zsync/bashclub-zsync/usr/bin/bashclub-zsync

#!/bin/bash
#
# bashclub zfs replication script
# Author: (C) 2023 Thorsten Spille <thorsten@spille-edv.de>

PATH="/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin"

prog="$(basename $0)"
zfs=$(which zfs)
ssh=$(which ssh)
grep=$(which grep)
debug=

#### default config file, can be changed with parameter -c
conf=/etc/bashclub/zsync.conf

#### default values in config file
# replication target on local machine 
target=pool/dataset

# ssh address of remote machine
source=user@host

# ssh port of remote machine
sshport=22

# zfs user parameter to identify filesystems/volumes to replicate
tag=bashclub:zsync

# pipe separated list of snapshot name filters
snapshot_filter="hourly|daily|weekly|monthly"

# minimum count of snapshots per filter to keep
min_keep=3

usage() {
	cat >&2 <<-EOF
	usage: $prog [-h] [-d] [-c CONFIG]
	  creates a mirrored replication of configured zfs filesystems / volumes
    -c CONFIG    Configuration file for this script
    -d           Debug mode
  ---------------------------------------------------------------------------
    (C) 2023     by Spille IT Solutions for bashclub (github.com/bashclub)
                 Author: Thorsten Spille <thorsten@spille-edv.de>
  ---------------------------------------------------------------------------
	EOF
	exit $1
}

while getopts "hdc:" opt; do
  case $opt in
    h) usage 0 ;;
    c) conf=$OPTARG ;;
    d) debug=-v ;;
    *) usage 1 ;;
  esac
done
shift $((OPTIND-1))

function log() {
    echo -e "$(date +'%b %d %T') $1"
}

# load config file
if [ -f $conf ]; then
    log "Reading configuration $conf"
    source $conf
else
    mkdir -p $(dirname $conf)
    cat << EOF > $conf
target=$target
source=$source
sshport=$sshport
tag=$tag
snapshot_filter="$snapshot_filter"
min_keep=$min_keep
EOF
    log "Initial config file created. Please adjust and restart script. Exiting..."
    usage 0
fi

if [[ $source == "" ]]; then
    log "source is empty, switching to local mode."
    ssh=
    sshport=
    log "Configuration:\n\ttarget=$target\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\n"
else
    sshport=-p$sshport
    log "Configuration:\n\ttarget=$target\n\tsource=$source\n\tsshport=$sshport\n\ttag=$tag\n\tsnapshot_filter=$snapshot_filter\n\tmin_keep=$min_keep\n"
fi

local_os_id=$($grep -E "^ID=" /etc/os-release | cut -d'=' -f2)
remote_os_id=$($ssh $source $sshport "grep -E \"^ID=\" /etc/os-release | cut -d'=' -f2")

if [[ $local_os_id == "freebsd" ]]; then
    local_aes=$($grep -o AES /var/run/dmesg.boot | uniq)
else
    local_aes=$($grep -m1 -o aes /proc/cpuinfo | uniq)
fi

if [[ $remote_os_id == "freebsd" ]]; then
    remote_aes=$($ssh $source $sshport "grep -o AES /var/run/dmesg.boot | uniq")
else
    remote_aes=$($ssh $source $sshport "grep -m1 -o aes /proc/cpuinfo | uniq")
fi

if [[ $local_aes == "aes" ]] && [[ $remote_aes == "aes" ]]; then
    if [[ $debug == "-v" ]]; then log "[DEBUG] Switching to cipher aes256-gcm@openssh.com"; fi
    sshcipher=-caes256-gcm@openssh.com
else
    if [[ $debug == "-v" ]]; then log "[DEBUG] Using default cipher chacha20-poly1305@openssh.com"; fi
    sshcipher=-cchacha20-poly1305@openssh.com
fi

include_list="Included datasets:\n"
exclude_list="Excluded datasets:\n"
IFS=$'\n'
for zvol in $($ssh $sshcipher $sshport $source "zfs get -H -o name,value,source -t filesystem,volume $tag"); do
    name=$(echo $zvol | cut -f1)
    if [[ "$(echo $zvol | cut -f2)" == "subvols" ]] && [[ $(echo $zvol | $grep -vE "local|received") ]]; then
        include_list="${include_list}\t${name}\n"
        syncvols=("${syncvols[@]}" "$name")
    elif [[ "$(echo $zvol | cut -f2)" == "all" ]] && [[ $(echo $zvol | $grep -v received) ]];then
        include_list="${include_list}\t${name}\n"
        syncvols=("${syncvols[@]}" "$name")
    else
        exclude_list="${exclude_list}\t${name}\n"
    fi
done
log "$include_list"
log "$exclude_list"


