#!/bin/bash
# This file is part of cloud-init. See LICENSE file for license information.

set -u

VERBOSITY=0
TEMP_D=""
KEEP=false
CONTAINER=""

error() { echo "$@" 1>&2; }
fail() { [ $# -eq 0 ] || error "$@"; exit 1; }
errorrc() { local r=$?; error "$@" "ret=$r"; return $r; }

Usage() {
    cat <<EOF
Usage: ${0##*/} [ options ] version

    This utility can makes it easier to run tests, build rpm and source rpm
        generation inside a LXC of the specified version of CentOS.

    version is major release number (6 or 7)

    options:
      -a | --artifact keep .rpm artifacts
           --dirty    apply local changes before running tests.
                      If not provided, a clean checkout of branch is tested.
                      Inside container, changes are in local-changes.diff.
      -k | --keep     keep container after tests
      -r | --rpm      build .rpm
      -s | --srpm     build .src.rpm
      -u | --unittest run unit tests

    Example:
      * ${0##*/} --rpm --srpm --unittest 6
EOF
}

bad_Usage() { Usage 1>&2; [ $# -eq 0 ] || error "$@"; return 1; }
cleanup() {
    if [ -n "$CONTAINER" -a "$KEEP" = "false" ]; then
        delete_container "$CONTAINER"
    fi
    [ -z "${TEMP_D}" -o ! -d "${TEMP_D}" ] || rm -Rf "${TEMP_D}"
}

debug() {
    local level=${1}; shift;
    [ "${level}" -gt "${VERBOSITY}" ] && return
    error "${@}"
}


inside_as() {
    # inside_as(container_name, user, cmd[, args])
    # executes cmd with args inside container as user in users home dir.
    local name="$1" user="$2"
    shift 2
    if [ "$user" = "root" ]; then
        inside "$name" "$@"
        return
    fi
    local stuffed="" b64=""
    stuffed=$(getopt --shell sh --options "" -- -- "$@")
    stuffed=${stuffed# -- }
    b64=$(printf "%s\n" "$stuffed" | base64 --wrap=0)
    inside "$name" su "$user" -c \
        'cd; eval set -- "$(echo '$b64' | base64 --decode)" && exec "$@"'
}

inside_as_cd() {
    local name="$1" user="$2" dir="$3"
    shift 3
    inside_as "$name" "$user" sh -c 'cd "$0" && exec "$@"' "$dir" "$@"
}

inside() {
    local name="$1"
    shift
    lxc exec "$name" -- "$@"
}

inject_cloud_init(){
    # take current cloud-init git dir and put it inside $name at
    # ~$user/cloud-init.
    local name="$1" user="$2" dirty="$3"
    local changes="" top_d="" dname="cloud-init" pstat=""
    local gitdir="" commitish=""
    gitdir=$(git rev-parse --git-dir) || {
        errorrc "Failed to get git dir in $PWD";
        return
    }
    local t=${gitdir%/*}
    case "$t" in
        */worktrees) 
            if [ -f "${t%worktrees}/config" ]; then
                gitdir="${t%worktrees}"
            fi
    esac

    # attempt to get branch name.
    commitish=$(git rev-parse --abbrev-ref HEAD) || {
        errorrc "Failed git rev-parse --abbrev-ref HEAD"
        return
    }
    if [ "$commitish" = "HEAD" ]; then
        # detached head
        commitish=$(git rev-parse HEAD) || {
            errorrc "failed git rev-parse HEAD"
            return
        }
    fi

    local local_changes=false
    if ! git diff --quiet "$commitish"; then
        # there are local changes not committed.
        local_changes=true
        if [ "$dirty" = "false" ]; then
            error "WARNING: You had uncommitted changes.  Those changes will "
            error "be put into 'local-changes.diff' inside the container. "
            error "To test these changes you must pass --dirty."
        fi
    fi

    debug 1 "collecting ${gitdir} ($dname) into user $user in $name."
    tar -C "${gitdir}" -cpf - . |
        inside_as "$name" "$user" sh -ec '
            dname=$1
            commitish=$2
            rm -Rf "$dname"
            mkdir -p $dname/.git
            cd $dname/.git
            tar -xpf -
            cd ..
            git config core.bare false
            out=$(git checkout $commitish 2>&1) ||
                { echo "failed git checkout $commitish: $out" 1>&2; exit 1; }
            out=$(git checkout . 2>&1) ||
                { echo "failed git checkout .: $out" 1>&2; exit 1; }
            ' extract "$dname" "$commitish"
    [ "${PIPESTATUS[*]}" = "0 0" ] || {
        error "Failed to push tarball of '$gitdir' into $name" \
            " for user $user (dname=$dname)"
        return 1
    }

    echo "local_changes=$local_changes dirty=$dirty"
    if [ "$local_changes" = "true" ]; then
        git diff "$commitish" |
            inside_as "$name" "$user" sh -exc '
                cd "$1"
                if [ "$2" = "true" ]; then
                    git apply
                else
                    cat > local-changes.diff
                fi
                ' insert_changes "$dname" "$dirty"
        [ "${PIPESTATUS[*]}" = "0 0" ] || {
            error "Failed to apply local changes."
            return 1
        }
    fi

