initial commit

Dockerfile

@@ -0,0 +1,4 @@
+FROM alpine:latest
+
+RUN apk add --no-cache libarchive-tools zstd
+

Makefile

@@ -0,0 +1,11 @@
+image:
+	docker build --pull -t localhost/archiver .
+
+clean:
+	docker rmi localhost/archiver
+
+dump:
+	mkdir -p dumps
+	cd dumps && bash ../dump.sh
+
+.PHONY: image clean

dump.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -e -o pipefail
+
+info() {
+    [ "$#" -gt 0 ] && echo -e "\033[1m>>> $*\033[0m" >&2
+}
+
+readarray -t volumes < <(docker volume ls --format "{{ .Name }}")
+
+for v in "${volumes[@]}"; do
+    info "Dumping \"$v\""
+    docker run --rm -v "$v":/vol:ro localhost/archiver sh -c \
+        "bsdtar -C /vol --numeric-owner -c . | zstdmt -15v" \
+        > "$v".tar.zst
+
+    docker volume inspect "$v" > "$v".json
+done

restore.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -e -o pipefail
+
+info() {
+    [ "$#" -gt 0 ] && echo -e "\033[1m>>> $*\033[0m" >&2
+}
+
+for i in *.json; do
+    [ -f "$i" ] || continue
+    vol_name=${i%.json}
+    archive=$vol_name.tar.zst
+    info "Recovering \"$vol_name\" from \"$archive\""
+
+    label_args=()
+    readarray -t labels < <(jq -r '.[0].Labels | to_entries | .[] | .key + "=" + .value' "$i")
+    for label in "${labels[@]}"; do
+        label_args+=(--label "$label")
+    done
+
+    set -x
+    docker volume create "${label_args[@]}" "$vol_name"
+    docker run --rm -v "$vol_name":/vol -v "$(readlink -f "$archive")":/vol.tar.zst:ro \
+        localhost/archiver bsdtar -C /vol --numeric-owner -xf /vol.tar.zst
+    set +x
+done