New: DataSource controller for procets coscine/issues#209

src/Project/Controllers/DataSourceController.cs

+using Coscine.Api.Project.ReturnObjects;
+using Coscine.ApiCommons.Utils;
+using Coscine.Configuration;
+using Microsoft.AspNetCore.Mvc;
+using Newtonsoft.Json.Linq;
+using System.Collections.Generic;
+using System.IdentityModel.Tokens.Jwt;
+using System.Linq;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading.Tasks;
+
+namespace Coscine.Api.Project.Controllers
+{
+    public class DataSourceController : Controller
+    {
+        private readonly IConfiguration _configuration;
+        private readonly JWTHandler _jwtHandler;
+        private readonly static HttpClient _client = new HttpClient();
+        public DataSourceController()
+        {
+            _configuration = new ConsulConfiguration();
+            _jwtHandler = new JWTHandler(_configuration);
+        }
+
+        [HttpGet("[controller]/{*path}")]
+        public async Task<IActionResult> Get(string path)
+        {
+            // inferring a ../ (urlencoded) can manipulate the url.
+            // However the constructed signature for s3 won't match and it will not be resolved.
+            // If the path is null, an empty string is added.
+            string url = $"http://localhost:7777/v1/resources/0/providers/rds/{path}";
+
+            var request = new HttpRequestMessage(HttpMethod.Get, url);
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", BuildAuthHeader());
+
+            // Thread safe according to msdn and HttpCompletionOption sets it to get only headers first.
+            var response = await _client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
+            if (response.IsSuccessStatusCode)
+            {
+                if (response.Content.Headers.Contains("Content-Disposition"))
+                {
+                    return File(await response.Content.ReadAsStreamAsync(), 
+                        response.Content.Headers.GetValues("Content-Type").First());
+                }
+                else
+                {
+                    var data = JObject.Parse(await response.Content.ReadAsStringAsync())["data"];
+                    return Ok(new WaterbutlerObject(path, data));
+                }
+            }
+            else
+            {
+                if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+                {
+                    return NotFound($"Coukd not find object for: \"{path}\".");
+                }
+                else
+                if (response.StatusCode == System.Net.HttpStatusCode.Forbidden)
+                {
+                    return Forbid($"Not allowed to access the datasource.");
+                }
+                else
+                {
+                    return BadRequest($"Error in communication with waterbutler: {response.StatusCode}");
+                }
+            }
+        }
+
+        private string BuildAuthHeader()
+        {
+            var auth = new Dictionary<string, object>();
+
+            var credentials = new Dictionary<string, object>
+                    {
+                        { "access_key", _configuration.GetString("coscine/global/rds_access_key") },
+                        { "secret_key", _configuration.GetString("coscine/global/rds_secret_key") }
+                    };
+
+            var settings = new Dictionary<string, object>
+                    {
+                        { "bucket", "PITLABTTEST" }
+                    };
+
+            var data = new Dictionary<string, object>
+                    {
+                        { "auth", auth },
+                        { "credentials", credentials },
+                        { "settings", settings },
+                        { "callback_url", "rwth-aachen.de" }
+                    };
+
+            var payload = new JwtPayload
+                    {
+                        { "data", data }
+                    };
+
+            return _jwtHandler.GenerateJwtToken(payload);
+        }
+    }
+}

src/Project/Project.csproj

@@ -563,6 +563,7 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Controllers\DataSourceController.cs" />
     <Compile Include="Controllers\ProjectController.cs" />
     <Compile Include="Controllers\ResourceController.cs" />
     <Compile Include="Controllers\ResourceTypeController.cs" />
@@ -585,6 +586,7 @@
     <Compile Include="ReturnObjects\ResourceTypeObject.cs" />
     <Compile Include="ReturnObjects\RoleObject.cs" />
     <Compile Include="ReturnObjects\UserObject.cs" />
+    <Compile Include="ReturnObjects\WaterbutlerFolder.cs" />
     <Compile Include="Startup.cs" />
   </ItemGroup>
   <ItemGroup>

src/Project/ReturnObjects/WaterbutlerFolder.cs

+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json.Linq;
+
+namespace Coscine.Api.Project.ReturnObjects
+{
+    public class WaterbutlerObject
+    {
+        public bool IsFolder { get; set; } = false;
+        public string Absolutepath { get; set; } = null;
+        public string Name { get; set; } = null;
+        // Shallow! Only one level deep. 
+        // Should the folder contain additional folders, they will be empty/null.
+        public List<WaterbutlerObject> Content { get; set; } = null;
+
+        public WaterbutlerObject()
+        {
+
+        }
+
+        public WaterbutlerObject(string path, JToken data)
+        {
+            Absolutepath = string.IsNullOrWhiteSpace(path) ? "/" : $"/{path}";
+            Content = new List<WaterbutlerObject>();
+            IsFolder = true;
+
+            if (data == null)
+            {
+                throw new ArgumentNullException("The data for the WaterbutlerFolder cannot be null.");
+            }
+
+            foreach (var obj in data)
+            {
+                if (obj["type"].ToObject<string>() == "files")
+                {
+                    Content.Add(new WaterbutlerObject
+                    {
+                        IsFolder = obj["attributes"]["kind"].ToObject<string>() == "folder",
+                        Absolutepath = obj["attributes"]["path"].ToObject<string>(),
+                        Name = obj["attributes"]["name"].ToObject<string>()
+                    });
+                }
+            }
+        }
+    }
+}