#!/bin/sh
#
# ds-identify is configured via /etc/cloud/ds-identify.cfg
# or on the kernel command line. It takes primarily 2 inputs:
# datasource: can specify the datasource that should be used.
#     kernel command line option: ci.datasource=<dsname>
#  
# policy: a string that indicates how ds-identify should operate.
#     kernel command line option: ci.di.policy=<policy>
#   default setting is:
#     search,found=all,maybe=all,notfound=disable

#   report: write config to /run/cloud-init/cloud.cfg.report (instead of
#           /run/cloud-init/cloud.cfg, which effectively makes this dry-run).
#   enable: do nothing
#      ds-identify writes no config and just exits success
#      the caller (cloud-init-generator) then enables cloud-init to run
#      just without any aid from ds-identify.
#   disable: disable cloud-init
#
#   [report,]found=value,maybe=value,notfound=value
#      found: (default=first)
#         first: use the first found do no further checking
#         all: enable all DS_FOUND
#
#      maybe: (default=all)
#       if nothing returned 'found', then how to handle maybe.
#       no network sources are allowed to return 'maybe'.
#         all: enable all DS_MAYBE
#         none: ignore any DS_MAYBE
#
#      notfound: (default=disable)
#         disable: disable cloud-init
#         enable: enable cloud-init
#
#
# zesty:
#    policy: found=first,maybe=all,none=disable
# xenial:
#      policy: found=all,maybe=all,none=enable
#    and then at a later date


set -u
set -f
UNAVAILABLE="unavailable"
CR="
"
ERROR="error"
DI_ENABLED="enabled"
DI_DISABLED="disabled"

DI_DEBUG_LEVEL="${DEBUG_LEVEL:-1}"

PATH_ROOT=${PATH_ROOT:-""}
PATH_RUN=${PATH_RUN:-"${PATH_ROOT}/run"}
PATH_SYS_CLASS_DMI_ID=${PATH_SYS_CLASS_DMI_ID:-${PATH_ROOT}/sys/class/dmi/id}
PATH_SYS_HYPERVISOR=${PATH_SYS_HYPERVISOR:-${PATH_ROOT}/sys/hypervisor}
PATH_SYS_CLASS_BLOCK=${PATH_SYS_CLASS_BLOCK:-${PATH_ROOT}/sys/class/block}
PATH_DEV_DISK="${PATH_DEV_DISK:-${PATH_ROOT}/dev/disk}"
PATH_VAR_LIB_CLOUD="${PATH_VAR_LIB_CLOUD:-${PATH_ROOT}/var/lib/cloud}"
PATH_DI_CONFIG="${PATH_DI_CONFIG:-${PATH_ROOT}/etc/cloud/ds-identify.cfg}"
PATH_PROC_CMDLINE="${PATH_PROC_CMDLINE:-${PATH_ROOT}/proc/cmdline}"
PATH_PROC_1_CMDLINE="${PATH_PROC_1_CMDLINE:-${PATH_ROOT}/proc/1/cmdline}"
PATH_CLOUD_CONFD="${PATH_CLOUD_CONFD:-${PATH_ROOT}/etc/cloud}"
PATH_RUN_CI="${PATH_RUN_CI:-${PATH_RUN}/cloud-init}"
PATH_RUN_CI_CFG=${PATH_RUN_CI_CFG:-${PATH_RUN_CI}/cloud.cfg}

DI_LOG="${DI_LOG:-${PATH_RUN_CI}/ds-identify.log}"
_DI_LOGGED=""

# set DI_MAIN='noop' in environment to source this file with no main called.
DI_MAIN=${DI_MAIN:-main}

DI_DEFAULT_POLICY="search,found=all,maybe=all,notfound=${DI_DISABLED}"
DI_DEFAULT_POLICY_NO_DMI="search,found=all,maybe=all,notfound=${DI_ENABLED}"
DI_DMI_PRODUCT_NAME=""
DI_DMI_SYS_VENDOR=""
DI_DMI_PRODUCT_SERIAL=""
DI_DMI_PRODUCT_UUID=""
DI_FS_LABELS=""
DI_KERNEL_CMDLINE=""
DI_VIRT=""

