连接到 Docker 容器中的 mongodb

Question

I am trying to deploy my web api to a docker container. I am able to get the service running in docker but anything related to making a database call it falls over. I'm not entirely sure why. Here is my code:

Dockerfile_local

FROM mcr.microsoft.com/dotnet/core/sdk:3.1.302-alpine3.12 as builder
EXPOSE 27017

COPY . .

RUN dotnet publish --configuration Release MembershipApi/MembershipApi.csproj -o /app

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1.8-alpine3.12

WORKDIR /app

COPY --from=builder /app .

CMD ["dotnet", "MembershipApi.dll"]

docker-compose-local.yml

version: "3"
services: 
    test:
        image: mcr.microsoft.com/dotnet/core/sdk:3.1.402-alpine3.12
        depends_on: 
            - membership-api
            - mongo
        entrypoint: ["dotnet","test", "/builds/MembershipApi.IntergrationTests/MembershipApi.IntergrationTests.csproj", "--configuration", "Release"]
        volumes:
            - .:/builds
        
    membership-api:
        build:
            context: .
            dockerfile: Dockerfile_local
        depends_on:
            - mongo
        ports:
            - 9000:80
    mongo:
        image: mongo:4.0.16
        ports:
            - 27017

Error

membership-api_1  | warn: Microsoft.AspNetCore.HttpsPolicy.HttpsRedirectionMiddleware[3]
membership-api_1  |       Failed to determine the https port for redirect.
membership-api_1  | fail: Microsoft.AspNetCore.Server.Kestrel[13]
membership-api_1  |       Connection id "0HM3LNKLS24AA", Request id "0HM3LNKLS24AA:00000002": An unhandled exception was thrown by the application.
membership-api_1  | System.TimeoutException: A timeout occured after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "Automatic", Type : "Unknown", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : 
"Unspecified/localhost:27017" }", EndPoint: "Unspecified/localhost:27017", ReasonChanged: "Heartbeat", State: "Disconnected", ServerVersion: , TopologyVersion: , Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server.
membership-api_1  |  ---> System.Net.Sockets.SocketException (99): Address not available
membership-api_1  |    at System.Net.Sockets.Socket.BeginConnectEx(EndPoint remoteEP, Boolean flowContext, AsyncCallback callback, Object state)
membership-api_1  |    at System.Net.Sockets.Socket.ConnectAsync(EndPoint remoteEP)
membership-api_1  |    at MongoDB.Driver.Core.Connections.TcpStreamFactory.ConnectAsync(Socket socket, EndPoint endPoint, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.Core.Connections.TcpStreamFactory.CreateStreamAsync(EndPoint endPoint, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)
membership-api_1  |    --- End of inner exception stack trace ---
membership-api_1  |    at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelperAsync(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.Core.Servers.ServerMonitor.InitializeConnectionAsync(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.Core.Servers.ServerMonitor.HeartbeatAsync(CancellationToken cancellationToken)", LastHeartbeatTimestamp: "2020-10-21T12:31:43.5254072Z", LastUpdateTimestamp: "2020-10-21T12:31:43.5254077Z" }] }.
membership-api_1  |    at MongoDB.Driver.Core.Clusters.Cluster.ThrowTimeoutException(IServerSelector selector, ClusterDescription description)
membership-api_1  |    at MongoDB.Driver.Core.Clusters.Cluster.WaitForDescriptionChangedHelper.HandleCompletedTask(Task completedTask)
membership-api_1  |    at MongoDB.Driver.Core.Clusters.Cluster.WaitForDescriptionChanged(IServerSelector selector, ClusterDescription description, Task descriptionChangedTask, TimeSpan timeout, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.Core.Clusters.Cluster.SelectServer(IServerSelector selector, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.MongoClient.AreSessionsSupportedAfterServerSelection(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.MongoClient.AreSessionsSupported(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.MongoClient.StartImplicitSession(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.OperationExecutor.StartImplicitSession(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSession[TResult](Func`2 func, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.MongoCollectionImpl`1.FindSync[TProjection](FilterDefinition`1 filter, FindOptions`2 options, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.FindFluent`2.ToCursor(CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.IAsyncCursorSourceExtensions.SingleOrDefault[TDocument](IAsyncCursorSource`1 source, CancellationToken cancellationToken)
membership-api_1  |    at MongoDB.Driver.IFindFluentExtensions.SingleOrDefault[TDocument,TProjection](IFindFluent`2 find, CancellationToken cancellationToken)
membership-api_1  |    at MembershipApi.Data.PaymentRepo.GetBalanceById(Int32 id) in /MembershipApi/Data/PaymentRepo.cs:line 23
membership-api_1  |    at MembershipApi.Controllers.PaymentController.GetBalance(Int32 id) in /MembershipApi/Controllers/PaymentController.cs:line 24
membership-api_1  |    at lambda_method(Closure , Object , Object[] )
membership-api_1  |    at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)     
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
membership-api_1  | --- End of stack trace from previous location where exception was thrown ---
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
membership-api_1  | --- End of stack trace from previous location where exception was thrown ---
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)  
membership-api_1  |    at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
membership-api_1  |    at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
membership-api_1  |    at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
membership-api_1  |    at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

Answer 1

If both your dockerized webserver and your database are in the same docker network, they can't communicate with each other using localhost but with their respective service name.

Eg instead of using

localhost:27017

you must use

mongo:27017

You need to configure this in your dotnet app, after that it will be able to connect to your database in the dockerized setup. Of course you then have to think about cases, where your apps are not running dockerized, eg in local development. You need a configuration mechanism that sets the database url depending on the current environment (dev, docker-prod, etc.).