Data transfers package

[ishank011]

Previously, we had to configure which data transfer protocol to use in the dataprovider service. A previous PR added the functionality to redirect requests to different handlers based on the request method but that would lead to conflicts if multiple protocols don't support mutually exclusive sets of requests. This PR adds the functionality to have multiple such handlers simultaneously and the client can choose which protocol to use.

Depends on cs3org/cs3apis#96, currently uses my fork https://github.com/ishank011/go-cs3apis

InitiateFileUpload response now looks like:

{
  "status": {
    "code": 1
  },
  "protocols": [
    {
      "protocol": "simple",
      "upload_endpoint": "http://localhost:19001/datagateway",
      "available_checksums": [
        {
          "type": 3,
          "priority": 100
        },
        {
          "type": 1,
          "priority": 1000
        }
      ],
      "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJyZXZhIiwiZXhwIjoxNjA1NjM2MzQ0LCJpYXQiOjE2MDU2MzAzNDQsInRhcmdldCI6Imh0dHA6Ly9sb2NhbGhvc3Q6MTcwMDEvZGF0YS9zaW1wbGUvYjk1YjhlOGUtYTgwYi00NjMxLWI3OTgtNTJjY2ZjOGExMTM1In0.g68M_LkQ9Loaz9sJedMK_DmrNMhKwe2R0NNC7gtwYvw"
    },
    {
      "protocol": "tus",
      "upload_endpoint": "http://localhost:19001/datagateway",
      "available_checksums": [
        {
          "type": 3,
          "priority": 100
        },
        {
          "type": 1,
          "priority": 1000
        }
      ],
      "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdWQiOiJyZXZhIiwiZXhwIjoxNjA1NjM2MzQ0LCJpYXQiOjE2MDU2MzAzNDQsInRhcmdldCI6Imh0dHA6Ly9sb2NhbGhvc3Q6MTcwMDEvZGF0YS90dXMvYjk1YjhlOGUtYTgwYi00NjMxLWI3OTgtNTJjY2ZjOGExMTM1In0.AhV2jABWns8t8-YiEQkzAleuTnL5kpVEYxbpOebtCYM"
    }
  ]
}

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[labkode]

@ishank011 I merged the cs3apis, let's change the dep to it

[labkode]

@ishank011 should we remove the sdk test files?

[ishank011]

@labkode Yes we can. I didn't like the idea of calling a remote server to run unit tests in the first place.

@Daniel-WWU-IT can you modify these to run on a local reva daemon?

[labkode]

@ishank011 still one conflict to resolve