Multiple sessions with Fluent NHibernate and Ninject - nhibernate

I am working on setting up a multi-tenant, seperate database application and have made some good progress from reading this post below on stackoverflow.
Multitenancy with Fluent nHibernate and Ninject. One Database per Tenant
I see two sessions being setup. One is the 'master' session that will be used to get the tenant information and then the tenant session which is specific to the subdomain. I have the app switching nicely to the specified database based on domain and have questions on how to setup the 'master' database session and how to use it.
I tried registering a new session specifically for the master session be get an error regarding having already registered an ISession.
I'm new to nHibernate and not sure the best route to take on this.
NinjectWebCommon.cs
kernel.Bind<WebApplication1.ISessionSource>().To<NHibernateTenantSessionSource>().InSingletonScope();
kernel.Bind<ISession>().ToMethod(c => c.Kernel.Get<WebApplication1.ISessionSource>().CreateSession());
kernel.Bind<ITenantAccessor>().To<DefaultTenantAccessor>();
ITenantAccessor.cs
public Tenant GetCurrentTenant()
{
var host = HttpContext.Current.Request.Url != null ? HttpContext.Current.Request.Url.Host : string.Empty;
var pattern = ConfigurationManager.AppSettings["UrlRegex"];
var regex = new Regex(pattern);
var match = regex.Match(host);
var subdomain = match.Success ? match.Groups[1].Value.ToLowerInvariant() : string.Empty;
Tenant tenant = null;
if (subdomain != null)
{
// Get Tenant info from Master DB.
// Look up needs to be cached
DomainModel.Master.Tenants tenantInfo;
using (ISession session = new NHibernateMasterSessionSource().CreateSession())
{
tenantInfo = session.CreateCriteria<DomainModel.Master.Tenants>()
.Add(Restrictions.Eq("SubDomain", subdomain))
.UniqueResult<WebApplication1.DomainModel.Master.Tenants>();
}
var connectionString = string.Format(ConfigurationManager.AppSettings["TenanatsDataConnectionStringFormat"],
tenantInfo.DbName, tenantInfo.DbUsername, tenantInfo.DbPassword);
tenant = new Tenant();
tenant.Name = subdomain;
tenant.ConnectionString = connectionString;
}
return tenant;
}
Thanks for you time on this.

Add another session binding and add some condition. E.g.
kernel
.Bind<ISession>()
.ToMethod(c => c.Kernel.Get<NHibernateMasterSessionSource>().CreateSession())
.WhenInjectedInto<TenantEvaluationService>();

Related

Managing CosmosDb Session Consistency levels with Session Token in web environment

My environment is ASP.NET Core 2.x accessing CosmosDb (aka DocumentDb) with the .NET SDK.
The default consistency level of my collection is set to "Session". For my use-case I need a single authenticated web user to always have consistent data in terms of reads/writes between web requests.
I have some CosmosDB Repository logic that is made available to my controller logic via ASP.NET Core Singleton dependency injection as such:
services.AddSingleton<DocumentDBRepository, DocumentDBRepository>(x =>
new DocumentDBRepository(
WebUtil.GetMachineConfig("DOCDB_ENDPOINT", Configuration),
WebUtil.GetMachineConfig("DOCDB_KEY", Configuration),
WebUtil.GetMachineConfig("DOCDB_DB", Configuration),
"MyCollection",
maxDocDbCons));
DocumentDBRespository creates a cosmos client like so:
public DocumentDBRepository(string endpoint, string authkey, string database, string collection, int maxConnections)
{
_Collection = collection;
_DatabaseId = database;
_Client = new DocumentClient(new Uri(endpoint), authkey,
new ConnectionPolicy()
{
MaxConnectionLimit = maxConnections,
ConnectionMode = ConnectionMode.Direct,
ConnectionProtocol = Protocol.Tcp,
RetryOptions = new RetryOptions()
{
MaxRetryAttemptsOnThrottledRequests = 10
}
});
_Client.OpenAsync().Wait();
CreateDatabaseIfNotExistsAsync().Wait();
CreateCollectionIfNotExistsAsync().Wait();
}
As far as I understand that means one CosmosDB client per Web App server. I do have multiple web app servers, so a single user might hit the CosmosDB from multiple AppServers and different CosmosDb clients.
Before a user interacts with the ComosDB, I check their session object for a CosmosDb SessionToken, like so:
string docDbSessionToken = HttpContext.Session.GetString("StorageSessionToken");
Then, when writing a document for example, the method looks something like so:
public async Task<Document> CreateItemAsync<T>(T item, Ref<string> sessionTokenOut, string sessionTokenIn = null)
{
ResourceResponse<Document> response = null;
if (string.IsNullOrEmpty(sessionTokenIn))
{
response = await _Client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(_DatabaseId, _Collection), item);
}
else
{
response = await _Client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(_DatabaseId, _Collection), item, new RequestOptions() { SessionToken = sessionTokenIn });
}
sessionTokenOut.Value = response.SessionToken;
Document created = response.Resource;
return created;
}
The idea being that if we have a session token, we pass one in and use it. If we don't have one, just create the document and then return the newly created session token back to the caller. This works fine...
Except, I'm unclear as to why when I do pass in a session token, I get a DIFFERENT session token back. In other words, when _Client.CreateDocumentAsync returns, response.SessionToken is always different from parameter sessionTokenIn.
Does that mean I should be using the new session token from that point on for that user? Does it mean I should ignore the new session token and use the initial session token?
How long do one of these "sessions" even last? Are they sessions in the traditional sense?
Ultimately, I just need to make sure that the same user can always read their writes, regardless of which AppServer they connect with or how many other users are currently using the DB.
I guess the confusion here is on what a session is?
In most scenarios/frameworks treat session as static identifier (correlation), where as with cosmos the sessionToken is dynamic (kind of bookmark/representation of cosmos db state, which changes with writes). Naming it as 'sessionToken' might be root of the confusion.
In this specific scenario, you should use the "returned sessiontoken" from cosmos API's.

