README.md

@@ -1,39 +0,0 @@
-# Docker Volume Backup
-
-A simple script which creates tarballs from docker volumes and restores
-them.
-
-## Usage
-
-### Backup a single volume
-
-`./dvbackup.sh backup <volume_name> <path/to/tarball.tar>`
-
-Creates a tarball from the contents of the volume.
-
-### Restore a single volume
-
-`./dvbackup.sh restore <path/to/tarball.tar> <volume_name>`
-
-Restores the tarball into the volume. *This is destructive*, all old
-contents will be removed from the volume. The volume must already exist.
-
-### Backup all named volumes
-
-`./dvbackup.sh backup_all`
-
-Creates backups from all volumes which do not only contain the character
-set `[0-9a-f]`.
-
-This command will output a `<volume_name>.tar` file for every found
-volume in the current working directory.
-
-### Restore volumes
-
-`./dvbackup.sh restore_all [volume.tar...]`
-
-Restores all given tarballs into their respective volumes. The volumes
-must already exist and the operation is *destructive* in the same way
-as the `restore` operation. The default behaviour is to ask before
-continuing, this can be overridden by setting `DVB_I_KNOW_WHAT_I_DO=y`.
-Volumes can be created implicitly by setting `DVB_CREATE_VOLUME=y`.

dvbackup.sh

@@ -1,81 +1,50 @@
-#!/usr/bin/env sh
+#!/usr/bin/env bash
-
-if [ -z "$DOCKER" ]; then
-    DOCKER=docker
-fi
-
-
-echo_and_run() {
-    echo "$@"
-    "$@"
-    return $?
-}
 
 backup() {
+    local volume
+    local target
+    local target_dir
+    local target_name
     volume="$1"
     target="$(realpath "$2")"
     target_dir="$(dirname "$target")"
     target_name="$(basename "$target")"
 
-    test -z "$("$DOCKER" volume ls | grep "$volume")" && { echo "Error: No such volume, aborting" >&2; exit 1; }
+    test -z "$(docker volume ls | grep "$volume")" && { echo "Error: No such volume, aborting" >&2; exit 1; }
     test -z "$target_dir" && { echo "Error: No base folder found for target=$target" >&2; exit 2; }
     test -z "$target_name" && { echo "Error: No target name found for target=$target" >&2; exit 3; }
 
-    echo_and_run "$DOCKER" run --rm \
+    set -x
-        --mount="type=volume,source=$volume,destination=/data,ro=true" \
+    docker run --rm --mount="type=volume,source=$volume,destination=/data,ro=true" --mount="type=bind,source=$target_dir,destination=/data2" busybox /bin/sh -c "tar cvf '/data2/$target_name' /data && chown $(id -u):$(id -g) /data2/$target_name"
-        --mount="type=bind,source=$target_dir,destination=/data2" \
+    set +x
-        busybox /bin/sh -c \
-        "cd /data/ && tar cf '/data2/$target_name' ./* && chown $(id -u):$(id -g) /data2/$target_name"
 }
 
 restore() {
+    local volume
+    local target
+    local target_dir
+    local target_name
     target="$(realpath "$1")"
     target_dir="$(dirname "$target")"
     target_name="$(basename "$target")"
     volume="$2"
 
-    test -z "$("$DOCKER" volume ls | grep "$volume")" && { echo "Error: No such volume, aborting" >&2; exit 1; }
+    test -z "$(docker volume ls | grep "$volume")" && { echo "Error: No such volume, aborting" >&2; exit 1; }
     test -z "$target_dir" && { echo "Error: No base folder found for target=$target" >&2; exit 2; }
     test -z "$target_name" && { echo "Error: No target name found for target=$target" >&2; exit 3; }
 
-    echo_and_run "$DOCKER" run --rm \
+    set -x
-        --mount="type=volume,source=$volume,destination=/data" \
+    docker run --rm --mount="type=volume,source=$volume,destination=/data" --mount="type=bind,source=$target_dir,destination=/data2" busybox /bin/sh -c "rm -rf /data/* && cd / && tar xvf '/data2/$target_name'"
-        --mount="type=bind,source=$target_dir,destination=/data2" \
+    set +x
-        busybox /bin/sh -c \
-        "cd /data/ && rm -rf ./* && tar xf '/data2/$target_name'"
 }
 
