#! /bin/bash
# No, we can not deal with sh alone.

set -e
set -u
# ERR traps should be inherited from functions too. (And command
# substitutions and subshells and whatnot, but for us the function is
# the important part here)
set -E

# websync script for Debian
# Based losely on the old websync written by an
# unknown number of different people over the years and ftpsync.
#
# Copyright (C) 2008,2009 Joerg Jaspert <joerg@debian.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; version 2.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

# In case the admin somehow wants to have this script located someplace else,
# he can set BASEDIR, and we will take that. If it is unset we take ${HOME}
# How the admin sets this isn't our place to deal with. One could use a wrapper
# for that. Or pam_env. Or whatever fits in the local setup. :)
BASEDIR=${BASEDIR:-"${HOME}"}

# Script version. DO NOT CHANGE, *unless* you change the master copy maintained
# by Joerg Jaspert and the Debian mirroradm group.
# This is used to track which mirror is using which script version.
VERSION="0815"

# Source our common functions
. "${BASEDIR}/etc/common"

########################################################################
########################################################################
## functions                                                          ##
########################################################################
########################################################################
# All the stuff we want to do when we exit, no matter where
cleanup() {
    trap - ERR TERM HUP INT QUIT EXIT
    # all done. Mail the log, exit.
    log "Mirrorsync done";
    if [ -n "${MAILTO}" ]; then
        # In case rsync had something on stderr
        if [ -s "${LOGDIR}/rsync-${NAME}.error" ]; then
            mail -e -s "[${PROGRAM}@$(hostname -s)] ($$) rsync ERROR on $(date +"%Y.%m.%d-%H:%M:%S")" ${MAILTO} < "${LOGDIR}/rsync-${NAME}.error"
        fi
        if [ "x${ERRORSONLY}x" = "xfalsex" ]; then
            # And the normal log
            MAILFILES="${LOG}"
            if [ "x${FULLLOGS}x" = "xtruex" ]; then
                # Someone wants full logs including rsync
                MAILFILES="${MAILFILES} ${LOGDIR}/rsync-${NAME}.log"
            fi
            cat ${MAILFILES} | mail -e -s "[${PROGRAM}@$(hostname -s)] web sync finished on $(date +"%Y.%m.%d-%H:%M:%S")" ${MAILTO}
        fi
    fi

    savelog "${LOGDIR}/rsync-${NAME}.log"
    savelog "${LOGDIR}/rsync-${NAME}.error"
    savelog "$LOG" > /dev/null

    rm -f "${LOCK}"
}


# Check rsyncs return value
check_rsync() {

    ret=$1
    msg=$2

    # 24 - vanished source files. Ignored, that should be the target of $UPDATEREQUIRED
    # and us re-running. If it's not, uplink is broken anyways.
    case "${ret}" in
        0) return 0;;
        24) return 0;;
        23) return 2;;
        30) return 2;;
        *)
            error "ERROR: ${msg}"
            return 1
            ;;
    esac
}

########################################################################
########################################################################

# As what are we called?
NAME="`basename $0`"

# Now source the config.
. "${BASEDIR}/etc/${NAME}.conf"

########################################################################
# Config options go here. Feel free to overwrite them in the config    #
# file if you need to.                                                 #
# On debian.org machines the defaults should be ok.                    #
########################################################################

########################################################################
# There should be nothing to edit here, use the config file            #
########################################################################
MIRRORNAME=${MIRRORNAME:-`hostname -f`}
# Where to put logfiles in
LOGDIR=${LOGDIR:-"${BASEDIR}/log"}
# Our own logfile
LOG=${LOG:-"${LOGDIR}/${NAME}.log"}

# Where should we put all the mirrored files?
TO=${TO:-"/org/www.debian.org/www"}

# used by log() and error()
PROGRAM=${PROGRAM:-"${NAME}-$(hostname -s)"}

# Where to send mails about mirroring to?
if [ "x$(hostname -d)x" != "xdebian.orgx" ]; then
    # We are not on a debian.org host
    MAILTO=${MAILTO:-"root"}
else
    # Yay, on a .debian.org host
    MAILTO=${MAILTO:-"mirrorlogs@debian.org"}
fi
# Want errors only or every log?
ERRORSONLY=${ERRORSONLY:-"true"}
# Want full logs, ie. including the rsync one?
FULLLOGS=${FULLLOGS:-"false"}

# How many logfiles to keep
LOGROTATE=${LOGROTATE:-14}

# Our lockfile
LOCK=${LOCK:-"${TO}/Website-Update-in-Progress-${MIRRORNAME}"}
# Do we need another rsync run?
UPDATEREQUIRED="${TO}/Website-Update-Required-${MIRRORNAME}"
# Trace file for mirror stats and checks (make sure we get full hostname)
TRACE=${TRACE:-".project/trace/${MIRRORNAME}"}

# rsync program
RSYNC=${RSYNC:-rsync}
# Rsync filter rules. Used to protect various files we always want to keep, even if we otherwise delete
# excluded files
RSYNC_FILTER=${RSYNC_FILTER:-"--filter=protect_Website-Update-in-Progress-${MIRRORNAME} --filter=protect_${TRACE} --filter=protect_Website-Update-Required-${MIRRORNAME}"}
# Default rsync options for *every* rsync call
RSYNC_OPTIONS=${RSYNC_OPTIONS:-"-prltvHSB8192 --timeout 3600 --stats ${RSYNC_FILTER}"}
RSYNC_OPTIONS2=${RSYNC_OPTIONS2:-"--max-delete=40000 --delay-updates --delete --delete-after --delete-excluded"}
# Which rsync share to use on our upstream mirror?
RSYNC_PATH=${RSYNC_PATH:-"web.debian.org"}