DI_UNAME_KERNEL_NAME=""
DI_UNAME_KERNEL_RELEASE=""
DI_UNAME_KERNEL_VERSION=""
DI_UNAME_MACHINE=""
DI_UNAME_NODENAME=""
DI_UNAME_OPERATING_SYSTEM=""
DI_UNAME_CMD_OUT=""

DS_FOUND=0
DS_NOT_FOUND=1
DS_MAYBE=2

DI_DSNAME=""
# this has to match the builtin list in cloud-init, it is what will
# be searched if there is no setting found in config.
DI_DSLIST_DEFAULT="MAAS ConfigDrive NoCloud AltCloud Azure Bigstep \
CloudSigma CloudStack DigitalOcean Ec2 OpenNebula OpenStack OVF SmartOS"
DI_DSLIST=""
DI_MODE=""
DI_REPORT=""
DI_ON_FOUND=""
DI_ON_MAYBE=""
DI_ON_NOTFOUND=""


error() {
    set -- "ERROR:" "$@";
    debug 0 "$@"
    stderr "$@"
}
warn() {
    set -- "WARN:" "$@"
    debug 0 "$@"
    stderr "$@"
}

stderr() { echo "$@" 1>&2; }

debug() {
    local lvl="$1"
    shift
    [ "$lvl" -gt "${DI_DEBUG_LEVEL}" ] && return

    if [ "$_DI_LOGGED" != "$DI_LOG" ]; then
        # first time here, open file descriptor for append
        case "$DI_LOG" in
            stderr) :;;
            ?*/*)
                if [ ! -d "${DI_LOG%/*}" ]; then
                    mkdir -p "${DI_LOG%/*}" || {
                        stderr "ERROR:" "cannot write to $DI_LOG"
                        DI_LOG="stderr"
                    }
                fi
        esac
        if [ "$DI_LOG" = "stderr" ]; then
            exec 3>&2
        else
            ( exec 3>>"$DI_LOG" ) && exec 3>>"$DI_LOG" || {
                stderr "ERROR: failed writing to $DI_LOG. logging to stderr.";
                exec 3>&2
                DI_LOG="stderr"
            }
        fi
        _DI_LOGGED="$DI_LOG"
    fi
    echo "$@" 1>&3
}

get_dmi_field() {
    local path="${PATH_SYS_CLASS_DMI_ID}/$1"
    if [ ! -f "$path" ] || [ ! -r "$path" ]; then
        _RET="$UNAVAILABLE"
        return
    fi
    read _RET < "${path}" || _RET="$ERROR"
}

block_dev_with_label() {
    local p="${PATH_DEV_DISK}/by-label/$1"
    [ -b "$p" ] || return 1
    _RET=$p
    return 0
}

read_fs_labels() {
    cached "${DI_FS_LABELS}" && return 0
    # do not rely on links in /dev/disk which might not be present yet.
    # note that older blkid versions do not report DEVNAME in 'export' output.
    local out="" ret=0 oifs="$IFS" line="" delim=","
    local labels=""
    if is_container; then
        # blkid will in a container, or at least currently in lxd
        # not provide useful information.
        DI_FS_LABELS="$UNAVAILABLE:container"
    else
        out=$(blkid -c /dev/null -o export) || {
            ret=$?
            error "failed running [$ret]: blkid -c /dev/null -o export"
            return $ret
        }
        IFS="$CR"
        set -- $out
        IFS="$oifs"
        for line in "$@"; do
            case "${line}" in
                LABEL=*) labels="${labels}${line#LABEL=}${delim}";;
            esac
        done
        DI_FS_LABELS="${labels%${delim}}"
    fi
}

cached() {
    [ -n "$1" ] && _RET="$1" && return || return 1
}


has_cdrom() {
    [ -e "${PATH_ROOT}/dev/cdrom" ]
}

read_virt() {
    cached "$DI_VIRT" && return 0
    local out="" r="" virt="${UNAVAILABLE}"
    if [ -d /run/systemd ]; then
        out=$(systemd-detect-virt 2>&1)
        r=$?
        if [ $r -eq 0 ] || { [ $r -ne 0 ] && [ "$out" = "none" ]; }; then
            virt="$out"
        fi
    fi
    DI_VIRT=$virt
}

is_container() {
    case "${DI_VIRT}" in
        lxc|lxc-libvirt|systemd-nspawn|docker|rkt) return 0;;
        *) return 1;;
    esac
}

