CODEWITHSUNDEEP
azure-service-fabric
BrettRobi
BrettRobi

Reputation: 3921

Publicly exposing a WCF restful service via http from Service Fabric

I am trying to expose a WCF based restful service via http and am so far unsuccessful. I'm trying on my local machine first so prove it works. I found a suggestion here that I remove my local cluster and then manually run this powershell command from the SF SDK folder as administrator to recreate it with the machine name binding: .\DevClusterSetup.ps1 -UseMachineName

It created the cluster successfully. I can use the SF Explorer and see in the cluster manifest that entries in the NodeList show the machine name rather than localhost. This seems good.

But the first problem I notice is that if I expand my way through SF Explorer down to the node my app is running on I see an endpoints entry but the URL is not what I'd expect. I am seeing this: http://surfacelap/d5be9425-3247-4290-b77f-1a90f728fb8d/39cda0f7-cef4-4c7f-8af2-d05786a834b0-131111019607641260

Is that what I should see even though I have an endpoint setup? I did not expect the guid and other numbers in the path. This makes me suspect that SF is not seeing my service as being publicly accessible and instead is maybe only setup for internal access within the app? If I dig down into my service manifest I see this as expected:

<Resources>
    <Endpoints>
      <Endpoint Name="ResolverEndpoint" Protocol="http" Type="Input" Port="80" />
    </Endpoints>
</Resources>

But how do I know if the service itself is mapped to it? When I use the crazy long url above and try a simple method of my service I get an http 202 response and no response data as expected. If I then change the method name to one that doesn't exist I get the same thing, not the expected http 404. I've tried using both my machine name and localhost. Same result.

So clearly I'm doing something wrong. Below is my CreateServiceInstanceListeners override. In it you can see I use "ResolverEndpoint" as my endpoint resource name, which matches the service manifest:

    protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
    {
        return new[] { new ServiceInstanceListener((context) =>
            new WcfCommunicationListener<IResolverV2>(
                serviceContext: context,
                wcfServiceObject: new ResolverServiceV2(),
                listenerBinding: new WebHttpBinding(WebHttpSecurityMode.None),
                endpointResourceName: "ResolverEndpoint"
            )
        )};
    }

What am I doing wrong here?

Upvotes: 1

Views: 446

Answers (2)

LoekD
LoekD

Reputation: 11470

Here's a way to get it to work: https://github.com/loekd/ServiceFabric.WcfCalc

Essential changes to your code are the use of the public name of your cluster as endpoint URL and an additional WebHttpBehavior behavior on that endpoint.

Upvotes: 1

VipulM-MSFT
VipulM-MSFT

Reputation: 476

The endpoint resources specified in the service manifest is shared by all of the replica listeners in the process that use the same endpoint resource name. So if your service has more than one partition it is possible that more than one replica from different partition may end up in the same process. In order to differentiate the messages addressed to different partitions, the listener adds partition ID and additional instance GUID to the path.

If you are going to have a singleton partition service and know that there will not be more than one replicas in the same process you can directly supply EndpointAddress you want to the listener to open at. Use the CodePackageActivationContext API to get the port from the endpoint resource name, node name or IP address from the NodeContext and then provide the path you want the listener to open at.

Here is the code in the WcfCommunicationListener that constructs the Listen Address. 

  private static Uri GetListenAddress(
        ServiceContext serviceContext,
        string scheme,
        int port)
    {
        return new Uri(
            string.Format(
                CultureInfo.InvariantCulture,
                "{0}://{1}:{2}/{5}/{3}-{4}",
                scheme,
                serviceContext.NodeContext.IPAddressOrFQDN,
                port,
                serviceContext.PartitionId,
                serviceContext.ReplicaOrInstanceId,
                Guid.NewGuid()));
    }

Please note that you can now have only once application, one service and one partition on a node and when you are testing locally, keep the instance count of that service as 1. When deployed in the actual cluster you can use -1 instance count.

Upvotes: 1

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