build mc from source, support arm/v7

Build image for arm architectures

.circleci/config.yml

@@ -1,40 +1,70 @@
 version: 2.1
 
 jobs:
-  build:
+  canary:
     docker:
       - image: cimg/base:2020.06
     working_directory: ~/docker-volume-backup
     steps:
       - checkout
-      - setup_remote_docker
+      - setup_remote_docker:
+          version: 20.10.6
       - run:
           name: Build
-          command: make build
-      - run:
-          name: Check if image needs to be pushed
           command: |
-            if [[ -z "$CIRCLE_TAG" ]]; then
+            docker build . -t offen/docker-volume-backup:canary
-              echo "Not a git tag, nothing to do ..."
+      - run:
-              circleci-agent step halt
+          name: Create container from image
+          command: |
+            docker run -d offen/docker-volume-backup:canary
+            echo "Sleeping for 30s before checking if container is still running."
+            sleep 30
+            count=$(docker ps -q | wc -l)
+            if [[ $count != "1" ]]; then
+              echo "Expected one container to be running, found $count."
+              exit 1
             fi
+            docker stop $(docker ps -q)
+
+  build:
+    docker:
+      - image: cimg/base:2020.06
+        environment:
+          DOCKER_BUILDKIT: '1'
+          DOCKER_CLI_EXPERIMENTAL: enabled
+    working_directory: ~/docker-volume-backup
+    steps:
+      - checkout
+      - setup_remote_docker:
+          version: 20.10.6
       - docker/install-docker-credential-helper
       - docker/configure-docker-credentials-store
       - run:
           name: Push to Docker Hub
           command: |
             echo "$DOCKER_ACCESSTOKEN" | docker login --username offen --password-stdin
-            docker tag offen/docker-volume-backup:local offen/docker-volume-backup:$CIRCLE_TAG
+            # This is required for building ARM: https://gitlab.alpinelinux.org/alpine/aports/-/issues/12406
-            docker tag offen/docker-volume-backup:local offen/docker-volume-backup:latest
+            docker run --rm --privileged linuxkit/binfmt:v0.8
-            docker push offen/docker-volume-backup:$CIRCLE_TAG
+            docker context create docker-volume-backup
-            docker push offen/docker-volume-backup:latest
+            docker buildx create docker-volume-backup --name docker-volume-backup --use
+            docker buildx inspect --bootstrap
+            docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 \
+              -t offen/docker-volume-backup:$CIRCLE_TAG \
+              -t offen/docker-volume-backup:latest \
+              . --push
 
 workflows:
   version: 2
-  deploy:
+  docker_image:
     jobs:
+      - canary:
+          filters:
+            tags:
+              ignore: /^v.*/
       - build:
           filters:
+            branches:
+              ignore: /.*/
             tags:
               only: /^v.*/
 

Dockerfile

@@ -1,16 +1,20 @@
 # Copyright 2021 - Offen Authors <hioffen@posteo.de>
-# SPDX-License-Identifier: MIT
+# SPDX-License-Identifier: MPL-2.0
 
-FROM alpine:3.13
+FROM golang:1.16-alpine as builder
+ARG MC_VERSION=RELEASE.2021-06-13T17-48-22Z
+RUN go install github.com/minio/mc@$MC_VERSION
+
+FROM alpine:3.14
 
 WORKDIR /root
 
 RUN apk add --update ca-certificates docker openrc gnupg
+RUN update-ca-certificates
 RUN rc-update add docker boot
 
-RUN wget https://dl.min.io/client/mc/release/linux-amd64/mc && \
+COPY --from=builder /go/bin/mc /usr/bin/mc
-  chmod +x mc && \
+RUN mc --version
-  mv mc /usr/bin/mc
 
 COPY src/backup.sh src/entrypoint.sh /root/
 RUN chmod +x backup.sh && mv backup.sh /usr/bin/backup \

Makefile

@@ -1,5 +0,0 @@
-DOCKER_TAG ?= local
-
-.PHONY: build
-build:
-	@docker build -t offen/docker-volume-backup:$(DOCKER_TAG) .