read_kernel_cmdline() {
    cached "${DI_KERNEL_CMDLINE}" && return
    local cmdline="" fpath="${PATH_PROC_CMDLINE}"
    if is_container; then
        local p1path="${PATH_PROC_1_CMDLINE}" x=""
        cmdline="${UNAVAILABLE}:container"
        if [ -f "$p1path" ] && x=$(tr '\0' ' ' < "$p1path"); then
            cmdline=$x
        fi
    elif [ -f "$fpath" ]; then
        read cmdline <"$fpath"
    else
        cmdline="${UNAVAILABLE}:no-cmdline"
    fi
    DI_KERNEL_CMDLINE="$cmdline"
}

read_dmi_sys_vendor() {
    cached "${DI_DMI_SYS_VENDOR}" && return
    get_dmi_field sys_vendor
    DI_DMI_SYS_VENDOR="$_RET"
}

read_dmi_product_name() {
    cached "${DI_DMI_PRODUCT_NAME}" && return
    get_dmi_field product_name
    DI_DMI_PRODUCT_NAME="$_RET"
}

read_dmi_product_uuid() {
    cached "${DI_DMI_PRODUCT_UUID}" && return
    get_dmi_field product_uuid
    DI_DMI_PRODUCT_UUID="$_RET"
}

read_dmi_product_serial() {
    cached "${DI_DMI_PRODUCT_SERIAL}" && return
    get_dmi_field product_serial
    DI_DMI_PRODUCT_SERIAL="$_RET"
}

read_uname_info() {
    # run uname, and parse output.
    # uname is tricky to parse as it outputs always in a given order
    # independent of option order. kernel-version is known to have spaces.
    # 1   -s kernel-name
    # 2   -n nodename
    # 3   -r kernel-release
    # 4.. -v kernel-version(whitespace)
    # N-2 -m machine
    # N-1 -o operating-system
    cached "${DI_UNAME_CMD_OUT}" && return
    local out="${1:-}" ret=0 buf=""
    if [ -z "$out" ]; then
        out=$(uname -snrvmo) || {
            ret=$?
            error "failed reading uname with 'uname -snrvmo'"
            return $ret
        }
    fi
    set -- $out
    DI_UNAME_KERNEL_NAME="$1"
    DI_UNAME_NODENAME="$2"
    DI_UNAME_KERNEL_RELEASE="$3"
    shift 3
    while [ $# -gt 2 ]; do
        buf="$buf $1"
        shift
    done
    DI_UNAME_KERNEL_VERSION="${buf# }"
    DI_UNAME_MACHINE="$1"
    DI_UNAME_OPERATING_SYSTEM="$2"
    DI_UNAME_CMD_OUT="$out"
    return 0
}

parse_yaml_array() {
    # parse a yaml single line array value ([1,2,3], not key: [1,2,3]).
    # supported with or without leading and closing brackets
    #   ['1'] or [1]
    #   '1', '2'
    local val="$1" oifs="$IFS" ret="" tok=""
    val=${val#[}
    val=${val%]}
    IFS=","; set -- $val; IFS="$oifs"
    for tok in "$@"; do
        trim "$tok"
        unquote "$_RET"
        ret="${ret} $_RET"
    done
    _RET="${ret# }"
}

read_datasource_list() {
    cached "$DI_DSLIST" && return
    local dslist=""
    # if DI_DSNAME is set directly, then avoid parsing config.
    if [ -n "${DI_DSNAME}" ]; then
        dslist="${DI_DSNAME}"
    fi

    # LP: #1582323. cc:{'datasource_list': ['name']}
    # more generically cc:<yaml>[end_cc]
    local cb="]" ob="["
    case "$DI_KERNEL_CMDLINE" in
        *cc:*datasource_list*)
            t=${DI_KERNEL_CMDLINE##*datasource_list}
            t=${t%%$cb*}
            t=${t##*$ob}
            parse_yaml_array "$t"
            dslist=${_RET}
            ;;
    esac
    if [ -z "$dslist" ] && check_config datasource_list; then
        debug 1 "$_RET_fname set datasource_list: $_RET"
        parse_yaml_array "$_RET"
        dslist=${_RET}
    fi
    if [ -z "$dslist" ]; then
        dslist=${DI_DSLIST_DEFAULT}
        debug 1 "no datasource_list found, using default:" $dslist
    fi
    DI_DSLIST=$dslist
    return 0
}

