#!/bin/bash

set -xeuo pipefail

DOCKER_VERSION=${1}

function build_debian() {
    export DEBIAN_FRONTEND=noninteractive
    DEBIAN_VERSION=$(lsb_release -c -s)

    apt-get update
    apt-get -y install \
        apt-transport-https \
        ca-certificates \
        curl \
        gnupg

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

    echo "deb [arch=amd64] https://download.docker.com/linux/debian ${DEBIAN_VERSION} stable" >> /etc/apt/sources.list.d/docker.list
    apt-get update

    PACKAGE_VERSION=$(apt-cache policy docker-ce | awk -v dv=${DOCKER_VERSION}~ '$1 ~ dv {print $1}')

    apt-get install -y docker-ce=${PACKAGE_VERSION} docker-ce-cli=${PACKAGE_VERSION}
    apt-get -yq autoremove
    apt-get clean -yqq
    rm -rf /var/lib/apt/lists/*
}

function build_ubi() {
    yum update -y
    yum install -y yum-utils

    # Docker only provides s390x packages for RHEL. For remaining
    # architectures, they recommend using the CentOS repo.
    yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
    yum update -y

    PACKAGE_VERSION=$(yum --showduplicates list docker-ce | awk -v dv=${DOCKER_VERSION} '$2 ~ dv {print $2}')
    # Epoch can differ between docker-ce and docker-cli versions.
    VERSION_WITHOUT_EPOCH=${PACKAGE_VERSION#*:}
    CLI_VERSION=$(yum --showduplicates list docker-ce-cli | awk -v dv=${VERSION_WITHOUT_EPOCH} '$2 ~ dv {print $2}')

    yum install -y docker-ce-${PACKAGE_VERSION} docker-ce-cli-${CLI_VERSION}

    yum autoremove -y
    yum clean -y all
}

BUILD_OS=${BUILD_OS:-debian}
BUILD_ARCH=${BUILD_ARCH:-amd64}

if [[ $BUILD_OS =~ debian ]]; then
    build_debian "$@"
elif [[ $BUILD_OS =~ ubi ]]; then
    build_ubi "$@"
fi