docker-volume-backup/src/backup.sh

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#!/bin/sh
# Copyright 2021 - Offen Authors <hioffen@posteo.de>
# SPDX-License-Identifier: MPL-2.0
# Portions of this file are taken from github.com/futurice/docker-volume-backup
# See NOTICE for information about authors and licensing.
source env.sh
function info {
echo -e "\n[INFO] $1\n"
}
info "Preparing backup"
DOCKER_SOCK="/var/run/docker.sock"
if [ -S "$DOCKER_SOCK" ]; then
TEMPFILE="$(mktemp)"
docker ps -q \
--filter "label=docker-volume-backup.stop-during-backup=$BACKUP_STOP_CONTAINER_LABEL" \
> "$TEMPFILE"
CONTAINERS_TO_STOP="$(cat $TEMPFILE | tr '\n' ' ')"
CONTAINERS_TO_STOP_TOTAL="$(cat $TEMPFILE | wc -l)"
CONTAINERS_TOTAL="$(docker ps -q | wc -l)"
rm "$TEMPFILE"
echo "$CONTAINERS_TOTAL containers running on host in total."
echo "$CONTAINERS_TO_STOP_TOTAL containers marked to be stopped during backup."
else
CONTAINERS_TO_STOP_TOTAL="0"
CONTAINERS_TOTAL="0"
echo "Cannot access \"$DOCKER_SOCK\", won't look for containers to stop."
fi
if [ "$CONTAINERS_TO_STOP_TOTAL" != "0" ]; then
info "Stopping containers"
docker stop $CONTAINERS_TO_STOP
fi
info "Creating backup"
BACKUP_FILENAME="$(date +"$BACKUP_FILENAME")"
tar -czvf "$BACKUP_FILENAME" $BACKUP_SOURCES # allow the var to expand, in case we have multiple sources
if [ ! -z "$GPG_PASSPHRASE" ]; then
info "Encrypting backup"
gpg --symmetric --cipher-algo aes256 --batch --passphrase "$GPG_PASSPHRASE" \
-o "${BACKUP_FILENAME}.gpg" $BACKUP_FILENAME
rm $BACKUP_FILENAME
BACKUP_FILENAME="${BACKUP_FILENAME}.gpg"
fi
if [ "$CONTAINERS_TO_STOP_TOTAL" != "0" ]; then
info "Starting containers/services back up"
# The container might be part of a stack when running in swarm mode, so
# its parent service needs to be restarted instead once backup is finished.
SERVICES_REQUIRING_UPDATE=""
for CONTAINER_ID in $CONTAINERS_TO_STOP; do
SWARM_SERVICE_NAME=$(
docker inspect \
--format "{{ index .Config.Labels \"com.docker.swarm.service.name\" }}" \
$CONTAINER_ID
)
if [ -z "$SWARM_SERVICE_NAME" ]; then
echo "Restarting $(docker start $CONTAINER_ID)"
else
echo "Removing $(docker rm $CONTAINER_ID)"
# Multiple containers might belong to the same service, so they will
# be restarted only after all names are known.
SERVICES_REQUIRING_UPDATE="${SERVICES_REQUIRING_UPDATE} ${SWARM_SERVICE_NAME}"
fi
done
if [ -n "$SERVICES_REQUIRING_UPDATE" ]; then
for SERVICE_NAME in $(echo -n "$SERVICES_REQUIRING_UPDATE" | tr ' ' '\n' | sort -u); do
docker service update --force $SERVICE_NAME
done
fi
fi
if [ ! -z "$AWS_S3_BUCKET_NAME" ]; then
info "Uploading backup to remote storage"
echo "Will upload to bucket \"$AWS_S3_BUCKET_NAME\"."
mc cp $MC_GLOBAL_OPTIONS "$BACKUP_FILENAME" "backup-target/$AWS_S3_BUCKET_NAME"
echo "Upload finished."
fi
if [ -f "$BACKUP_FILENAME" ]; then
info "Cleaning up"
rm -vf "$BACKUP_FILENAME"
fi
info "Backup finished"
echo "Will wait for next scheduled backup."
if [ ! -z "$BACKUP_RETENTION_DAYS" ]; then
info "Pruning old backups"
echo "Sleeping ${BACKUP_PRUNING_LEEWAY} before checking eligibility."
sleep "$BACKUP_PRUNING_LEEWAY"
bucket=$AWS_S3_BUCKET_NAME
rule_applies_to=$(
mc rm $MC_GLOBAL_OPTIONS --fake --recursive -force \
--older-than "${BACKUP_RETENTION_DAYS}d" \
"backup-target/$bucket" \
| wc -l
)
if [ "$rule_applies_to" == "0" ]; then
echo "No backups found older than the configured retention period of $BACKUP_RETENTION_DAYS days."
echo "Doing nothing."
exit 0
fi
total=$(mc ls $MC_GLOBAL_OPTIONS "backup-target/$bucket" | wc -l)
if [ "$rule_applies_to" == "$total" ]; then
echo "Using a retention of ${BACKUP_RETENTION_DAYS} days would prune all currently existing backups, will not continue."
echo "If this is what you want, please remove files manually instead of using this script."
exit 1
fi
mc rm $MC_GLOBAL_OPTIONS \
--recursive -force \
--older-than "${BACKUP_RETENTION_DAYS}d" "backup-target/$bucket"
echo "Successfully pruned ${rule_applies_to} backups older than ${BACKUP_RETENTION_DAYS} days."
fi