dmi_product_name_matches() {
    is_container && return 1
    case "${DI_DMI_PRODUCT_NAME}" in
        $1) return 0;;
    esac
    return 1
}

dmi_product_name_is() {
    is_container && return 1
    [ "${DI_DMI_PRODUCT_NAME}" = "$1" ]
}

dmi_sys_vendor_is() {
    is_container && return 1
    [ "${DI_DMI_SYS_VENDOR}" = "$1" ]
}

has_fs_with_label() {
    local label=",$1,"
    case "${DI_FS_LABELS}" in
        *,$label,*) return 0;;
    esac
    return 1
}

nocase_equal() {
    # nocase_equal(a, b)
    # return 0 if case insenstive comparision a.lower() == b.lower()
    # different lengths
    [ "${#1}" = "${#2}" ] || return 1
    # case sensitive equal
    [ "$1" = "$2" ] && return 0

    local delim="-delim-"
    out=$(echo "$1${delim}$2" | tr A-Z a-z)
    [ "${out#*${delim}}" = "${out%${delim}*}" ]
}

check_seed_dir() {
    # check_seed_dir(name, [required])
    # check the seed dir /var/lib/cloud/seed/<name> for 'required'
    # required defaults to 'meta-data'
    local name="$1"
    local dir="${PATH_VAR_LIB_CLOUD}/seed/$name"
    [ -d "$dir" ] || return 1
    shift
    if [ $# -eq 0 ]; then
        set -- meta-data
    fi
    local f=""
    for f in "$@"; do
        [ -f "$dir/$f" ] || return 1
    done
    return 0
}

probe_floppy() {
    cached "${STATE_FLOPPY_PROBED}" && return "${STATE_FLOPPY_PROBED}"
    local fpath=/dev/floppy

    [ -b "$fpath" ] ||
        { STATE_FLOPPY_PROBED=1; return 1; }

    modprobe --use-blacklist floppy >/dev/null 2>&1 ||
        { STATE_FLOPPY_PROBED=1; return 1; }

    udevadm settle "--exit-if-exists=$fpath" ||
        { STATE_FLOPPY_PROBED=1; return 1; }

    [ -b "$fpath" ]
    STATE_FLOPPY_PROBED=$?
    return "${STATE_FLOPPY_PROBED}"
}


dscheck_CloudStack() {
    is_container && return ${DS_NOT_FOUND}
    dmi_product_name_matches "CloudStack*" && return $DS_FOUND
    return $DS_NOT_FOUND
}

dscheck_CloudSigma() {
    # http://paste.ubuntu.com/23624795/
    dmi_product_name_is "CloudSigma" && return $DS_FOUND
    return $DS_NOT_FOUND
}

check_config() {
    # somewhat hackily read config for 'key' in files matching 'files'
    # currently does not respect any hierarchy.
    local key="$1" files="" bp="${PATH_CLOUD_CONFD}/cloud.cfg"
    if [ $# -eq 1 ]; then
        files="$bp ${bp}.d/*.cfg"
    else
        files="$*"
    fi
    shift
    set +f; set -- $files; set +f;
    if [ "$1" = "$files" -a ! -f "$1" ]; then
        return 1
    fi
    local fname="" line="" ret="" found=0 found_fn=""
    for fname in "$@"; do
        [ -f "$fname" ] || continue
        while read line; do
            line=${line%%#*}
            case "$line" in
                $key:\ *|$key:)
                    ret=${line#*:};
                    ret=${ret# };
                    found=$((found+1))
                    found_fn="$fname";;
            esac
        done <"$fname"
    done
    if [ $found -ne 0 ]; then
        _RET="$ret"
        _RET_fname="$found_fn"
        return 0
    fi
    return 1
}

dscheck_MAAS() {
    is_container && return "${DS_NOT_FOUND}"
    # heuristic check for ephemeral boot environment
    # for maas that do not set 'ci.dsname=' in the ephemeral environment
    # these have iscsi root and cloud-config-url on the cmdline.
    local maasiqn="iqn.2004-05.com.ubuntu:maas"
    case "${DI_KERNEL_CMDLINE}" in
        *cloud-config-url=*${maasiqn}*|*${maasiqn}*cloud-config-url=*)
            return ${DS_FOUND}
            ;;
    esac

