BKIwbdYJf/src/github.com/spf13/pflag (from $GOPATH)

------

executor failed running [/bin/sh -c PREFIX=/build ./install.sh $INSTALL_BINARY_NAME]: exit code: 1

make: *** [Makefile:144: build] Error 1

How can I fix this?

I have tried the prebuilt binaries of the release from https://download.docker.com/linux/static/stable/armhf/ 

But it does not start. It tries to create folder /opt but it is read only in my system.

This is why I try to do some changes and build it myself.

- Mikko