#! /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

# ftpsync script for Debian
# Based losely on a number of existing scripts, written by an
# unknown number of different people over the years.
#
# Copyright (C) 2008,2009,2010,2011 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="80387"

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

########################################################################
########################################################################
## functions                                                          ##
########################################################################
########################################################################
# We want to be able to get told what kind of sync we should do. This
# might be anything, from the archive to sync, the stage to do, etc. A
# list of currently understood and valid options is below. Multiple
# options are seperated by space. All the words have to have the word
# sync: in front or nothing will get used!
#
# Option        Behaviour
# stage1		 Only do stage1 sync
# stage2		 Only do stage2 sync
# all			 Do a complete sync
# mhop           Do a mhop sync, usually additionally to stage1
# archive:foo    Sync archive foo (if config for foo is available)
# callback       Call back when done (needs proper ssh setup for this to
#                work). It will always use the "command" callback:$HOSTNAME
#                where $HOSTNAME is the one defined below/in config and
#                will happen before slave mirrors are triggered.
#
# So to get us to sync all of the archive behind bpo and call back when
# we are done, a trigger command of
# "ssh $USER@$HOST sync:all sync:archive:bpo sync:callback" will do the
# trick.
check_commandline() {
    while [ $# -gt 0 ]; do
        case "$1" in
            sync:stage1)
                SYNCSTAGE1="true"
                SYNCALL="false"
                ;;
            sync:stage2)
                SYNCSTAGE2="true"
                SYNCALL="false"
                ;;
            sync:callback)
                SYNCCALLBACK="true"
                ;;
            sync:archive:*)
                ARCHIVE=${1##sync:archive:}
                # We do not like / or . in the remotely supplied archive name.
                ARCHIVE=${ARCHIVE//\/}
                ARCHIVE=${ARCHIVE//.}
                ;;
            sync:all)
                SYNCALL="true"
                ;;
            sync:mhop)
                SYNCMHOP="true"
                ;;
            *)
                echo "Unknown option ${1} ignored"
                ;;
        esac
        shift  # Check next set of parameters.
    done
}

# 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";

    # Lets get a statistical value
    SPEED="unknown"
    if [ -f "${LOGDIR}/rsync-${NAME}.log" ]; then
        SPEED=$(
            SPEEDLINE=$(egrep '[0-9.]+ bytes/sec' "${LOGDIR}/rsync-${NAME}.log")
            set "nothing" ${SPEEDLINE}
            echo ${8:-""}
        )
        if [ -n "${SPEED}" ]; then
            SPEED=${SPEED%%.*}
            SPEED=$(( $SPEED / 1024 ))
        fi
    fi
    log "Rsync transfer speed: ${SPEED} KB/s"

    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)] archive 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)"
# The original command line arguments need to be saved!
if [ $# -gt 0 ]; then
    ORIGINAL_COMMAND=$*
else
    ORIGINAL_COMMAND=""
fi

SSH_ORIGINAL_COMMAND=${SSH_ORIGINAL_COMMAND:-""}
# Now, check if we got told about stuff via ssh
if [ -n "${SSH_ORIGINAL_COMMAND}" ]; then
    # We deliberately add "nothing" and ignore it right again, to avoid
    # people from outside putting some set options in the first place,
    # making us parse them...
    set "nothing" "${SSH_ORIGINAL_COMMAND}"
    shift
    # Yes, unqouted $* here. Or the function will only see it as one
    # parameter, which doesnt help the case in it.
    check_commandline $*
fi

# Now, we can locally override all the above variables by just putting
# them into the .ssh/authorized_keys file forced command.
if [ -n "${ORIGINAL_COMMAND}" ]; then
    set ${ORIGINAL_COMMAND}
    check_commandline $*
fi

# If we have been told to do stuff for a different archive than default,
# set the name accordingly.
ARCHIVE=${ARCHIVE:-""}
if [ -n "${ARCHIVE}" ]; then
    NAME="${NAME}-${ARCHIVE}"
fi

# Now source the config for the archive we run on.
# (Yes, people can also overwrite the options above in the config file
# if they want to)
if [ -f "${BASEDIR}/etc/${NAME}.conf" ]; then
    . "${BASEDIR}/etc/${NAME}.conf"
else
    echo "Nono, you can't tell us about random archives. Bad boy!"
    exit 1
fi