    # check config files written by maas for installed system.
    local confd="${PATH_CLOUD_CONFD}"
    local fnmatch="$confd/*maas*.cfg $confd/*kernel_cmdline*.cfg"
    if check_config "MAAS" "$fnmatch"; then
        return "${DS_FOUND}"
    fi
    return ${DS_NOT_FOUND}
}

dscheck_NoCloud() {
    local fslabel="cidata" d=""
    for d in nocloud nocloud-net; do
        check_seed_dir "$d" meta-data user-data && return ${DS_FOUND}
    done
    if has_fs_with_label "${fslabel}"; then
        return ${DS_FOUND}
    fi
    return ${DS_NOT_FOUND}
}

check_configdrive_v2() {
    if has_fs_with_label "config-2"; then
        return ${DS_FOUND}
    fi
    return ${DS_NOT_FOUND}
}

check_configdrive_v1() {
    # FIXME: this has to check any file system that is vfat...
    # for now, just return not found.
    return ${DS_NOT_FOUND}
}

dscheck_ConfigDrive() {
    local ret=""
    check_configdrive_v2
    ret=$?
    [ $DS_FOUND -eq $ret ] && return $ret

    check_configdrive_v1
}

dscheck_DigitalOcean() {
    dmi_sys_vendor_is DigitalOcean && return ${DS_FOUND}
    return ${DS_NOT_FOUND}
}

dscheck_OpenNebula() {
    check_seed_dir opennebula && return ${DS_FOUND}
    has_fs_with_label "CONTEXT" && return ${DS_FOUND}
    return ${DS_NOT_FOUND}
}

dscheck_OVF() {
    local p=""
    check_seed_dir ovf ovf-env.xml && return "${DS_FOUND}"

    has_cdrom || return ${DS_NOT_FOUND}

    # FIXME: currently just return maybe if there is a cdrom
    # ovf iso9660 transport does not specify an fs label.
    # better would be to check if
    return ${DS_MAYBE}
}

dscheck_Azure() {
    # http://paste.ubuntu.com/23630873/
    # $ grep /sr0 /run/blkid/blkid.tab
    # <device DEVNO="0x0b00" TIME="1481737655.543841"
    #  UUID="112D211272645f72" LABEL="rd_rdfe_stable.161212-1209"
    #  TYPE="udf">/dev/sr0</device>
    #
    check_seed_dir azure ovf-env.xml && return ${DS_FOUND}

    [ "${DI_VIRT}" = "microsoft" ] || return ${DS_NOT_FOUND}

    has_fs_with_label "rd_rdfe_*" && return ${DS_FOUND}

    return ${DS_NOT_FOUND}
}

dscheck_Bigstep() {
    # bigstep is activated by presense of seed file 'url'
    check_seed_dir "bigstep" url && return ${DS_FOUND}
    return ${DS_NOT_FOUND}
}

dscheck_Ec2() {
    # http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html
    # http://paste.ubuntu.com/23630859/
    local uuid="" hvuuid="$PATH_ROOT/sys/hypervisor/uuid"
    is_container && return ${DS_NOT_FOUND}
    # if the (basically) xen specific /sys/hypervisor/uuid starts with 'ec2'
    if [ -r "$hvuuid" ] && read uuid < "$hvuuid" &&
        [ "${uuid#ec2}" != "$uuid" ]; then
        return ${DS_FOUND}
    fi

    # product uuid and product serial start with case insensitive
    local uuid=${DI_DMI_PRODUCT_UUID} serial=${DI_DMI_PRODUCT_SERIAL}
    case "$uuid:$serial" in
        [Ee][Cc]2*:[Ee][Cc]2)
            # both start with ec2, now check for case insenstive equal
            nocase_equal "$uuid" "$serial" && return ${DS_FOUND};;
    esac

