Attachment 1157845 Details for Bug 1331655 – Proposed chrony helper (version 2)

Proposed chrony helper (version 2)

chrony-helper (text/plain), 6.25 KB, created by Miroslav Lichvar on 2016-05-16 11:01:51 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Miroslav Lichvar

Created: 2016-05-16 11:01:51 UTC

Size: 6.25 KB

patch

obsolete

>#!/bin/bash
># This script configures running chronyd to use NTP servers obtained from
># DHCP and _ntp._udp DNS SRV records. Files with servers from DHCP are managed
># externally (e.g. by a dhclient script). Files with servers from DNS SRV
># records are updated here using the dig utility. The script can also list
># and set static sources in the chronyd configuration file.
>
>chronyc=/usr/bin/chronyc
>chrony_conf=/etc/chrony.conf
>chrony_service=chronyd.service
>helper_dir=/var/run/chrony-helper
>added_servers_file=$helper_dir/added_servers
>
>network_sysconfig_file=/etc/sysconfig/network
>dhclient_servers_files=/var/lib/dhclient/chrony.servers.*
>dnssrv_servers_files=$helper_dir/dnssrv@*
>dnssrv_timer_prefix=chrony-dnssrv@
>
>chrony_command() {
>    $chronyc -a -n -m "$1"
>}
>
>is_running() {
>    chrony_command "tracking" &> /dev/null
>}
>
>is_update_needed() {
>    for file in $dhclient_servers_files $dnssrv_servers_files \
>            $added_servers_file; do
>        [ -e "$file" ] && return 0
>    done
>    return 1
>}
>
>update_daemon() {
>    local all_servers_with_args all_servers added_servers
>
>    if ! is_running; then
>        rm -f $added_servers_file
>        return 0
>    fi
>
>    all_servers_with_args=$(
>        cat $dhclient_servers_files $dnssrv_servers_files 2> /dev/null)
>
>    all_servers=$(
>        echo "$all_servers_with_args" |
>            while read server serverargs; do
>                echo "$server"
>            done | sort -u)
>    added_servers=$( (
>        cat $added_servers_file 2> /dev/null
>        echo "$all_servers_with_args" |
>            while read server serverargs; do
>                [ -z "$server" ] && continue
>                chrony_command "add server $server $serverargs" &> /dev/null &&
>                    echo "$server"
>            done) | sort -u)
>
>    comm -23 <(echo -n "$added_servers") <(echo -n "$all_servers") |
>        while read server; do
>            chrony_command "delete $server" &> /dev/null
>        done
>
>    added_servers=$(comm -12 <(echo -n "$added_servers") <(echo -n "$all_servers"))
>
>    [ -n "$added_servers" ] && echo "$added_servers" > $added_servers_file ||
>        rm -f $added_servers_file
>}
>
>get_dnssrv_servers() {
>    local name=$1
>
>    if ! command -v dig &> /dev/null; then
>        echo "Missing dig (DNS lookup utility)" >&2
>        return 1
>    fi
>
>    (
>        . $network_sysconfig_file &> /dev/null
>
>        output=$(dig "$name" srv +short +ndots=2 +search 2> /dev/null)
>        [ $? -ne 0 ] && return 0
>
>        echo "$output" | while read prio weight port target; do
>            server=${target%.}
>            [ -z "$server" ] && continue
>            echo "$server port $port ${NTPSERVERARGS:-iburst}"
>        done
>    )
>}
>
>check_dnssrv_name() {
>    local name=$1
>
>    if [ -z "$name" ]; then
>        echo "No DNS SRV name specified" >&2
>        return 1
>    fi
>
>    if [ "${name:0:9}" != _ntp._udp ]; then
>        echo "DNS SRV name $name doesn't start with _ntp._udp" >&2
>        return 1
>    fi
>}
>
>update_dnssrv_servers() {
>    local name=$1
>    local srv_file=$helper_dir/dnssrv@$name servers
>
