Firestore Emulator fails to start when run inside Docker

ra9r :

I am running a docker image based on alpine that has nodejs and openjdk8 installed. After I successfully install firebase-tools via npm and I try to start the firestore emulator using this command:

firebase serve --only firestore

I get the following error:

    ⚠  firestore: Exception in thread "main"
    ⚠  firestore: java.io.IOException: Failed to bind

    ⚠  firestore:   at io.grpc.netty.NettyServer.start(NettyServer.java:256)
            at io.grpc.internal.ServerImpl.start(ServerImpl.java:167)
            at io.grpc.internal.ServerImpl.start(ServerImpl.java:81)
            at io.gapi.emulators.grpc.GrpcServer.start(GrpcServer.java:151)
            at com.google.cloud.datastore.emulator.firestore.CloudFirestore.main(CloudFirestore.java:69)
    Caused by: java.net.SocketException: Protocol family unavailable
            at sun.nio.ch.Net.bind0(Native Method)
            at sun.nio.ch.Net.bind(Net.java:433)
            at sun.nio.ch.Net.bind(Net.java:425)
            at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)

    ⚠  firestore:   at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:130)
            at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:562)
            at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1358)
            at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:501)
            at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:486)
            at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:1019)
            at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:258)
            at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:366)
            at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)

    ⚠  firestore:   at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
            at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:474)
            at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)
            at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
            at java.lang.Thread.run(Thread.java:748)

I tried setting the JAVA_OPTS as follows:

export JAVA_OPTS="-Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Addresses=true"

But I still get a similar error:

    ⚠  firestore: Exception in thread "main"
    ⚠  firestore: java.io.IOException: Failed to bind
            at io.grpc.netty.NettyServer.start(NettyServer.java:256)
            at io.grpc.internal.ServerImpl.start(ServerImpl.java:167)
            at io.grpc.internal.ServerImpl.start(ServerImpl.java:81)
            at io.gapi.emulators.grpc.GrpcServer.start(GrpcServer.java:151)
            at com.google.cloud.datastore.emulator.firestore.CloudFirestore.main(CloudFirestore.java:69)
    Caused by: java.net.SocketException: Protocol family unavailable
            at sun.nio.ch.Net.bind0(Native Method)
            at sun.nio.ch.Net.bind(Net.java:433)
            at sun.nio.ch.Net.bind(Net.java:425)
            at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
            at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:130)
            at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:562)
            at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1358)
            at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:501)
            at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:486)
            at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:1019)
            at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:258)
            at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:366)
            at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
            at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
            at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:474)
            at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)
            at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
            at java.lang.Thread.run(Thread.java:748)

Has anyone seen this error and found a solution?

ra9r :

The solution is simple, though I must admit doesn't make much sense, is to run the JAR directly and not start it via the firebase tool.

java -jar $HOME/.cache/firebase/emulators/cloud-firestore-emulator-v1.3.0.jar --host=127.0.0.1