########################################################################
# 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.                    #
#                                                                      #
# The following extra variables can be defined in the config file:     #
#                                                                      #
# ARCH_EXCLUDE                                                         #
#  can be used to exclude a complete architecture from                 #
# mirrorring. Use as space seperated list.                             #
# Possible values are:                                                 #
# alpha, amd64, arm, armel, armhf, hppa, hurd-i386, i386, ia64, mips   #
# mipsel, powerpc, s390, s390x, sparc, kfreebsd-i386, kfreebsd-amd64   #
# and source.                                                          #
# eg. ARCH_EXCLUDE="alpha arm armel mipsel mips s390 s390x sparc"      #
#                                                                      #
# An unset value will mirror all architectures                         #
########################################################################

########################################################################
# 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:-"/srv/mirrors/debian/"}

# 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}/Archive-Update-in-Progress-${MIRRORNAME}"}
# timeout for the lockfile, in case we have bash older than v4 (and no /proc)
LOCKTIMEOUT=${LOCKTIMEOUT:-3600}
# Do we need another rsync run?
UPDATEREQUIRED="${TO}/Archive-Update-Required-${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_Archive-Update-in-Progress-${MIRRORNAME} --filter=protect_${TRACE} --filter=protect_Archive-Update-Required-${MIRRORNAME}"}
# limit I/O bandwidth. Value is KBytes per second, unset or 0 is unlimited
RSYNC_BW=${RSYNC_BW:-0}
# Default rsync options for *every* rsync call
RSYNC_OPTIONS=${RSYNC_OPTIONS:-"-prltvHSB8192 --timeout 3600 --stats ${RSYNC_FILTER}"}
# Options we only use in the first pass, where we do not want packages/sources to fly in yet and don't want to delete files
RSYNC_OPTIONS1=${RSYNC_OPTIONS1:-"--exclude Packages* --exclude Sources* --exclude Release* --exclude InRelease --exclude ls-lR*"}
# Options for the second pass, where we do want everything, including deletion of old and now unused files
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:-"debian"}

# Now add the bwlimit option. As default is 0 we always add it, rsync interprets
# 0 as unlimited, so this is safe.
RSYNC_OPTIONS="--bwlimit=${RSYNC_BW} ${RSYNC_OPTIONS}"

# We have no default host to sync from, but will error out if its unset
RSYNC_HOST=${RSYNC_HOST:-""}
# Error out if we have no host to sync from
if [ -z "${RSYNC_HOST}" ]; then
    error "Missing a host to mirror from, please set RSYNC_HOST variable in ${BASEDIR}/etc/${NAME}.conf"
fi

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

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

# Do we sync stage1?
SYNCSTAGE1=${SYNCSTAGE1:-"false"}
# Do we sync stage2?
SYNCSTAGE2=${SYNCSTAGE2:-"false"}
# Do we sync all?
SYNCALL=${SYNCALL:-"true"}
# Do we have a mhop sync?
SYNCMHOP=${SYNCMHOP:-"false"}
# Do we callback?
SYNCCALLBACK=${SYNCCALLBACK:-"false"}
# If we call back we need some more options defined in the config file.
CALLBACKUSER=${CALLBACKUSER:-"archvsync"}
CALLBACKHOST=${CALLBACKHOST:-"none"}
CALLBACKKEY=${CALLBACKKEY:-"none"}

# General excludes. Don't list architecture specific stuff here, use ARCH_EXCLUDE for that!
EXCLUDE=${EXCLUDE:-""}

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

SOURCE_EXCLUDE=${SOURCE_EXCLUDE:-""}
ARCH_EXCLUDE=${ARCH_EXCLUDE:-""}
# Exclude architectures defined in $ARCH_EXCLUDE
for ARCH in ${ARCH_EXCLUDE}; do
    EXCLUDE="${EXCLUDE} --exclude binary-${ARCH}/ --exclude installer-${ARCH}/ --exclude Contents-${ARCH}.gz --exclude Contents-${ARCH}.bz2 --exclude Contents-${ARCH}.diff/ --exclude arch-${ARCH}.files --exclude arch-${ARCH}.list.gz --exclude *_${ARCH}.deb --exclude *_${ARCH}.udeb --exclude *_${ARCH}.changes"
    if [ "${ARCH}" = "source" ]; then
        if [ -z ${SOURCE_EXCLUDE} ]; then
            SOURCE_EXCLUDE=" --exclude source/ --exclude *.tar.gz --exclude *.diff.gz --exclude *.tar.bz2 --exclude *.tar.xz -exclude *.diff.bz2 --exclude *.dsc "
        fi
    fi
done

