Munin contributed plugins

#!/bin/sh

: <<=cut

=head1 NAME

rsnapshot_duration - monitor duration of rsnapshot backups in detail

=head1 APPLICABLE SYSTEMS

Any system with local access to an rsnapshot log file.

=head1 CONFIGURATION

rsnapshot's configuration file (e.g. /etc/rsnapshot.conf) needs to

contain the directive "loglevel 3" in order to write the required

log messages to the log file.

The following configuration represents the plugin's defaults:

  [rsnapshot_duration]

  env.rsnapshot_log_file        /var/log/rsnapshot

  env.rsnapshot_operation_name  beta

  env.rsnapshot_description     Backup Duration

"rsnapshot_description" is used for the title of the graph.

"rsnapshot_operation_name" refers to the interval/retain/level of the

rsnapshot operation to be monitored.  This should be the lowest

executed backup interval (e.g. "daily" or "beta").  In case of the

rsnapshot setting "sync_first 1", it should be "sync".

Multiple rsnapshot log files (with different sets of backup sources)

can be monitored.  Simply create one plugin symlink for each log file

and specify suitable plugin configurations for each symlink name.

=head1 INTERPRETATION

The backup duration for each single "backup" task is calculated based

on the difference of the timestamps in the log file.

=head1 AUTHOR

Lars Kruse <devel@sumpfralle.de>

=head1 LICENSE

SPDX-License-Identifier: GPL-3.0-or-later

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf

=cut

set -eu

. "$MUNIN_LIBDIR/plugins/plugin.sh"

LOG_FILE=${rsnapshot_log_file:-/var/log/rsnapshot.log}

RSNAPSHOT_OPERATION_NAME=${rsnapshot_operation_name:-beta}

RSNAPSHOT_DESCRIPTION=${rsnapshot_description:-Backup Duration}

# retrieve the latest set of log files for a complete backup operation

get_latest_process_log() {

    tac "$LOG_FILE" \

        | awk '

            BEGIN { in_process = 0; }

            / '"$RSNAPSHOT_OPERATION_NAME"': completed[, ]/ { in_process = 1; }

            / '"$RSNAPSHOT_OPERATION_NAME"': started$/ { if (in_process == 1) exit; }

            { if (in_process == 1) print($0); }' \

        | tac

}

# parse rsnapshot log lines

# output format:

#     BACKUP_NAME DURATION_SECONDS [ERROR_MESSAGES]

get_backups_with_duration() {

    get_latest_process_log | while read -r timestamp command details; do

        parsed_timestamp=$(date +%s --date "$(printf '%s' "$timestamp" | tr -d '[]')")

        if [ -n "${backup_name:-}" ] && printf '%s' "$command" | grep -q "/rsnapshot$" && printf '%s' "$details" | grep -q "ERROR:"; then

            backup_errors=$(printf '%s' "$details" | sed 's/^.*ERROR: //')

        elif printf '%s' "$command" | grep -q "/rsync$"; then

            if [ -n "${backup_name:-}" ]; then

                printf '%s\t%d\t%s\n' "$backup_name" "$((parsed_timestamp - backup_start))" "${backup_errors:-}"

            fi

            backup_name=$(printf '%s' "$details" | sed 's#/$##' | sed 's#^.*/##')

            backup_start=$parsed_timestamp

            backup_errors=

        elif printf '%s' "$command" | grep -q "/rm$"; then

            # the backup is finished

            if [ -n "${backup_name:-}" ]; then

                printf '%s\t%d\t%s\n' "$backup_name" "$((parsed_timestamp - backup_start))" "${backup_errors:-}"

            fi

            break

        fi

    done | sort

}

do_autoconf() {

    if [ -e "$LOG_FILE" ]; then

        if [ -r "$LOG_FILE" ]; then

            if command -v "tac" >/dev/null; then

                echo "yes"

            else

                echo "no (executable 'tac' (coreutils) is missing)"

            fi

        else

            echo "no (rsnapshot log file is not readable: $LOG_FILE)"

        fi

    else

        echo "no (rsnapshot log file missing: $LOG_FILE)"

    fi

    exit 0

}

get_backup_fieldname() {

    local backup_name="$1"

    clean_fieldname "backup_${backup_name}"

}

print_backup_details() {

    local backup_name="$1"

    local backup_duration="$2"

    local backup_messages="$3"

    local fieldname

    fieldname=$(get_backup_fieldname "$backup_name")

    printf '%s.value %s\n' "$fieldname" "$backup_duration"

    if [ -n "$backup_messages" ]; then

        printf '%s.extinfo %s\n' "$fieldname" "$backup_messages"

    fi

}

do_config() {

    local do_emit_values="${1:-0}"

    echo "graph_title rsnapshot - $RSNAPSHOT_DESCRIPTION"

    echo 'graph_vlabel Duration of backup in minutes'

    echo 'graph_category backup'

    echo 'graph_scale no'

    get_backups_with_duration | while read -r name duration messages; do

        fieldname=$(clean_fieldname "backup_$name")

        printf '%s.label %s\n' "$fieldname" "$name"

        printf '%s.draw %s\n' "$fieldname" "AREASTACK"

        # The duration is stored as an SI unit (seconds).

        # The visualization as the number of minutes should be suitable for most backups.

        printf '%s.cdef %s,60,/\n' "$fieldname" "$fieldname"

        if [ "$do_emit_values" = "1" ]; then

            print_backup_details "$name" "$duration" "$messages"

        fi

    done

}

do_fetch() {

    get_backups_with_duration | while read -r name duration messages; do

        print_backup_details "$name" "$duration" "$messages"

    done

}

case ${1:-} in

    autoconf)

        do_autoconf

        ;;

    config)

        do_config "${MUNIN_CAP_DIRTYCONFIG:-0}"

        ;;

    "")

        do_fetch

        ;;

    *)

        echo >&2 "Unknown command: $1"

        exit 1

        ;;

esac