File Transfer Service

The file transfer service is provided as a generic file repository service. While other services can also store and manage their own assets (files), this service could also be used instead of implementing a service that only stores files.

Main script

The File Transfer service can be launched by running the FileTransferService.py script. As a system service, it is also launched automatically when running the main OpenTera service.

Configuration

Configuration files for the file transfer service are similar to the basic configuration files. They, however, add a specific section for that service.

FileTransfer config section

files_directory: the relative or full path to store transferred files on the server.

Default port and location

By default, the service will listen to port 4042 (non-ssl) and will be at /file behind the NGINX router.

Code snippets and examples for POST, GET and DELETE

Upload a file using POST request

Each file needs to be attached to a session. No session are created in the upload process - make sure that the session exists beforehand by using the appropriate API.

When uploading a file, you need to specify 2 mandatory components for the request:

file_asset describing the file itself, containing at minimum the asset_name and id_session to attach the file to.
file containing the data for the file itself.

Make sure to have the token generated from the logging procedure when doing this request.

This is a snippet of the data to send as a .json format to the server excluding the file. For the file part you need to specify its package which depends on the library you are using to communicate with the server.

`file_asset` json format example

{
  "file_asset": {
    "asset_name": "Asset Name",
    "id_session": 1
  }
}

Python requests POST example

import requests

url = "URL of the server with the FileTransfer API"

payload={'file_asset': '{"id_session": "Session number", "asset_name": "Asset Name"}'}
files=[
  ('file',('filename',open('PATH to file','rb'),'application type (ex: application/zip)'))
]
headers = {
  'Authorization': 'OpenTera {Previously obtained token}'
}

response = requests.request("POST", url, headers=headers, data=payload, files=files)

print(response.text)

Testing and generating POST requests

If you want snippets in other programming languages, PostMan can be used to test API calls and get snippets of code.

Using PostMan to test POST queries

To generate a POST request on Postman:

Specify the body as form-data with the file_asset and file key.
Select the key type as file for the file and select the file you want to upload.
Make sure to have a token generated from the server when logging in. This API request needs a token in the Headers in the format: Authorization : OpenTera {{token}}. The token can be set as a environment variable that is updated when you launch the login GET request.
Click on the Code section and get snippets in any languages you desire.

Download and Delete a file using GET and DELETE request

Refer to the service documentation on a running server at https://127.0.0.1:40075/file/doc

Web URLs and REST API

Doc page - by default at https://127.0.0.1:40075/file/doc. Will display the REST API documentation and test system. Useful to test queries manually.

Web Frontend

Currently, no web front-end is available for that service

RPC API

None. This service uses the asynchronous communication system.