Install rclone on a Go-less system using Go in Docker

rclone-build.sh

#! /usr/bin/env bash
#
# Install rclone on a Go-less system using Go in Docker.
#
set -ex

# latest stable release
RC_TAG=v1.64.2
GO_VER=1-bookworm

main() {
    src
    cd rclone.git
    git switch --detach $RC_TAG

    img
    bld
    #tst
    ins

    cd ..
    cln
}

src() {
    ! test -d rclone.git ||return 0
    git clone git@github.com:rclone/rclone.git rclone.git
}

img() {
    docker pull golang:$GO_VER
    docker build -t build-rclone - <<-EOF
	FROM golang:$GO_VER

	# give make build proper perms in .:/rclone
	RUN useradd --uid $UID --user-group \
	    --create-home --shell /bin/bash $USER

	# build static binary
	ENV CGO_ENABLED=0

	WORKDIR /rclone
	EOF
}

bld() {
    docker run --rm \
      --volume "$PWD:/rclone" \
      --user "$UID:$UID" \
      build-rclone \
      go build
      #make
}

tst() {
    docker run --rm \
      --volume "$PWD:/rclone" \
      --user "$UID:$UID" \
      build-rclone \
      make test
}

ins() {
    mkdir --parents ~/.local/bin
    cp --force --preserve rclone ~/.local/bin/
}

cln() {
    rm --force --recursive rclone.git
    docker image rm build-rclone
}

main
exit 0