    # search through config files to check for platform
    local f="" match="${PATH_CLOUD_CONFD}/*ec2*.cfg"
    # look for the key 'platform' (datasource/ec2/look_alike/behavior)
    if check_config platform "$match"; then
        if [ "$platform" != "Unknown" ]; then
            _RET="$name"
            return "${DS_FOUND}"
        fi
    fi

    return ${DS_NOT_FOUND}
}

dscheck_GCE() {
    if dmi_product_name_is "Google Compute Engine"; then
        return ${DS_FOUND}
    fi
    return ${DS_NOT_FOUND}
}

dscheck_OpenStack() {
    # the openstack metadata http service

    # if there is a config drive, then do not check metadata
    # FIXME: if config drive not in the search list, then we should not
    # do this check.
    check_configdrive_v2
    if [ $? -eq ${DS_FOUND} ]; then
        return ${DS_NOT_FOUND}
    fi
    if dmi_product_name_is "OpenStack Nova"; then
        return ${DS_FOUND}
    fi
    case "${DI_VIRT}" in
        lxc|lxc-libvirt)
            # FIXME: This could be container on openstack (nova-lxd)
            # or nova-libvirt-lxc
            return ${DS_NOT_FOUND}
            ;;
    esac

    return ${DS_NOT_FOUND}
}

dscheck_AliYun() {
    # aliyun is not enabled by default (LP: #1638931)
    # so if we are here, it is because the datasource_list was
    # set to include it.  Thus, 'maybe'.
    return $DS_MAYBE
}

dscheck_AltCloud() {
    # ctype: either the dmi product name, or contents of
    #        /etc/sysconfig/cloud-info
    # if ctype == "vsphere"
    #    device = device with label 'CDROM'
    # elif ctype == "rhev"
    #    device = /dev/floppy
    # then, filesystem on that device must have
    #    user-data.txt or deltacloud-user-data.txt
    local ctype="" dev=""
    local match_rhev="[Rr][Hh][Ee][Vv]"
    local match_vsphere="[Vv][Ss][Pp][Hh][Ee][Rr][Ee]"
    local cinfo="${PATH_ROOT}/etc/sysconfig/cloud-info"
    if [ -f "$cinfo" ]; then
        read ctype < "$cinfo"
    else
        ctype="${DI_DMI_PRODUCT_NAME}"
    fi
    case "$ctype" in
        ${match_rhev})
            probe_floppy || return ${DS_NOT_FOUND}
            dev="/dev/floppy"
            ;;
        ${match_vsphere})
            block_dev_with_label CDROM || return ${DS_NOT_FOUND}
            dev="$_RET"
            ;;
        *) return ${DS_NOT_FOUND};;
    esac

    # FIXME: need to check $dev for user-data.txt or deltacloud-user-data.txt
    : "$dev"
    return $DS_MAYBE
}

dscheck_SmartOS() {
    # joyent cloud has two virt types: kvm and container
    # on kvm, product name on joyent public cloud shows 'SmartDC HVM'
    # on the container platform, uname's version has: BrandZ virtual linux
    local smartdc_kver="BrandZ virtual linux"
    dmi_product_name_matches "SmartDC*" && return $DS_FOUND
    if [ "${DI_UNAME_KERNEL_VERSION}" = "${smartdc_kver}" ] &&
       [ "${DI_VIRT}" = "container-other" ]; then
       return ${DS_FOUND}
    fi
    return ${DS_NOT_FOUND}
}

dscheck_None() {
    return ${DS_NOT_FOUND}
}

collect_info() {
    read_virt
    read_kernel_cmdline
    read_uname_info
    read_config
    read_datasource_list
    read_dmi_sys_vendor
    read_dmi_product_name
    read_dmi_product_serial
    read_dmi_product_uuid
    read_fs_labels
}

print_info() {
    collect_info
    _print_info
}

_print_info() {
    local n="" v="" vars=""
    vars="DMI_PRODUCT_NAME DMI_SYS_VENDOR DMI_PRODUCT_SERIAL"
    vars="$vars DMI_PRODUCT_UUID"
    vars="$vars FS_LABELS KERNEL_CMDLINE VIRT"
    vars="$vars UNAME_KERNEL_NAME UNAME_KERNEL_RELEASE UNAME_KERNEL_VERSION"
    vars="$vars UNAME_MACHINE UNAME_NODENAME UNAME_OPERATING_SYSTEM"
    vars="$vars DSNAME DSLIST"
    vars="$vars MODE REPORT ON_FOUND ON_MAYBE ON_NOTFOUND"
    for v in ${vars}; do
        eval n='${DI_'"$v"'}'
        echo "$v=$n"
    done
    echo "pid=$$ ppid=$PPID"
    is_container && echo "is_container=true" || echo "is_container=false"
}

