Swarm mode check fails on non-standard Info responses

cmd/backup/stop_restart.go

@@ -81,6 +81,16 @@ func awaitContainerCountForService(cli *client.Client, serviceID string, count i
 	}
 }
 
+func isSwarm(c interface {
+	Info(context.Context) (types.Info, error)
+}) (bool, error) {
+	info, err := c.Info(context.Background())
+	if err != nil {
+		return false, errwrap.Wrap(err, "error getting docker info")
+	}
+	return info.Swarm.LocalNodeState != "" && info.Swarm.LocalNodeState != swarm.LocalNodeStateInactive, nil
+}
+
 // stopContainersAndServices stops all Docker containers that are marked as to being
 // stopped during the backup and returns a function that can be called to
 // restart everything that has been stopped.
@@ -89,11 +99,10 @@ func (s *script) stopContainersAndServices() (func() error, error) {
 		return noop, nil
 	}
 
-	dockerInfo, err := s.cli.Info(context.Background())
+	isDockerSwarm, err := isSwarm(s.cli)
 	if err != nil {
-		return noop, errwrap.Wrap(err, "error getting docker info")
+		return noop, errwrap.Wrap(err, "error determining swarm state")
 	}
-	isDockerSwarm := dockerInfo.Swarm.LocalNodeState != "inactive"
 
 	labelValue := s.c.BackupStopDuringBackupLabel
 	if s.c.BackupStopContainerLabel != "" {

test/balena/Dockerfile

@@ -0,0 +1,76 @@
+#syntax=docker/dockerfile:1.2
+
+# BUILDPLATFORM is set by buildkit (DOCKER_BUILDKIT=1)
+# hadolint ignore=DL3029
+FROM --platform=$BUILDPLATFORM debian:bullseye-20211220-slim AS buildroot-base
+
+# hadolint ignore=DL3008
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        bc \
+        build-essential \
+        ca-certificates \
+        cmake \
+        cpio \
+        file \
+        git \
+        locales \
+        python3 \
+        rsync \
+        unzip \
+        wget && \
+    apt-get clean && rm -rf /var/lib/apt/lists/*
+
+# hadolint ignore=DL3059
+RUN sed -i 's/# \(en_US.UTF-8\)/\1/' /etc/locale.gen && \
+    /usr/sbin/locale-gen && \
+	useradd -ms /bin/bash br-user && \
+    chown -R br-user:br-user /home/br-user
+
+USER br-user
+
+WORKDIR /home/br-user
+
+ENV HOME=/home/br-user
+
+ENV LC_ALL=en_US.UTF-8
+
+ARG BR_VERSION=2021.11
+
+RUN git clone --depth 1 --branch ${BR_VERSION} https://git.busybox.net/buildroot
+
+FROM buildroot-base as rootfs
+
+WORKDIR /home/br-user/buildroot
+
+# set by buildkit (DOCKER_BUILDKIT=1)
+ARG TARGETARCH
+ARG TARGETVARIANT
+
+# musl or glibc (musl is smaller)
+ARG ROOTFS_LIBC=musl
+
+COPY config ./config
+
+RUN support/kconfig/merge_config.sh -m \
+	config/arch/"${TARGETARCH}${TARGETVARIANT}".cfg \
+	config/libc/"${ROOTFS_LIBC}".cfg \
+	config/*.cfg
+
+RUN --mount=type=cache,target=/cache,uid=1000,gid=1000,sharing=private \
+    make olddefconfig && make source && make
+
+# hadolint ignore=DL3002
+USER root
+
+WORKDIR /rootfs
+
+RUN tar xpf /home/br-user/buildroot/output/images/rootfs.tar -C /rootfs
+
+FROM scratch
+
+COPY --from=rootfs rootfs/ /
+
+ENTRYPOINT [ "/usr/bin/balena-engine-daemon" ]
+
+CMD [ "-H", "tcp://0.0.0.0:2375" ]

test/balena/NOTICE

@@ -0,0 +1,4 @@
+Dockerfile and content in `config` is taken from
+https://github.com/balena-io-experimental/balena-engine-docker which is
+distributed under the Apache-2.0 license:
+https://github.com/balena-io-experimental/balena-engine-docker/blob/532d24e746240a5d26bcd55112e8cf68dd6b8227/LICENSE

test/balena/config/arch/amd64.cfg

@@ -0,0 +1 @@
+BR2_x86_64=y

test/balena/config/arch/arm64.cfg

@@ -0,0 +1 @@
+BR2_aarch64=y

test/balena/config/arch/armv6.cfg

@@ -0,0 +1,2 @@
+BR2_arm=y
+BR2_arm1176jzf_s=y

test/balena/config/arch/armv7.cfg

@@ -0,0 +1 @@
+BR2_arm=y

test/balena/config/balena-engine.cfg

@@ -0,0 +1,3 @@
+BR2_PACKAGE_TINI=y
+BR2_PACKAGE_BALENA_ENGINE=y
+BR2_PACKAGE_CA_CERTIFICATES=y

test/balena/config/common.cfg

@@ -0,0 +1,20 @@
+BR2_TOOLCHAIN_BUILDROOT_CXX=y
+BR2_KERNEL_HEADERS_4_19=y
+BR2_GCC_ENABLE_LTO=y
+
+# We don't need init inside a container
+BR2_INIT_NONE=y
+
+# Also unselect busybox
+BR2_PACKAGE_BUSYBOX=n
+
+# We don't need a system shell or ifupdown-scripts
+BR2_SYSTEM_BIN_SH_NONE=y
+BR2_PACKAGE_IFUPDOWN_SCRIPTS=n
+
+# Setup cache paths
+BR2_DL_DIR="/cache/dl"
+
+BR2_CCACHE=y
+BR2_CCACHE_DIR="/cache/ccache"
+BR2_CCACHE_USE_BASEDIR=y

test/balena/config/libc/glibc.cfg

@@ -0,0 +1 @@
+BR2_TOOLCHAIN_BUILDROOT_GLIBC=y

test/balena/config/libc/musl.cfg

@@ -0,0 +1 @@
+BR2_TOOLCHAIN_BUILDROOT_MUSL=y

test/balena/docker-compose.yml

@@ -0,0 +1,30 @@
+version: '3'
+
+services:
+  balena:
+    build: .
+    privileged: true
+
+  backup:
+    image: offen/docker-volume-backup:${TEST_VERSION:-canary}
+    hostname: hostnametoken
+    restart: always
+    environment:
+      BACKUP_CRON_EXPRESSION: 0 0 5 31 2 ?
+      BACKUP_FILENAME: test.tar.gz
+      DOCKER_HOST: tcp://balena:2375
+    volumes:
+      - ${LOCAL_DIR:-./local}:/archive
+      - app_data:/backup/app_data:ro
+
+  offen:
+    image: offen/offen:latest
+    labels:
+      - docker-volume-backup.stop-during-backup=true
+    volumes:
+      - app_data:/var/opt/offen
+
+volumes:
+  minio_backup_data:
+    name: minio_backup_data
+  app_data:

test/balena/run.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+set -e
+
+cd $(dirname $0)
+. ../util.sh
+current_test=$(basename $(pwd))
+
+export LOCAL_DIR=$(mktemp -d)
+
+docker compose up -d
+
+sleep 20
+
+expect_running_containers "3"
+
+docker compose exec backup backup
+
+sleep 5
+
+if [ ! -f $LOCAL_DIR/test.tar.gz ]; then
+  fail "Archive was not created"
+fi
+pass "Found expected file."
+
+expect_running_containers "3"