README.md

@@ -38,11 +38,39 @@ AWS_S3_BUCKET_NAME="<xxx>"
 
 # BACKUP_RETENTION_DAYS="7"
 
+# In case the duration a backup takes fluctuates noticeably in your setup
+# you can adjust this setting to make sure there are no race conditions
+# between the backup finishing and the pruning not deleting backups that
+# sit on the very edge of the time window. Set this value to a duration
+# that is expected to be bigger than the maximum difference of backups.
+# Valid values have a suffix of (s)econds, (m)inutes, (h)ours, or (d)ays.
+
+# BACKUP_PRUNING_LEEWAY="10m"
+
 ########### BACKUP ENCRYPTION
 
 # Backups can be encrypted using gpg in case a passphrase is given
 
 # GPG_PASSPHRASE="<xxx>"
+
+########### STOPPING CONTAINERS DURING BACKUP
+
+# Containers can be stopped by applying a
+# `docker-volume-backup.stop-during-backup` label. By default, all containers
+# that are labeled with `true` will be stopped. If you need more fine grained
+# control (e.g. when running multiple containers based on this image), you can
+# override this default by specifying a different value here.
+
+# BACKUP_STOP_CONTAINER_LABEL="service1"
+
+########### MINIO CLIENT CONFIGURATION
+
+# Pass these additional flags to all MinIO client `mc` invocations.
+# This can be used for example to pass `--insecure` when using self
+# signed certificates, or passing `--debug` to gain insights on
+# unexpected behavior.
+
+# MC_GLOBAL_OPTIONS="<xxx>"
 ```
 
 ## Example in a docker-compose setup
@@ -86,3 +114,4 @@ This image is heavily inspired by the `futurice/docker-volume-backup`. We decide
 - This image makes use of the MinIO client `mc` instead of the full blown AWS CLI for uploading backups.
 - The original image proposed to handle backup rotation through AWS S3 lifecycle policies. This image adds the option to rotate old backups through the same script so this functionality can also be offered for non-AWS storage backends like MinIO.
 - InfluxDB specific functionality was removed.
+- `arm64` and `arm/v7` architectures are supported.

src/backup.sh

@@ -19,7 +19,7 @@ if [ -S "$DOCKER_SOCK" ]; then
   TEMPFILE="$(mktemp)"
   docker ps \
     --format "{{.ID}}" \
-    --filter "label=docker-volume-backup.stop-during-backup=true" \
+    --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 $TEMPFILE | wc -l)"
@@ -58,7 +58,7 @@ fi
 if [ ! -z "$AWS_S3_BUCKET_NAME" ]; then
   info "Uploading backup to remote storage"
   echo "Will upload to bucket \"$AWS_S3_BUCKET_NAME\"."
-  mc cp "$BACKUP_FILENAME" "backup-target/$AWS_S3_BUCKET_NAME"
+  mc cp $MC_GLOBAL_OPTIONS "$BACKUP_FILENAME" "backup-target/$AWS_S3_BUCKET_NAME"
   echo "Upload finished."
 fi
 
@@ -76,14 +76,14 @@ if [ ! -z "$BACKUP_RETENTION_DAYS" ]; then
   sleep "$BACKUP_PRUNING_LEEWAY"
   bucket=$AWS_S3_BUCKET_NAME
 
-  rule_applies_to=$(mc rm --fake --recursive -force --older-than "${BACKUP_RETENTION_DAYS}d" "backup-target/$bucket" | wc -l)
+  rule_applies_to=$(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=$(mc ls "backup-target/$bucket" | wc -l)
+  total=$(mc ls $MC_GLOBAL_OPTIONS "backup-target/$bucket" | wc -l)
 
   if [ "$rule_applies_to" == "$total" ]; then
     echo "Using a retention of ${BACKUP_RETENTION_DAYS} days would prune all currently existing backups, will not continue."
@@ -91,6 +91,6 @@ if [ ! -z "$BACKUP_RETENTION_DAYS" ]; then
     exit 1
   fi
 
-  mc rm --recursive -force --older-than "${BACKUP_RETENTION_DAYS}d" "backup-target/$bucket"
+  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

src/entrypoint.sh

@@ -21,11 +21,15 @@ AWS_S3_BUCKET_NAME="${AWS_S3_BUCKET_NAME:-}"
 AWS_ENDPOINT="${AWS_ENDPOINT:-s3.amazonaws.com}"
 
 GPG_PASSPHRASE="${GPG_PASSPHRASE:-}"
+
+BACKUP_STOP_CONTAINER_LABEL="${BACKUP_STOP_CONTAINER_LABEL:-true}"
+
+MC_GLOBAL_OPTIONS="${MC_GLOBAL_OPTIONS:-}"
 EOF
 chmod a+x env.sh
 source env.sh
 
-mc alias set backup-target "https://$AWS_ENDPOINT" "$AWS_ACCESS_KEY_ID" "$AWS_SECRET_ACCESS_KEY"
+mc $MC_GLOBAL_OPTIONS alias set backup-target "https://$AWS_ENDPOINT" "$AWS_ACCESS_KEY_ID" "$AWS_SECRET_ACCESS_KEY"
 
 # Add our cron entry, and direct stdout & stderr to Docker commands stdout
 echo "Installing cron.d entry with expression $BACKUP_CRON_EXPRESSION."