Merge pull request #8 from christophetd/pre_post_scripts

Add support for pre-backup and post-backup scripts (closes #2)

README.md

@@ -119,6 +119,8 @@ More: see [Duplicacy's documentation](https://github.com/gilbertchen/duplicacy/w
 
 ## Other options
 
+You can have duplicacy-autobackup run a script before and after the backup process by mounting scripts on `/scripts/pre-backup.sh` and `/scripts/post-backup.sh`. For instance if you're backing up a MySQL database, this script can involve doing a `mysqldump` into `/data/mydb.sql`. If `pre-backup.sh` exits with a non-zero status code, the backup will not be performed until the next scheduled backup.
+
 Use the following environment variables if you want to customize duplicacy's behavior.
 
 - `BACKUP_IMMEDIATLY` (`yes`/`no`): indicates if a backup should be performed immediatly after the container is started. Equivalent to launching the container and then running `docker exec duplicacy-autobackup /app/duplicacy-autobackup.sh backup`. By default, `no`.

duplicacy-autobackup.sh

@@ -1,5 +1,8 @@
 #!/bin/sh
 
+PRE_BACKUP_SCRIPT="/scripts/pre-backup.sh"
+POST_BACKUP_SCRIPT="/scripts/post-backup.sh"
+
 cd /data
 
 do_init() {
@@ -20,7 +23,25 @@ do_init() {
 }
 
 do_backup() {
+  status=0
+  if [[ -f $PRE_BACKUP_SCRIPT ]]; then
+    echo "Running pre-backup script"
+    sh $PRE_BACKUP_SCRIPT
+    status=$?
+  fi
+  if [[ $status != 0 ]]; then
+    echo "Pre-backup script exited with status code $status. Not performing backup." >&2
+    return
+  fi
+
   duplicacy backup $DUPLICACY_BACKUP_OPTIONS
+
+  if [[ -f $POST_BACKUP_SCRIPT ]]; then
+    echo "Running post-backup script"
+    sh $POST_BACKUP_SCRIPT
+    status=$?
+    echo "Post-backup script exited with status $status"
+  fi
 }
 
 export DUPLICACY_PASSWORD=$BACKUP_ENCRYPTION_KEY

tests/test-pre-post-scripts.sh

@@ -0,0 +1,79 @@
+#!/bin/sh
+
+
+: ${AWS_ACCESS_KEY_ID:?"Missing AWS secret key"}
+: ${AWS_SECRET_ACCESS_KEY:?"Missing AWS secret key"}
+
+TEST_BUCKET=duplicacy-autobackup-tests
+REGION=eu-central-1
+BACKUP_LOCATION="s3://$REGION@amazon.com/$TEST_BUCKET"
+IMAGE_NAME=duplicacy-autobackup # local image
+PASSPHRASE='correct horse battery staple'
+BACKUP_NAME='prod-db-backups'
+data_dir=$(mktemp -d)
+
+if [[ ! -z $(aws s3 ls $TEST_BUCKET) ]]; then
+    echo "Test bucket is not empty. Exiting" >&2
+    exit 1
+fi
+
+cleanup() {
+    echo 'Cleaning up...'
+    aws s3 rm s3://$TEST_BUCKET/ --recursive
+    docker rm -f duplicacy-autobackup
+    rm -f pre.sh
+    rm -f post.sh
+    rm -f $data_dir/post-script-executed
+    rm -f $data_dir/pre-script-executed
+}
+trap cleanup EXIT
+
+cat > $data_dir/hello.txt <<EOF
+    hello, world!
+EOF
+
+cat > pre.sh <<EOF
+    touch /data/pre-script-executed
+EOF
+
+cat > post.sh <<EOF
+    touch /data/post-script-executed
+EOF
+
+docker run -d --name duplicacy-autobackup \
+    -v $data_dir:/data \
+    -v $(pwd)/pre.sh:/scripts/pre-backup.sh \
+    -v $(pwd)/post.sh:/scripts/post-backup.sh \
+    -e BACKUP_NAME=$BACKUP_NAME \
+    -e BACKUP_LOCATION="$BACKUP_LOCATION" \
+    -e BACKUP_SCHEDULE='0 2 * * *' \
+    -e BACKUP_IMMEDIATLY='yes' \
+    -e BACKUP_ENCRYPTION_KEY="$PASSPHRASE" \
+    -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
+    -e AWS_SECRET_KEY=$AWS_SECRET_ACCESS_KEY \
+    $IMAGE_NAME
+
+echo "Waiting for backup to be performed..."
+sleep 10
+
+if [[ -z $(aws s3 ls $TEST_BUCKET) ]]; then
+    echo "Nothing in test bucket. Exiting" >&2
+    exit 2
+fi
+
+if [[ ! -d $data_dir/.duplicacy ]]; then
+    echo "No duplicacy folder created. Exiting" >&2
+    exit 3
+fi
+
+echo "Backup performed"
+
+if [[ ! -f $data_dir/pre-script-executed ]]; then
+    echo "Pre backup script wasn't executed" >&2
+    exit 4
+elif [[ ! -f $data_dir/post-script-executed ]]; then
+    echo "Pre backup script wasn't executed" >&2
+    exit 5
+fi
+
+echo "Pre and post backup script properly executed"