Description

On Alpine Linux with .NET Core 2.1 and installed librdkafka consumer’s .ctor raises following exception:

Unhandled Exception: System.InvalidOperationException: Failed to create thread: No error information (0)
   at Confluent.Kafka.Impl.SafeKafkaHandle.Create(RdKafkaType type, IntPtr config)
   at Confluent.Kafka.Consumer..ctor(IEnumerable`1 config)
   at Confluent.Kafka.Consumer`2..ctor(IEnumerable`1 config, IDeserializer`1 keyDeserializer, IDeserializer`1 valueDeserializer)
   at app.Program.Main(String[] args) in /app/Program.cs:line 9

Without installed librdkafka I get following exception:

Unhandled Exception: System.DllNotFoundException: Failed to load the librdkafka native library.
   at Confluent.Kafka.Impl.LibRdKafka.Initialize(String userSpecifiedPath)
   at Confluent.Kafka.Consumer..ctor(IEnumerable`1 config)
   at Confluent.Kafka.Consumer`2..ctor(IEnumerable`1 config, IDeserializer`1 keyDeserializer, IDeserializer`1 valueDeserializer)
   at app.Program.Main(String[] args) in /app/Program.cs:line 9

How to reproduce

1. docker build --tag repro-image . with following Dockerfile:

FROM microsoft/dotnet:2.1.301-sdk-alpine3.7

WORKDIR /app

# Install requirements
RUN apk add --update \
        bash \
        git \
        make \
        gcc \
        g++

# Build librdkafka from source
RUN git clone https://github.com/edenhill/librdkafka.git /librdkafka \
    && cd /librdkafka \
    && git checkout v0.11.4 \
    && ./configure \
    && make \
    && make install

# Create .NET Core console app
RUN cd /app \
    && dotnet new console \
    && dotnet add package -v 0.11.4 Confluent.Kafka

1. docker run -it repro-image
2. Fill Program.cs:

namespace app
{
    class Program
    {
        static void Main(string[] args)
        {
            var loaded = Confluent.Kafka.Library.Load("/usr/local/lib/librdkafka.so");
            System.Console.WriteLine("Library is loaded: " + loaded.ToString());
            var consumer = new Confluent.Kafka.Consumer<string, string>(
                new System.Collections.Generic.Dictionary<string, object>{{ "group.id", "test" }, { "debug", "all" }},
                new Confluent.Kafka.Serialization.StringDeserializer(System.Text.Encoding.UTF8),
                new Confluent.Kafka.Serialization.StringDeserializer(System.Text.Encoding.UTF8));
        }
    }
}

1. dotnet run

Checklist

Please provide the following information:

• Confluent.Kafka nuget version: 0.11.4
• Operating system: Alpine Linux 3.7
• Apache Kafka version:
• Client configuration:
• Provide logs (with “debug” : “…” as necessary in configuration)
• Provide broker log excerpts
• Critical issue