Release multi-platform docker containers

docker/Dockerfile.release

@@ -0,0 +1,20 @@
+FROM --platform=$BUILDPLATFORM alpine:latest as helper
+
+ARG VERSION
+ARG TARGETOS
+ARG TARGETARCH
+
+# add release binary for the appropriate platform
+COPY restic_${VERSION}_${TARGETOS}_${TARGETARCH}.bz2 /
+RUN apk add --update --no-cache bzip2
+RUN set -e && \
+        bzcat restic_${VERSION}_${TARGETOS}_${TARGETARCH}.bz2 > restic && \
+        chmod +x restic
+
+
+FROM alpine:latest
+
+COPY --from=helper /restic /usr/bin
+RUN apk add --update --no-cache ca-certificates fuse openssh-client tzdata jq
+
+ENTRYPOINT ["/usr/bin/restic"]