RavenDB fails with ConcurrencyException when using new transaction

This code always fails with a ConcurrencyException:
[Test]
public void EventOrderingCode_Fails_WithConcurrencyException()
{
Guid id = Guid.NewGuid();
using (var scope1 = new TransactionScope())
using (var session = DataAccess.NewOpenSession)
{
session.Advanced.UseOptimisticConcurrency = true;
session.Advanced.AllowNonAuthoritativeInformation = false;
var ent1 = new CTEntity
{
Id = id,
Name = "George"
};
using (var scope2 = new TransactionScope(TransactionScopeOption.RequiresNew))
{
session.Store(ent1);
session.SaveChanges();
scope2.Complete();
}
var ent2 = session.Load<CTEntity>(id);
ent2.Name = "Gina";
session.SaveChanges();
scope1.Complete();
}
}
It fails at the last session.SaveChanges. Stating that it is using a NonCurrent etag. If I use Required instead of RequiresNew for scope2 - i.e. using the same Transaction. It works.
Now, since I load the entity (ent2) it should be using the newest Etag unless this is some cached value attached to scope1 that I am using (but I have disabled Caching). So I do not understand why this fails.
I really need this setup. In the production code the outer TransactionScope is created by NServiceBus, and the inner is for controlling an aspect of event ordering. It cannot be the same Transaction.
And I need the optimistic concurrency too - if other threads uses the entity at the same time.
BTW: This is using Raven 2.0.3.0
Since no one else have answered, I had better give it a go myself.
It turns out this was a human error. Due to a bad configuration of our IOC container the DataAccess.NewOpenSession gave me the same Session all the time (across other tests). In other words Raven works as expected :)
Before I found out about this I also experimented with using TransactionScopeOption.Suppress instead of RequiresNew. That also worked. Then I just had to make sure that whatever I did in the suppressed scope could not fail. Which was a valid option in my case.

ASP.NET Active Directory Search

I'm trying to create an intranet Website on ASP.NET MVC 4 using Windows Login. I have successfully done the windows login. The only thing I am stuck up with is searching the active directory with partial username. I tried searching the web and stackoverflow website but still couldn't find the answer.
DirectoryEntry directory = new DirectoryEntry("LDAP://DC=NUAXIS");
string filter = "(&(cn=jinal*))";
string[] strCats = { "cn" };
List<string> items = new List<string>();
DirectorySearcher dirComp = new DirectorySearcher(directory, filter, strCats, SearchScope.Subtree);
SearchResultCollection results = dirComp.FindAll();
You can use a PrincipalSearcher and a "query-by-example" principal to do your searching:
// create your domain context
using (PrincipalContext ctx = new PrincipalContext(ContextType.Domain))
{
// define a "query-by-example" principal - here, we search for a UserPrincipal
// and with the first name (GivenName) of "Jinal*"
UserPrincipal qbeUser = new UserPrincipal(ctx);
qbeUser.GivenName = "Jinal*";
// create your principal searcher passing in the QBE principal
using (PrincipalSearcher srch = new PrincipalSearcher(qbeUser))
{
// find all matches
foreach(var found in srch.FindAll())
{
// do whatever here - "found" is of type "Principal" -
// it could be user, group, computer.....
}
}
}
If you haven't already - absolutely read the MSDN article Managing Directory Security Principals in the .NET Framework 3.5 which shows nicely how to make the best use of the new features in System.DirectoryServices.AccountManagement. Or see the MSDN documentation on the System.DirectoryServices.AccountManagement namespace.
Of course, depending on your need, you might want to specify other properties on that "query-by-example" user principal you create:
DisplayName (typically: first name + space + last name)
SAM Account Name - your Windows/AD account name
User Principal Name - your "username#yourcompany.com" style name
You can specify any of the properties on the UserPrincipal and use those as "query-by-example" for your PrincipalSearcher.
Your current code is on the right track.
I think you had your wildcard backwards.
Consider this:
search.Filter = string.Format("(&(sn={0}*)(givenName={1}*)(objectSid=*))", lastName, firstName);

