How do I use projections in Embedded mode

EventStoreDB
1

I’m running embedded mode for integration testing. I can append events and subscribe to individual streams. However, I can’t subscribe to a category stream. I get an AccessDeniedException: Read access denied for stream ‘$ce-test’.

I have enabled projections:

EmbeddedVNodeBuilder.AsSingleNode().RunProjections(ProjectionsMode.All).StartStandardProjections()

.OnDefaultEndpoints().RunInMemory().Build()

``

I’ve also tried explicitly passing user credentials or as default on the connection setting, but then I get an Authentication Error. What am I doing wrong?

2

Hi Jonathan,
I have actually been playing with that very same scenario and just so happen to have a bit of code to share with you.

Let me know if this works for you?

public class Program

{

public static void Main()

{

var eventStore = StartEmbeddedEventStore();

var defaultCredentials = new UserCredentials(“admin”, “changeit”);

var connectionSettings = ConnectionSettings.Create()

.SetDefaultUserCredentials(null) //replace with

//.SetDefaultUserCredentials(defaultCredentials)

.KeepReconnecting();

using (var connection = EmbeddedEventStoreConnection.Create(eventStore, connectionSettings))

{

connection.ConnectAsync().Wait();

var sub = connection.SubscribeToStreamFrom("$ce-test", null, true,

(_, evt) => Console.WriteLine(“Event Appeared: {0}”, evt.Event.EventType),

subscriptionDropped: (_, reason, e) => Console.WriteLine(“Subscription Dropped, Reason : {0}/{1}”, reason, e.InnerException.Message),

userCredentials: null);

//userCredentials: defaultCredentials);

connection.AppendToStreamAsync(“test-account”,

ExpectedVersion.Any,

GetEventDataFor(100)).Wait();

Console.WriteLine("-------------------------------");

Console.WriteLine(“Embedded Event Store is now running with Projections Enabled.”);

Console.WriteLine(“You are able to issue a curl request to http://localhost:2113/stats as well as http://localhost:2113/projections/any”);

Console.WriteLine();

Console.WriteLine(“Press any key to kill the node.”);

Console.WriteLine("-------------------------------");

Console.ReadLine();

sub.Stop();

connection.Close();

}

eventStore.Stop();

}

static ClusterVNode StartEmbeddedEventStore()

{

var embeddedEventStore = EmbeddedVNodeBuilder.AsSingleNode()

.RunInMemory()

.RunProjections(ProjectionsMode.All)

.OnDefaultEndpoints()

.StartStandardProjections()

.AddExternalHttpPrefix(“http://*:2113/”)

.Build();

var startedEvent = new ManualResetEventSlim(false);

embeddedEventStore.MainBus.Subscribe(

new AdHocHandler<UserManagementMessage.UserManagementServiceInitialized>(m => startedEvent.Set()));

embeddedEventStore.Start();

if (!startedEvent.Wait(60000))

throw new TimeoutException(“Embedded Event Store has not started in 60 seconds.”);

return embeddedEventStore;

}

private static EventData GetEventDataFor(int i)

{

return new EventData(

Guid.NewGuid(),

“DepositMade”,

true,

Encoding.ASCII.GetBytes("{“somedata” : " + i + “}”),

Encoding.ASCII.GetBytes("{“metadata” : " + i + “}”)

);

}

}

``

3

Thanks for the code, but I get a similar error when running this:

Subscription Dropped, Reason : CatchUpError/Read access denied for stream ‘$ce-test’

``

4

or did you replace userCredentials: null with userCredentials: defaultCredentials in the subscription call?

For the default user credentials to work in the connection settings, you have to be using the latest Client which is 3.3.1

5

Ah, ok. Yes now it works. Thanks. I can’t immediately see what you are doing differently. I will investigated.

6

OK, when I add this part, it works:

var startedEvent = new ManualResetEventSlim(false);

embeddedEventStore.MainBus.Subscribe(new AdHocHandler<UserManagementMessage.UserManagementServiceInitialized>(m => startedEvent.Set()));
embeddedEventStore.Start();

if (!startedEvent.Wait(60000))

throw new TimeoutException("Embedded Event Store has not started in 60 seconds.")

``

I was using:

let nodeTcs = TaskCompletionSource()

clusterVNode.NodeStatusChanged.Add(fun x -> if x.NewVNodeState.Equals(VNodeState.Master) then nodeTcs.SetResult(true))

clusterVNode.Start()

``

It’s probably not quite ready at that point. Thanks a lot!