# our username for the rsync share
RSYNC_USER=${RSYNC_USER:-""}
# the password
RSYNC_PASSWORD=${RSYNC_PASSWORD:-""}

# a possible proxy
RSYNC_PROXY=${RSYNC_PROXY:-""}

# General excludes.
EXCLUDE=${EXCLUDE:-"--exclude ${HOSTNAME}"}

# The temp directory used by rsync --delay-updates is not
# world-readable remotely. Always exclude it to avoid errors.
EXCLUDE="${EXCLUDE} --exclude .~tmp~/"

# And site specific excludes, by default its the sponsor stuff that should be local to all (except templates)
SITE_FILTER=${SITE_FILTER:-"--include sponsor.deb.* --exclude sponsor_img.* --exclude sponsor.html --exclude sponsor.*.html --filter=protect_sponsor_img.* --filter=protect_sponsor.html --filter=protect_sponsor.*.html"}

# Hooks
HOOK1=${HOOK1:-""}
HOOK2=${HOOK2:-""}
HOOK3=${HOOK3:-""}
HOOK4=${HOOK4:-""}

# Are we a hub?
HUB=${HUB:-"false"}

# Some sane defaults
cd "${BASEDIR}"
umask 022

# If we are here for the first time, create the
# destination and the trace directory
mkdir -p "${TO}/.project/trace"

# Used to make sure we will have the archive fully and completly synced before
# we stop, even if we get multiple pushes while this script is running.
# Otherwise we can end up with a half-synced archive:
# - get a push
# - sync, while locked
# - get another push. Of course no extra sync run then happens, we are locked.
# - done. Archive not correctly synced, we don't have all the changes from the second push.
touch "${UPDATEREQUIRED}"

# Check to see if another sync is in progress
if ! ( set -o noclobber; echo "$$" > "${LOCK}") 2> /dev/null; then
    if ! $(kill -0 $(cat ${LOCK}) 2>/dev/null); then
        # Process does either not exist or is not owned by us.
        echo "$$" > "${LOCK}"
    else
        echo "Unable to start rsync, lock file still exists, PID $(cat ${LOCK})"
        exit 1
    fi
fi

trap cleanup EXIT ERR TERM HUP INT QUIT

# Start log by redirecting everything there.
exec >"$LOG" 2>&1 </dev/null

# Look who pushed us and note that in the log.
log "Mirrorsync start"
PUSHFROM="${SSH_CONNECTION%%\ *}"
if [ -n "${PUSHFROM}" ]; then
    log "We got pushed from ${PUSHFROM}"
fi
log "Acquired main lock"

HOOK=(
    HOOKNR=1
    HOOKSCR=${HOOK1}
)
hook $HOOK

# Now, we might want to sync from anonymous too.
# This is that deep in this script so hook1 could, if wanted, change things!
if [ -z ${RSYNC_USER} ]; then
    RSYNCPTH="${RSYNC_HOST}"
else
    RSYNCPTH="${RSYNC_USER}@${RSYNC_HOST}"
fi

# Now do the actual mirroring, and run as long as we have an updaterequired file.
export RSYNC_PASSWORD
export RSYNC_PROXY

while [ -e "${UPDATEREQUIRED}" ]; do
    log "Running mirrorsync, update is required, ${UPDATEREQUIRED} exists"

    rm -f "${UPDATEREQUIRED}"
    log "Syncing: ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS2} ${EXCLUDE} ${SITE_FILTER}  ${RSYNCPTH}::${RSYNC_PATH} ${TO}"

    set +e
    ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS2} ${EXCLUDE} ${SITE_FILTER} \
        ${RSYNCPTH}::${RSYNC_PATH} "${TO}" >"${LOGDIR}/rsync-${NAME}.log" 2>"${LOGDIR}/rsync-${NAME}.error"
    result=$?
    set -e

    log "Back from rsync with returncode ${result}"

    set +e
    check_rsync $result "Sync went wrong, got errorcode ${result}. Logfile: ${LOG}"
    GO=$?
    set -e

    if [ ${GO} -eq 2 ] && [ -e "${UPDATEREQUIRED}" ]; then
        log "We got error ${result} from rsync, but a second push went in hence ignoring this error for now"
    elif [ ${GO} -ne 0 ]; then
        exit 3
    fi

    HOOK=(
        HOOKNR=2
        HOOKSCR=${HOOK2}
    )
    hook $HOOK

done

mkdir -p "${TO}/.project/trace"
LC_ALL=POSIX LANG=POSIX date -u > "${TO}/${TRACE}"
echo "Used websync version: ${VERSION}" >> "${TO}/${TRACE}"
echo "Running on host: $(hostname -f)" >> "${TO}/${TRACE}"

HOOK=(
    HOOKNR=3
    HOOKSCR=${HOOK3}
)
hook $HOOK

if [ x${HUB} = "xtrue" ]; then
    log "Trigger slave mirrors"
    ${BASEDIR}/bin/runmirrors "websync"
    log "Trigger slave done"

    HOOK=(
        HOOKNR=4
        HOOKSCR=${HOOK4}
    )
    hook $HOOK
fi

# All done, rest is done by cleanup hook.