for name in "${syncvols[@]}"; do
    log "Replicate $name"
    if [[ $($ssh $sshcipher $sshport $source zfs get type -o value -H $name) == "filesystem" ]]; then
        mp=-xmountpoint
        cm=-xcanmount
    fi

    if [[ $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name 2>/dev/null | grep -E \"$snapshot_filter\" | wc -l | tr -d ' '") -gt 0 ]]; then
        IFS=$' '
        if [ $($zfs list -H $target/$name > /dev/null 2>&1 ; echo $?) -gt 0 ]; then
            if [[ $debug == "-v" ]]; then log "[DEBUG] $target/$name does not exist"; fi
            prefix=""
            for part in $(echo $target/$(echo $name | cut -d'/' -f1) | sed "s/\// /g"); do
                if [ $($zfs list $prefix$part > /dev/null 2>&1 ; echo $?) -gt 0 ]; then
                    if [[ $debug == "-v" ]]; then log "[DEBUG] $prefix$part does not exist"; fi
                    log "Creating $prefix$part"
                    if [[ $prefix/$part == $target ]]; then
                        if [[ $debug == "-v" ]]; then log "[DEBUG] Disabling com.sun:auto-snapshot on $prefix$part"; fi
                        autosnap=-ocom.sun:auto-snapshot=false
                    fi
                    $zfs create $autosnap -p $prefix$part
                else
                    if [[ $prefix/$part == $target ]] && [[ $(zfs get -H -o value,source com.sun:auto-snapshot $prefix/$part) != "false local" ]]; then
                        if [[ $debug == "-v" ]]; then log "[DEBUG] Disabling com.sun:auto-snapshot on $prefix$part"; fi
                        $zfs set com.sun:auto-snapshot=false $prefix/$part
                    fi
                fi
                prefix="$prefix$part/"
            done

            if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start initial replication"; fi
            IFS=$'\n'
            for snap in $($ssh $sshcipher $sshport $source "zfs list -H -t snapshot -o name -S creation $name | grep -E \"$snapshot_filter\" | tail -1"); do
                log "Start initial replication: $snap => $target/$(echo $name | cut -d'/' -f1)"
                $ssh $ssh_ipher $sshport $source "zfs send -w -p $debug $snap" | $zfs receive $mp $cm -x $tag -x com.sun:auto-snapshot $debug -dF $target/$(echo $name | cut -d'/' -f1)
            done
        fi

        if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start incremental replication"; fi
        guid=$($zfs list -H -o guid -s creation -t snapshot $target/$name | tail -1)
        last=$($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -t snapshot $name | grep $guid | tail -1 | cut -f1")
        IFS=$'\n'
        for snap in $($ssh $sshcipher $sshport $source "zfs list -H -o name,guid -s creation -t snapshot $name | grep -E \"$snapshot_filter\" | grep --after-context=200 $guid | grep -v $guid | cut -f1-2"); do
            log "Replicating delta of $last => $snap to $target/$name"
            $ssh $sshcipher $sshport $source "zfs send -w $debug -i $last $snap" | zfs receive $mp $cm -x $tag -x com.sun:auto-snapshot -F $debug $target/$name
            last=$snap
        done

        if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Start deletion of old snapshots"; fi
        filter=$(echo -e $snapshot_filter | sed "s/|/\n/g")
        IFS=$'\n'
        for interval in $filter ; do
            if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Checking interval $interval"; fi
            guid=$($ssh $sshcipher $sshport $source "zfs list -H -o guid,name -S creation -t snapshot $name | grep $interval | cut -f1 | tail -1")
            if [[ "$(echo -e "$guid" | sed 's/\n//g')" != "" ]]; then
                snaps_to_delete=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep $interval | $grep --after-context=200 $guid | $grep -v $guid | cut -f1)
                snap_count=$($zfs list -H -o name,guid -S creation -t snapshot $target/$name | $grep $interval | wc -l | tr -d ' ')

                for snap in $snaps_to_delete; do
                    if [[ $snap_count -gt $min_keep ]]; then
                        log "Deleting $snap"
                        if [[ $debug == "-v" ]]; then log "[DEBUG] $name - snap_count=$snap_count, min_keep=$min_keep"; fi
                        $zfs destroy $debug $snap
                        snap_count=$(expr $snap_count - 1)
                    else
                        if [[ $debug == "-v" ]]; then log "[DEBUG] $name - Skipping deletion of $snap. snap_count=$snap_count, min_keep=$min_keep"; fi
                    fi
                done
            fi
        done
    else
        if [[ $debug == "-v" ]]; then log "[DEBUG] $name - No snapshots found with filter $snapshot_filter"; fi
    fi
done