write_result() {
    local runcfg="${PATH_RUN_CI_CFG}" ret="" line=""
    if [ "$DI_REPORT" = "true" ]; then
        runcfg="$runcfg.report"
    fi
    for line in "$@"; do
        echo "$line"
    done > "$runcfg"
    ret=$?
    [ $ret -eq 0 ] || {
        error "failed to write to ${runcfg}"
        return $ret
    }
    return 0
}

found() {
    local list="" ds=""
    # always we write the None datasource last.
    for ds in "$@" None; do
        list="${list:+${list}, }$ds"
    done
    write_result "datasource_list: [ $list ]"
    return
}

trim() {
    set -- $*
    _RET="$*"
}

unquote() {
    # remove quotes from quoted value
    local quote='"' tick="'"
    local val="$1"
    case "$val" in
        ${quote}*${quote}|${tick}*${tick})
            val=${val#?}; val=${val%?};;
    esac
    _RET="$val"
}

_read_config() {
    # reads config from stdin, modifies _rc scoped environment vars.
    # rc_policy and _rc_dsname
    local line="" hash="#" ckey="" key="" val=""
    while read line; do
        line=${line%%${hash}*}
        key="${line%%:*}"

        # no : in the line.
        [ "$key" = "$line" ] && continue
        trim "$key"
        key=${_RET}

        val="${line#*:}"
        trim "$val"
        unquote "${_RET}"
        val=${_RET}
        case "$key" in
            datasource) _rc_dsname="$val";;
            policy) _rc_policy="$val";;
        esac
    done
}

parse_warn() {
    echo "WARN: invalid value '$2' for key '$1'. Using $1=$3." 1>&2
}

parse_def_policy() {
    local _rc_mode="" _rc_report="" _rc_found="" _rc_maybe="" _rc_notfound=""
    local ret=""
    parse_policy "$@"
    ret=$?
    _def_mode=$_rc_mode
    _def_report=$_rc_report
    _def_found=$_rc_found
    _def_maybe=$_rc_maybe
    _def_notfound=$_rc_notfound
    return $ret
}

parse_policy() {
    # parse_policy(policy, default)
    # parse a policy string.  sets
    #   _rc_mode (enable|disable,search)
    #   _rc_report true|false
    #   _rc_found first|all
    #   _rc_maybe all|none
    #   _rc_notfound enable|disable
    local def=""
    case "$DI_UNAME_MACHINE" in
        # these have dmi data
        i?86|x86_64|aarch64) def=${DI_DEFAULT_POLICY};;
        *) def=${DI_DEFAULT_POLICY_NO_DMI};;
    esac
    local policy="$1"
    local _def_mode="" _def_report="" _def_found="" _def_maybe=""
    local _def_notfound=""
    if [ $# -eq 1 ] || [ "$2" != "-" ]; then
        def=${2:-${def}}
        parse_def_policy "$def" -
    fi

    local mode="" report="" found="" maybe="" notfound=""
    local oifs="$IFS" tok="" val=""
    IFS=","; set -- $policy; IFS="$oifs"
    for tok in "$@"; do
        val=${tok#*=}
        case "$tok" in
            report) report=true;;
            $DI_ENABLED|$DI_DISABLED|search) mode=$tok;;
            found=all|found=first) found=$val;;
            maybe=all|maybe=none) maybe=$val;;
            notfound=$DI_ENABLED|notfound=$DI_DISABLED) notfound=$val;;
            found=*)
               parse_warn found "$val" "${_def_found}"
               found=${_def_found};;
            maybe=*)
               parse_warn maybe "$val" "${_def_maybe}"
               maybe=${_def_maybe};;
            notfound=*)
               parse_warn notfound "$val" "${_def_notfound}"
               notfound=${_def_notfound};;
        esac
    done
    report=${report:-${_def_report:-false}}
    _rc_report=${report}
    _rc_mode=${mode:-${_def_mode}}
    _rc_found=${found:-${_def_found}}
    _rc_maybe=${maybe:-${_def_maybe}}
    _rc_notfound=${notfound:-${_def_notfound}}
}

read_config() {
    local config=${PATH_DI_CONFIG}
    local _rc_dsname="" _rc_policy="" ret=""
    if [ -f "$config" ]; then
        _read_config < "$config"
        ret=$?
    elif [ -e "$config" ]; then
        error "$config exists but is not a file!"
        ret=1
    fi
    local tok="" key="" val=""
    for tok in ${DI_KERNEL_CMDLINE}; do
        key=${tok%%=*}
        val=${tok#*=}
        case "$key" in
            ci.ds) _rc_dsname="$val";;
            ci.datasource) _rc_dsname="$val";;
            ci.di.policy) _rc_policy="$val";;
        esac
    done

