Add support for bandwith limitation

src/borgwrapper.sh

@@ -87,6 +87,19 @@ borg_exec () {
     ${BORG} "$@"
 }
 
+limit_bw () {
+    if ! [[ -x $(command -v pv) ]]; then
+        >&2 echo "WARNING: BWLIMIT is enabled, but the utility 'pv' is not available. Continuing without bandwith limitation."
+        return 0
+    fi
+
+    export PV_WRAPPER=$(mktemp)
+    chmod +x ${PV_WRAPPER}
+    echo -e '#!/bin/bash\npv -q -L ${BWLIMIT} | "$@"' > ${PV_WRAPPER}
+    export BWLIMIT
+    export BORG_RSH="${PV_WRAPPER} ssh"
+}
+
 pre_backup_cmd () {
     [[ -n ${PRE_BACKUP_CMD} ]] || return 0
     echo "Running pre backup command: ${PRE_BACKUP_CMD[@]}"
@@ -121,6 +134,7 @@ lock_failed () {
 }
 
 exit_clean () {
+    [[ -n ${PV_WRAPPER} ]] && rm -f ${PV_WRAPPER}
     trap - ERR INT TERM
     exit $1
 }
@@ -162,6 +176,10 @@ export BORG_PASSPHRASE
     trap 'error_handler ${LINENO} $?' ERR INT TERM
     set -o errtrace -o pipefail
 
+    if [[ ${BWLIMIT} -gt 0 ]]; then
+        limit_bw
+    fi
+
     if [[ ${MODE} == "init" ]]; then
         borg_init
     elif [[ ${MODE} == "backup" ]]; then

src/config.sh.example

@@ -22,6 +22,10 @@ KEEP_WEEKLY=0
 KEEP_MONTHLY=24
 KEEP_YEARLY=5
 
+# Limit bandwith used when backing up to SSH repositories. Requires the utility `pv`.
+# The unit is bytes per second. 0 means no limit.
+#BWLIMIT=0
+
 # Change this if you need to have multiple borgwrapper instances running
 # using different configs.
 #LOCKFILE="/var/lock/borgwrapper.lock"