Add possibility to esclude directories from backup

Author: Leen15

.gitignore

@@ -0,0 +1,3 @@
+.idea
+.env
+vendor/*

README.md

@@ -2,6 +2,8 @@
 Backups a directory to S3 after gzipping it and checking if it's different from the last one.
 This avoids to upload multiple backups that are all equals.
 
+You can also exclude one or more directories from the backup just adding an empty file `exclude_dir_from_backup` inside every directory.
+
 Image runs as a cron job by default evey minute. Period may be changed by tuning `BACKUP_CRON_SCHEDULE` environment variable.
 
 May also be run as a one time backup job by using `backup.sh` script as command.
@@ -33,6 +35,7 @@ If you want to keep the archive files created, mount a volume on `BACKUP_TGT_DIR
 
 If you want to store files on S3 under a subdirectory, just add it to the `BACKUP_S3_BUCKET` like `BACKUP_S3_BUCKET=bucket_name/subdirectory_for_storage`.
 
+
 #### Examples
 
 Mount the dir you want to be backed up on `BACKUP_SRC_DIR` and run image as daemon for periodic backup:

backup.sh

@@ -14,7 +14,7 @@ BACKUP_DST_DIR=$(dirname "${BACKUP_DST_FULL_PATH}")
 
 mkdir -p ${COMPARE_DIR}
 echo "Gzipping ${BACKUP_SRC_DIR} into ${COMPARE_DST_FULL_PATH}" 
-tar -czf ${COMPARE_DST_FULL_PATH} -C ${BACKUP_SRC_DIR} .
+tar -czf ${COMPARE_DST_FULL_PATH} --exclude-tag-all=exclude_dir_from_backup -C ${BACKUP_SRC_DIR} .
 
 if cmp -s -i 8 "$BACKUP_DST_FULL_PATH" "$COMPARE_DST_FULL_PATH"
 then