# Hooks
HOOK1=${HOOK1:-""}
HOOK2=${HOOK2:-""}
HOOK3=${HOOK3:-""}
HOOK4=${HOOK4:-""}
HOOK5=${HOOK5:-""}

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

########################################################################
# Really nothing to see below here. Only code follows.                 #
########################################################################
########################################################################

# 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 "$$" > "${LOCK}") 2> /dev/null; then
    if [ ${BASH_VERSINFO[0]} -gt 3 ] || [ -L /proc/self ]; then
        # We have a recent enough bash version, lets do it the easy way,
        # the lock will contain the right pid, thanks to $BASHPID
        if ! $(kill -0 $(cat ${LOCK}) 2>/dev/null); then
            # Process does either not exist or is not owned by us.
            echo "$$" > "${LOCK}"
        else
            echo "Unable to start rsync, lock file still exists, PID $(cat ${LOCK})"
            exit 1
        fi
    else
        # Old bash, means we dont have the right pid in our lockfile
        # So take a different way - guess if it is still there by comparing its age.
        # Not optimal, but hey.
        stamptime=$(date --reference="${LOCK}" +%s)
        unixtime=$(date +%s)
        difference=$(( $unixtime - $stamptime ))
        if [ ${difference} -ge ${LOCKTIMEOUT} ]; then
            # Took longer than LOCKTIMEOUT minutes? Assume it broke and take the lock
            echo "$$" > "${LOCK}"
        else
            echo "Unable to start rsync, lock file younger than one hour"
            exit 1
        fi
    fi
fi

# When we exit normally we call cleanup on our own. Otherwise we want it called by
# this trap.  (We can not trap on EXIT, because that is called when the main script
# exits. Which also happens when we background the mainroutine, ie. while we still
# run!)
trap cleanup ERR TERM HUP INT QUIT

# Start log by redirecting stdout and stderr there and closing stdin
exec >"$LOG" 2>&1 <&-
log "Mirrorsync start"

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

if [ "xtruex" = "x${SYNCCALLBACK}x" ]; then
    if [ "xnonex" = "x${CALLBACKHOST}x" ] || [ "xnonex" = "x${CALLBACKKEY}x" ]; then
        SYNCCALLBACK="false"
        error "We are asked to call back, but we do not know where to and do not have a key, ignoring callback"
    fi
fi

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"

    # if we want stage1 *or* all
    if [ "xtruex" = "x${SYNCSTAGE1}x" ] || [ "xtruex" = "x${SYNCALL}x" ]; then
        while [ -e "${UPDATEREQUIRED}" ]; do
            rm -f "${UPDATEREQUIRED}"
            log "Running stage1: ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS1} ${EXCLUDE} ${SOURCE_EXCLUDE}  ${RSYNCPTH}::${RSYNC_PATH} ${TO}"

            set +e
            # Step one, sync everything except Packages/Releases
            ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS1} ${EXCLUDE} ${SOURCE_EXCLUDE} \
                ${RSYNCPTH}::${RSYNC_PATH} "${TO}" >"${LOGDIR}/rsync-${NAME}.log" 2>"${LOGDIR}/rsync-${NAME}.error"
            result=$?
            set -e

            log "Back from rsync with returncode ${result}"
        done
    else
        # Fake a good resultcode
        result=0
    fi # Sync stage 1?
    rm -f "${UPDATEREQUIRED}"

    set +e
    check_rsync $result "Sync step 1 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

