Cloud.File.Storage.Manager.Box 1.1.0

Cloud File Storage Manager

Provides complete implementation to handle easily cloud file storage operations like get informations about files, reading, downloadURL generation, file update, file move and delete. Primarily for Box right now.

Configuration

Let's add a section to the appsettings.json

"BoxStorageSettings": {
    "ClientId": "",
    "ClientSecret": "",
    "EnterpriseId": "",
    "PublicKeyId": "",
    "PrivateKey": "",
    "Passphrase": "",
    "RootFolderId": "0"
}

In the application, configure this settings part

services.AddSingleton<ICloudFileStorageManager, BoxCloudFileStorageManager>(services => new BoxCloudFileStorageManager(new BoxCloudFileStorageManagerOptions()
{
    ClientId = config.GetSection("BoxStorageSettings").GetValue<string>("ClientId"),
    ClientSecret = config.GetSection("BoxStorageSettings").GetValue<string>("ClientSecret"),
    EnterpriseId = config.GetSection("BoxStorageSettings").GetValue<string>("EnterpriseId"),
    PublicKeyId = config.GetSection("BoxStorageSettings").GetValue<string>("PublicKeyId"),
    PrivateKey = config.GetSection("BoxStorageSettings").GetValue<string>("PrivateKey"),
    Passphrase = config.GetSection("BoxStorageSettings").GetValue<string>("Passphrase"),
    RootFolderId = config.GetSection("BoxStorageSettings").GetValue<string>("RootFolderId")
}));

PrivateKey is the PEM private key from the Box config file. A key copied with escaped newlines (\n or \r\n written as text, as it appears in the downloaded JSON config file) is accepted and converted to real line breaks.

RootFolderId is the id of the Box folder that acts as the root of the storage; "0" (the default when it is not set) is the root of the service account.

Behaviour

Paths

Paths are relative to RootFolderId (and to RootDirectoryPath, when set). Both / and \ separate segments, and name matching is case-insensitive.

A segment is rejected with an ArgumentException when it is empty or whitespace, consists only of dots and spaces, contains a control character, or does so after percent-decoding. A segment whose percent-decoded form contains / or \ is rejected as well.

Zero segments address the root folder itself: GetDirectoryContents() lists the root folder. ReadFile and GetDownloadUrl need at least one segment.

Root folder protection

The root folder (RootFolderId, or RootDirectoryPath when set) cannot be deleted, moved, renamed or overwritten. These calls throw an InvalidOperationException, also when a path resolves to the root folder by id.

Uploads

• Files below 20 MB are uploaded in a single request, larger files with a Box chunked upload session.
• Non-seekable streams (for example a network or request stream) are first spooled to a temporary file, so the size is known and the content is not held in memory. The temporary file is deleted when the upload finishes or fails.
• UpdateFileMode.Append downloads the current content, combines it with the new content in a temporary file and uploads the result as a new version of the file.
• Missing parent folders are created on upload. When a path segment exists as a file, the upload fails with an InvalidOperationException.

Listing and file information

• GetDirectoryContents pages through the folder and returns files and folders with their real sizes and modification times. Folders are reported with Exists = true and IsDirectory = true.
• The modification time is the Box modified_at value, falling back to content_modified_at.

Reading

ReadFile downloads the file into a temporary file that is deleted when the returned stream is disposed. When the download fails, the temporary file is removed right away.

Download links

GetDownloadUrl returns the temporary direct download link Box generates for the file. Box keeps the link valid for about 15 minutes; the validity argument is ignored. Folders have no download link and throw a FileNotFoundException.

Not supported

Watch is not supported and throws a NotSupportedException.

Images of the Box side configuration

Let's create a Platform Application

It is necessary to Enable the applicaiton and Authorization from administrators is required. After that, a service account is created for the Platform application with which the API interaction takes place.

JWT type application is recommended for this kind of use-cases

Minimal access is sufficient

Public/Private Keypair

A Public/Private Keypair is required for the necessary configuration, which can be created with the click of a button. A config file is also downloaded here, which contains all the necessary configuration data required for the configuration. (ClientId, Keys, etc.)

When using a Box Platform App with JWT authentication, your app acts as a service account, also called an App User. This service account is isolated from your personal Box account.

• Files and folders uploaded using JWT don't show up in "All Files" in your personal Box account — because they are not stored in your user’s root folder, but in the service account’s storage space.

Where did your files go?

If you're using JWT to authenticate via the platform app and then uploading files:

• The uploads are happening under the App User's account, not your personal Box user.
• Unless you explicitly upload to a folder owned/shared by a managed user (like yourself), it goes into the App User’s own root.