more words

Specification.md

@@ -13,17 +13,30 @@ When backing up a docker stack you MUST first check if the `backupbot.backup`. I
 ## Backup
 
 To enable backups for a docker stack, the `backupbot.backup=true` label MUST be on any of its services. It SHOULD be declared on the first service.
-A `backupbot.backup.pre-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service before backup up files.
+
-By default all volumes MUST be backed up. A volume MAY be excluded from backing up when `backupbot.backup.volumes.{volume_name}=false` is set, where `{volume_name}` is the name of the volume.
+### Volumes and paths
+
+By default all volumes MUST be backed up. A volume MAY be excluded from the backup when `backupbot.backup.volumes.{volume_name}=false` is set, where `{volume_name}` is the name of the volume.
 By default all files MUST be backed up on a volume. `backupbot.backup.volumes.{volume_name}.path` MAY be set to limit the paths for that volume. The value MUST be a valid path relative to the volume root. It MAY contain multiple paths which get seperated by a comma.
-A `backupbot.backup.post-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service after backing up all files.
+
-A backup implementation SHOULD provide the backup of one or multiple stacks in a `.tar.gz` format.
+### Pre/Post Hooks
+
+A `backupbot.backup.pre-hook` and `backupbot.backup.post-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service before/after backing up files.
+The command MUST have access to all environment variables inside the container.
+There is no guaranteed order in which different hooks MUST be executed.
+
+### Output
+
+A backup implementation SHOULD provide the backup of one or multiple stacks in a `.tar.gz` format. In that case each volume MUST be in `/var/lib/docker/volumes/{volume_name}`, where `{volume_name}` is the name of each volume that got backed up.
 
 ## Restore
 
-A `backupbot.restore.pre-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service before restoring backup files.
+By default all files MUST be restored into their volume. A volume or path MAY be excluded from restoring. When restoring a backup from a `.tar.gz` it expects the directory layout as described int the [backup output](#output) section.
-By default all files MUST be restored into their volume. A volume or path MAY be excluded from restoring.
+
-A `backupbot.restore.post-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service after restoring backup files.
+### Pre/Post Hooks
+
+A `backupbot.restore.pre-hook` and `backupbot.restore.post-hook` MAY be set on a service. When set the command MUST be executed inside the running container of the service before/after restoring the files.
+There is no guaranteed order in which different hooks MUST be executed.
 
 ## Labels
 
@@ -97,6 +110,7 @@ backupbot.backup.post-hook: "rm -rf /volume_path/dump.db"
 **Default:** ""
 **Description:**
 A command, that gets executed before the files are restored.
+Note, that there is no guaranteed order in which multiple hooks get executed.
 
 **Example:**