>    check_dnssrv_name "$name" || return 1
>
>    servers=$(get_dnssrv_servers "$name")
>    [ -n "$servers" ] && echo "$servers" > "$srv_file" || rm -f "$srv_file"
>}
>
>set_dnssrv_timer() {
>    local state=$1 name=$2
>    local srv_file=$helper_dir/dnssrv@$name servers
>    local timer=$dnssrv_timer_prefix$name.timer
>
>    check_dnssrv_name "$name" || return 1
>
>    if [ "$state" = enable ]; then
>        systemctl enable "$timer"
>        systemctl start "$timer"
>    elif [ "$state" = disable ]; then
>        systemctl stop "$timer"
>        systemctl disable "$timer"
>        rm -f "$srv_file"
>    fi
>}
>
>list_dnssrv_timers() {
>    systemctl --all --full -t timer list-units | grep "^$dnssrv_timer_prefix" | \
>        sed "s|^$dnssrv_timer_prefix$.*$\.timer.*|\1|"
>}
>
>prepare_helper_dir() {
>    mkdir -p $helper_dir
>    exec 100> $helper_dir/lock
>    if ! flock -w 20 100; then
>        echo "Failed to lock $helper_dir" >&2
>        return 1
>    fi
>}
>
>is_source_line() {
>    local pattern="^[ \t]*(server|pool|peer|refclock)[ \t]+[^ \t]+"
>    [[ "$1" =~ $pattern ]]
>}
>
>list_static_sources() {
>    while read line; do
>        is_source_line "$line" && echo "$line"
>    done < $chrony_conf
>}
>
>set_static_sources() {
>    local new_config tmp_conf
>
>    new_config=$(
>        sources=$(
>            while read line; do
>                is_source_line "$line" && echo "$line"
>            done)
>
>        while read line; do
>            if ! is_source_line "$line"; then
>                echo "$line"
>                continue
>            fi
>
>            tmp_sources=$(
>                local removed=0
>
>                echo "$sources" | while read line2; do
>                    [ "$removed" -ne 0 -o "$line" != "$line2" ] && \
>                        echo "$line2" || removed=1
>                done)
>
>            [ "$sources" == "$tmp_sources" ] && continue
>            sources=$tmp_sources
>            echo "$line"
>        done < $chrony_conf
>
>        echo "$sources"
>    )
>
>    tmp_conf=${chrony_conf}.tmp
>
>    cp -a $chrony_conf $tmp_conf &&
>        echo "$new_config" > $tmp_conf &&
>        mv $tmp_conf $chrony_conf || return 1
>
>    systemctl try-restart $chrony_service
>}
>
>print_help() {
>    echo "Usage: $0 COMMAND"
>    echo
>    echo "Commands:"
>    echo "	update-daemon"
>    echo "	update-dnssrv-servers NAME"
>    echo "	enable-dnssrv NAME"
>    echo "	disable-dnssrv NAME"
>    echo "	list-dnssrv"
>    echo "	list-static-sources"
>    echo "	set-static-sources < sources.list"
>    echo "	is-running"
>    echo "	command CHRONYC-COMMAND"
>}
>
>case "$1" in
>    update-daemon|add-dhclient-servers|remove-dhclient-servers)
>        is_update_needed || exit 0
>        prepare_helper_dir && update_daemon
>        ;;
>    update-dnssrv-servers)
>        prepare_helper_dir && update_dnssrv_servers "$2" && update_daemon
>        ;;
>    enable-dnssrv)
>        set_dnssrv_timer enable "$2"
>        ;;
>    disable-dnssrv)
>        set_dnssrv_timer disable "$2" && prepare_helper_dir && update_daemon
>        ;;
>    list-dnssrv)
>        list_dnssrv_timers
>        ;;
>    list-static-sources)
>        list_static_sources
>        ;;
>    set-static-sources)
>        set_static_sources
>        ;;
>    is-running)
>        is_running
>        ;;
>    command|forced-command)
>        chrony_command "$2"
>        ;;
>    *)
>        print_help
>        exit 2
>esac
>
>exit $?

Actions: View

Attachments on bug 1331655: 1156167 | 1157845