    return 0
}

prep() {
    # we need some very basic things not present in the container.
    #  - git
    #  - tar (CentOS 6 lxc container does not have it)
    #  - python-argparse (or python3)
    local needed="" pair="" pkg="" cmd="" needed=""
    for pair in tar:tar git:git; do
        pkg=${pair#*:}
        cmd=${pair%%:*}
        command -v $cmd >/dev/null 2>&1 || needed="${needed} $pkg"
    done
    if ! command -v python3; then
        python -c "import argparse" >/dev/null 2>&1 ||
            needed="${needed} python-argparse"
    fi
    needed=${needed# }
    if [ -z "$needed" ]; then
        error "No prep packages needed"
        return 0
    fi
    error "Installing prep packages: ${needed}"
    set -- $needed
    local n max r
    n=0; max=10;
    bcmd="yum install --downloadonly --assumeyes --setopt=keepcache=1"
    while n=$(($n+1)); do
       error ":: running $bcmd $* [$n/$max]"
       $bcmd "$@"
       r=$?
       [ $r -eq 0 ] && break
       [ $n -ge $max ] && { error "gave up on $bcmd"; exit $r; }
       nap=$(($n*5))
       error ":: failed [$r] ($n/$max). sleeping $nap."
       sleep $nap
    done
    error ":: running yum install --cacheonly --assumeyes $*"
    yum install --cacheonly --assumeyes "$@"
}

start_container() {
    local src="$1" name="$2"
    debug 1 "starting container $name from '$src'"
    lxc launch "$src" "$name" || {
        errorrc "Failed to start container '$name' from '$src'";
        return
    }
    CONTAINER=$name

    local out="" ret=""
    debug 1 "waiting for networking"
    out=$(inside "$name" sh -c '
        i=0
        while [ $i -lt 60 ]; do
            getent hosts mirrorlist.centos.org && exit 0
            sleep 2
        done' 2>&1)
    ret=$?
    if [ $ret -ne 0 ]; then
        error "Waiting for network in container '$name' failed. [$ret]"
        error "$out"
        return $ret
    fi

    if [ ! -z "${http_proxy-}" ]; then
        debug 1 "configuring proxy ${http_proxy}"
        inside "$name" sh -c "echo proxy=$http_proxy >> /etc/yum.conf"
        inside "$name" sed -i s/enabled=1/enabled=0/ /etc/yum/pluginconf.d/fastestmirror.conf
    fi
}

delete_container() {
    debug 1 "removing container $1 [--keep to keep]"
    lxc delete --force "$1"
}

main() {
    local short_opts="ahkrsuv"
    local long_opts="artifact,dirty,help,keep,rpm,srpm,unittest,verbose"
    local getopt_out=""
    getopt_out=$(getopt --name "${0##*/}" \
        --options "${short_opts}" --long "${long_opts}" -- "$@") &&
        eval set -- "${getopt_out}" ||
        { bad_Usage; return; }

    local cur="" next=""
    local artifact="" keep="" rpm="" srpm="" unittest="" version=""
    local dirty=false

    while [ $# -ne 0 ]; do
        cur="${1:-}"; next="${2:-}";
        case "$cur" in
            -a|--artifact) artifact=1;;
               --dirty) dirty=true;;
            -h|--help) Usage ; exit 0;;
            -k|--keep) KEEP=true;;
            -r|--rpm) rpm=1;;
            -s|--srpm) srpm=1;;
            -u|--unittest) unittest=1;;
            -v|--verbose) VERBOSITY=$((${VERBOSITY}+1));;
            --) shift; break;;
        esac
        shift;
    done

    [ $# -eq 1 ] || { bad_Usage "ERROR: Must provide version!"; return; }
    version="$1"
    case "$version" in
        6|7) :;;
        *) error "Expected version of 6 or 7, not '$version'"; return;;
    esac

    TEMP_D=$(mktemp -d "${TMPDIR:-/tmp}/${0##*/}.XXXXXX") ||
        fail "failed to make tempdir"
    trap cleanup EXIT

    # program starts here
    local uuid="" name="" user="ci-test" cdir=""
    cdir="/home/$user/cloud-init"
    uuid=$(uuidgen -t) || { error "no uuidgen"; return 1; }
    name="cloud-init-centos-${uuid%%-*}"

    start_container "images:centos/$version" "$name"

    # prep the container (install very basic dependencies)
    inside "$name" bash -s prep <"$0" ||
        { errorrc "Failed to prep container $name"; return; }

    # add the user
    inside "$name" useradd "$user"

    debug 1 "inserting cloud-init"
    inject_cloud_init "$name" "$user" "$dirty" || {
        errorrc "FAIL: injecting cloud-init into $name failed."
        return
    }

    inside_as_cd "$name" root "$cdir" \
        ./tools/read-dependencies --distro=centos --test-distro || {
        errorrc "FAIL: failed to install dependencies with read-dependencies"
        return
    }

    local errors=0
    inside_as_cd "$name" "$user" "$cdir" \
        sh -ec "git status" ||
            { errorrc "git checkout failed."; errors=$(($errors+1)); }

    if [ -n "$unittest" ]; then
        debug 1 "running unit tests."
        inside_as_cd "$name" "$user" "$cdir" \
            nosetests tests/unittests cloudinit ||
            { errorrc "nosetests failed."; errors=$(($errors+1)); }
    fi

    if [ -n "$srpm" ]; then
        debug 1 "building srpm."
        inside_as_cd "$name" "$user" "$cdir" ./packages/brpm --srpm ||
            { errorrc "brpm --srpm."; errors=$(($errors+1)); }
    fi

    if [ -n "$rpm" ]; then
        debug 1 "building rpm."
        inside_as_cd "$name" "$user" "$cdir" ./packages/brpm ||
            { errorrc "brpm failed."; errors=$(($errors+1)); }
    fi

    if [ -n "$artifact" ]; then
        for built_rpm in $(inside "$name" sh -c "echo $cdir/*.rpm"); do
            lxc file pull "$name/$built_rpm" .
        done
    fi

    if [ "$errors" != "0" ]; then
        error "there were $errors errors."
        return 1
    fi
    return 0
}

if [ "${1:-}" = "prep" ]; then
    shift
    prep "$@"
else
    main "$@"
fi
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