# Updating an application

To update an application to the current version of wolkenkit follow the steps given below.

# Danger of data loss

wolkenkit 2.0.0 contains a bug that led to ignoring the --shared-key flag of the CLI.

Most important, don't restart your application unless you have exported your data as a backup. wolkenkit 2.0.0 unfortunately ignored the --shared-key flag, which means that your data is not stored permanently. Hence, if you restart your application, your data will be lost.

To backup your data, you first have to update the CLI to version 3.0.0. If you have installed the CLI globally, run the following command:

$ npm install -g wolkenkit@3.0.0

If you have installed the CLI into the local context of your application, use the following command:

$ npm install wolkenkit@3.0.0 --save-dev

Next, you need to export your application's data. For that, run the wolkenkit export command and provide a directory that you want to export your application's data into. This directory must either be empty or non-existent; if it doesn't exist, it will be created automatically::

$ wolkenkit export --to <directory>

Please note that this only exports the events from the event store. Any files you uploaded to the file storage need to be exported manually.

Stop your application using the wolkenkit stop command:

$ wolkenkit stop

Now, update your application's code according to this guide. Once you are ready to start your application again, use the wolkenkit start command, and provide the desired shared key:

$ wolkenkit start --shared-key <shared-key>

Make sure that your application is not yet used, as the event store must be empty for re-importing your previously exported data. To import the data, use the wolkenkit import command and provide the directory that contains the previously exported data:

$ wolkenkit import --from <directory>

To finalize the import, run the wolkenkit reload command on your application:

$ wolkenkit reload

Once your application is up and running again, it can be used as normal. For details on the new export and import commands, see exporting and importing data.

# package.json

Previous version (2.0.0)

"wolkenkit": {
  "application": "your-app",
  "runtime": {
    "version": "2.0.0"
  },
  "environments": {
    "default": {
      "api": {
        "...": "..."
      }
    }
  },
  "...": "..."
}

Current version (3.0.0)

"wolkenkit": {
  "application": "your-app",
  "runtime": {
    "version": "3.0.0"
  },
  "environments": {
    "default": {
      "api": {
        "...": "..."
      },
      "fileStorage": {
        "allowAccessFrom": "*"
      }
    }
  },
  "...": "..."
}

# Client

The client SDK now requires using a polyfill if you are targeting Internet Explorer 11. Therefore, use the @babel/polyfill module.

# File storage

Up to wolkenkit 2.0.0, you had to access the file storage service manually by sending appropriate HTTP requests. In wolkenkit 3.0.0 the HTTP API changed. To get an overview, see using the HTTP API. There is now also a client SDK for accessing the file storage service in a convenient way, which is described in detail at using the depot SDK.

Besides adjusting your code please note that you also have to configure file storage. In its simplest form this is done by adding the following section to your application's package.json file:

"wolkenkit": {
  "environments": {
    "default": {
      "fileStorage": {
        "allowAccessFrom": "*"
      }
    }
  }
}

For details on how to use the SDK see storing large files. For further information on configuring the file storage service, see configuring file storage.