-backup_all() {
+main() {
-    "$DOCKER" volume ls \
+    local volumes
-            | awk '!/^[a-z]+ +[0-9a-f]+$/ && (NR>1) {print $2}' \
+    volumes="$(docker volume ls | tail -n+2 | egrep -v '[a-z]+\s+[0-9a-f]+$' | egrep -o '\s.+$' | sed 's/\s//g')"
-            | while read -r volume_name; do
+    while read -r line; do
-        echo "$volume_name -> $volume_name.tar"
+        echo "$line -> $line.tar"
-        backup "$volume_name" "$volume_name.tar"
+        backup "$line" "$line.tar"
-    done
+    done <<< "$volumes"
-}
-
-restore_all() {
-    if [ -z "$DVB_I_KNOW_WHAT_I_DO" ]; then
-        printf "The following operation will delete all data in the volumes to be restored, are you sure [y/N]? "
-        read -r DVB_I_KNOW_WHAT_I_DO
-    fi
-    if echo "$DVB_I_KNOW_WHAT_I_DO" | grep -Eviq 't|true|1|y|yes'; then
-        echo aborting
-        exit 1
-    fi
-    for tarball in "$@"; do
-        volume_name="${tarball%.tar}"
-        echo "$volume_name -> $volume"
-        if ! "$DOCKER" volume inspect "$volume_name" 1>&2 2>/dev/null; then
-            if echo "$DVB_CREATE_VOLUME" | grep -Eiq 't|true|1|y|yes'; then
-                "$DOCKER" volume create "$volume_name"
-            else
-                echo "Error: no such volume $volume_name" >&2
-                exit 4
-            fi
-        fi
-        restore "$tarball" "$volume_name"
-    done
 }
 
 "$@"

test/mock-docker.sh

@@ -1,24 +0,0 @@
-#!/usr/bin/env sh
-
-volume() {
-    if [ "$1" = 'ls' ]; then
-        echo "DRIVER VOLUME NAME"
-        echo "local 00c674e3f3c1587d88c2ebf2f91da5843b9dddb3e8df272898bdfd4e596aef79"
-        echo "local $DOCKER_MOCK_VOLUME"
-        return 0
-    elif [ "$2" = 'inspect' ]; then
-        if [ "$3" = "$DOCKER_MOCK_VOLUME" ]; then
-            return 0
-        else
-            return 1
-        fi
-    fi
-}
-
-
-if [ "$1" = "volume" ]; then
-    "$@"
-else
-    docker "$@"
-fi
-

test/test.sh

@@ -1,23 +0,0 @@
-#!/usr/bin/env sh
-
-
-cd "$(dirname "$0")" || exit 1
-
-VOLUME_NAME="$(dd if=/dev/random bs=6 count=1 | base64)"
-docker volume create "$VOLUME_NAME"
-
-# shellcheck disable=SC2064
-trap "docker volume rm $VOLUME_NAME && rm -f $VOLUME_NAME.tar" EXIT
-
-docker run --rm --volume="$VOLUME_NAME:/data" alpine \
-    sh -c 'echo "test" > /data/a.txt'
-DOCKER=./mock-docker.sh DOCKER_MOCK_VOLUME="$VOLUME_NAME" \
-    ../dvbackup.sh backup_all
-stat "$VOLUME_NAME.tar" || exit 1
-docker run --rm --volume="$VOLUME_NAME:/data" alpine \
-    sh -c 'rm /data/a.txt' || exit 1
-DOCKER=./mock-docker.sh DOCKER_MOCK_VOLUME="$VOLUME_NAME" \
-    ../dvbackup.sh restore_all "$VOLUME_NAME.tar" || exit 1
-docker run --rm --volume="$VOLUME_NAME:/data" alpine \
-    sh -c 'stat /data/a.txt' || exit 1
-exit 0