RavenDB IsOperationAllowedOnDocument not supported in Embedded Mode

RavenDB throws InvalidOperationException when IsOperationAllowedOnDocument is called using embedded mode.
I can see in the IsOperationAllowedOnDocument implementation a clause checking for calls in embedded mode.
namespace Raven.Client.Authorization
{
public static class AuthorizationClientExtensions
{
public static OperationAllowedResult[] IsOperationAllowedOnDocument(this ISyncAdvancedSessionOperation session, string userId, string operation, params string[] documentIds)
{
var serverClient = session.DatabaseCommands as ServerClient;
if (serverClient == null)
throw new InvalidOperationException("Cannot get whatever operation is allowed on document in embedded mode.");
Is there a workaround for this other than not using embedded mode?
Thanks for your time.
I encountered the same situation while writing some unit tests. The solution James provided worked; however, it resulted in having one code path for the unit test and another path for the production code, which defeated the purpose of the unit test. We were able to create a second document store and connect it to the first document store which allowed us to then access the authorization extension methods successfully. While this solution would probably not be good for production code (because creating Document Stores is expensive) it works nicely for unit tests. Here is a code sample:
using (var documentStore = new EmbeddableDocumentStore
{ RunInMemory = true,
UseEmbeddedHttpServer = true,
Configuration = {Port = EmbeddedModePort} })
{
documentStore.Initialize();
var url = documentStore.Configuration.ServerUrl;
using (var docStoreHttp = new DocumentStore {Url = url})
{
docStoreHttp.Initialize();
using (var session = docStoreHttp.OpenSession())
{
// now you can run code like:
// session.GetAuthorizationFor(),
// session.SetAuthorizationFor(),
// session.Advanced.IsOperationAllowedOnDocument(),
// etc...
}
}
}
There are couple of other items that should be mentioned:
The first document store needs to be run with the UseEmbeddedHttpServer set to true so that the second one can access it.
I created a constant for the Port so it would be used consistently and ensure use of a non reserved port.
I encountered this as well. Looking at the source, there's no way to do that operation as written. Not sure if there's some intrinsic reason why since I could easily replicate the functionality in my app by making a http request directly for the same info:
HttpClient http = new HttpClient();
http.BaseAddress = new Uri("http://localhost:8080");
var url = new StringBuilder("/authorization/IsAllowed/")
.Append(Uri.EscapeUriString(userid))
.Append("?operation=")
.Append(Uri.EscapeUriString(operation)
.Append("&id=").Append(Uri.EscapeUriString(entityid));
http.GetStringAsync(url.ToString()).ContinueWith((response) =>
{
var results = _session.Advanced.DocumentStore.Conventions.CreateSerializer()
.Deserialize<OperationAllowedResult[]>(
new RavenJTokenReader(RavenJToken.Parse(response.Result)));
}).Wait();

how to get authenticated user id from wcf in nhibernate

I have implemented NHibernate custom context (ICurrentSessionContext).
In this context I inject the NHibernate session so I have Session per call pattern setup.
Ok, now I have made an interceptor that takes userId of the current logged user.
Now I do this:
public ISession CurrentSession()
{
// Get the WCF InstanceContext:
var contextManager = OperationContext.Current.InstanceContext.Extensions.Find<NHibernateContextManager>();
if (contextManager == null)
{
throw new InvalidOperationException(
#"There is no context manager available.
Check whether the NHibernateContextManager is added as InstanceContext extension.
Make sure the service is being created with the NhServiceHostFactory.
This Session Provider is intended only for WCF services.");
}
var session = contextManager.Session;
AuditLogInterceptor interceptor = new AuditLogInterceptor();
if (session == null)
{
session = this._factory.OpenSession(interceptor);
interceptor.Session = session;
contextManager.Session = session;
}
return contextManager.Session;
}
My AuditLogInterceptor takes UserId but I don't know how (from where) to get this userId.
If your user is authenticated you can use:
OperationContext.Current.ServiceSecurityContext.PrimaryIdentity.Name
I assume that the current user is being set as the principal on the current thread?
If so, something like this is what you need:
var userName = Thread.CurrentPrincipal.Identity.Name;
There is some additional information in this article that may prove helpful.