    # if we want stage2 *or* all
    if [ "xtruex" = "x${SYNCSTAGE2}x" ] || [ "xtruex" = "x${SYNCALL}x" ]; then
        upstream_uip=false
        for aupfile in "${TO}/Archive-Update-in-Progress-"*; do
            case "$aupfile" in
                "${TO}/Archive-Update-in-Progress-*")
                    error "Lock file is missing, this should not happen"
                ;;
                "${LOCK}")
                    :
                ;;
                *)
                    upstream_uip=true
                ;;
            esac
        done

        if $upstream_uip; then
            log "Upstream archive update in progress, skipping stage2 (ignore rsync error below)"
	    result=1
        else
            log "Running stage2: ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS2} ${EXCLUDE} ${SOURCE_EXCLUDE} ${RSYNCPTH}::${RSYNC_PATH} ${TO}"

            set +e
            # We are lucky, it worked. Now do step 2 and sync again, this time including
            # the packages/releases files
            ${RSYNC} ${RSYNC_OPTIONS} ${RSYNC_OPTIONS2} ${EXCLUDE} ${SOURCE_EXCLUDE} \
                ${RSYNCPTH}::${RSYNC_PATH} "${TO}" >>"${LOGDIR}/rsync-${NAME}.log" 2>>"${LOGDIR}/rsync-${NAME}.error"
            result=$?
            set -e

            log "Back from rsync with returncode ${result}"
        fi
    else
        # Fake a good resultcode
        result=0
    fi # Sync stage 2?

    set +e
    check_rsync $result "Sync step 2 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 4
    fi

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

# We only update our tracefile when we had a stage2 or an all sync.
# Otherwise we would update it after stage1 already, which is wrong.
if [ "xtruex" = "x${SYNCSTAGE2}x" ] || [ "xtruex" = "x${SYNCALL}x" ]; then
    if [ -d "$(dirname "${TO}/${TRACE}")" ]; then
        LC_ALL=POSIX LANG=POSIX date -u > "${TO}/${TRACE}"
        echo "Used ftpsync version: ${VERSION}" >> "${TO}/${TRACE}"
        echo "Running on host: $(hostname -f)" >> "${TO}/${TRACE}"
    fi
fi

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

if [ "xtruex" = "x${SYNCCALLBACK}x" ]; then
    set +e
    callback ${CALLBACKUSER} ${CALLBACKHOST} "${CALLBACKKEY}"
    set -e
fi

# Remove the Archive-Update-in-Progress file before we push our downstreams.
rm -f "${LOCK}"

if [ x${HUB} = "xtrue" ]; then
    # Trigger slave mirrors if we had a push for stage2 or all, or if its mhop
    if [ "xtruex" = "x${SYNCSTAGE2}x" ] || [ "xtruex" = "x${SYNCALL}x" ] || [ "xtruex" = "x${SYNCMHOP}x" ]; then
        RUNMIRRORARGS=""
        if [ -n "${ARCHIVE}" ]; then
            # We tell runmirrors about the archive we are running on.
            RUNMIRRORARGS="-a ${ARCHIVE}"
        fi
        # We also tell runmirrors that we are running it from within ftpsync, so it can change
        # the way it works with mhop based on that.
        RUNMIRRORARGS="${RUNMIRRORARGS} -f"

        if [ "xtruex" = "x${SYNCSTAGE1}x" ]; then
            # This is true when we have a mhop sync. A normal multi-stage push sending stage1 will
            # not get to this point.
            # So if that happens, tell runmirrors we are doing mhop
            RUNMIRRORARGS="${RUNMIRRORARGS} -k mhop"
        elif [ "xtruex" = "x${SYNCSTAGE2}x" ]; then
            RUNMIRRORARGS="${RUNMIRRORARGS} -k stage2"
        elif [ "xtruex" = "x${SYNCALL}x" ]; then
            RUNMIRRORARGS="${RUNMIRRORARGS} -k all"
        fi
        log "Trigger slave mirrors using ${RUNMIRRORARGS}"
        ${BASEDIR}/bin/runmirrors ${RUNMIRRORARGS}
        log "Trigger slave done"

        HOOK=(
            HOOKNR=5
            HOOKSCR=${HOOK5}
        )
        hook $HOOK
    fi
fi

# All done, lets call cleanup
cleanup