    local _rc_mode _rc_report _rc_found _rc_maybe _rc_notfound
    parse_policy "${_rc_policy}"
    debug 1 "policy loaded: mode=${_rc_mode} report=${_rc_report}" \
            "found=${_rc_found} maybe=${_rc_maybe} notfound=${_rc_notfound}"
    DI_MODE=${_rc_mode}
    DI_REPORT=${_rc_report}
    DI_ON_FOUND=${_rc_found}
    DI_ON_MAYBE=${_rc_maybe}
    DI_ON_NOTFOUND=${_rc_notfound}

    DI_DSNAME="${_rc_dsname}"
    return $ret
}


manual_clean_and_existing() {
    [ -f "${PATH_VAR_LIB_CLOUD}/instance/manual-clean" ]
}

main() {
    local dscheck="" ret_dis=1 ret_en=0
    collect_info

    if [ ! -e "$PATH_RUN_CI_CFG" ]; then
        # the first time the generator is run.
        _print_info >> "$DI_LOG"
    fi

    case "$DI_MODE" in
        $DI_DISABLED)
            debug 1 "mode=$DI_DISABLED. returning $ret_dis"
            return $ret_dis
            ;;
        $DI_ENABLED)
            debug 1 "mode=$DI_ENABLED. returning $ret_en"
            return $ret_en;;
        search) :;;
    esac

    if [ -n "${DI_DSNAME}" ]; then
        debug 1 "datasource '$DI_DSNAME' specified."
        found "$DI_DSNAME"
        return
    fi

    if manual_clean_and_existing; then
        debug 1 "manual_cache_clean enabled. Not writing datasource_list."
        write_result "# manual_cache_clean."
        return
    fi

    # if there is only a single entry in $DI_DSLIST
    set -- $DI_DSLIST
    if [ $# -eq 1 ] || [ $# -eq 2 -a "$2" = "None" ] ; then
        debug 1 "single entry in datasource_list ($DI_DSLIST) use that."
        found "$@"
        return
    fi

    local found="" ret="" ds="" maybe=""
    for ds in ${DI_DSLIST}; do
        dscheck_fn="dscheck_${ds}"
        debug 2 "Checking for datasource '$ds' via '$dscheck_fn'"
        if ! type "$dscheck_fn" >/dev/null 2>&1; then
            warn "No check method '$dscheck_fn' for datasource '$ds'"
            continue
        fi
        $dscheck_fn
        ret="$?"
        case "$ret" in
            $DS_FOUND)
                debug 1 "check for '$ds' returned found";
                found="${found} $ds";;
            $DS_MAYBE)
                debug 1 "check for $ds returned maybe";
                maybe="${maybe} $ds";;
            *) debug 2 "check for $ds returned not-found[$ret]";;
        esac
    done

    debug 2 "found=$found maybe=$maybe"
    set -- $found
    if [ $# -ne 0 ]; then
        if [ $# -eq 1 ]; then
            debug 1 "Found single datasource: $1"
        else
            # found=all
            debug 1 "Found $# datasources found=${DI_ON_FOUND}: $*"
            if [ "${DI_ON_FOUND}" = "first" ]; then
                set -- "$1"
            fi
        fi
        found "$@"
        return
    fi

    set -- $maybe
    if [ $# -ne 0 -a "${DI_ON_MAYBE}" != "none" ]; then
        debug 1 "$# datasources returned maybe: $*"
        found "$@"
        return
    fi

    case "$DI_ON_NOTFOUND" in
        $DI_DISABLED)
            debug 1 "No result. notfound=$DI_DISABLED. returning $ret_dis."
            return $ret_dis
            ;;
        $DI_ENABLED)
            debug 1 "notfound=$DI_ENABLED. returning $ret_en"
            return $ret_en;;
    esac

    error "Unexpected result"
    return 3
}

noop() {
    :
}

case "${DI_MAIN}" in
    main|print_info|noop) "${DI_MAIN}" "$@";;
    *) error "unexpected value for DI_MAIN"; exit 1;;
esac

# vi: syntax=sh ts=4 expandtab