无法使用MongoJavaDriver连接到mongodb容器

Question

I can across this problem and found multiple people online with the same issue.

I had been trying:

new MongoClient(new ServerAddress("0.0.0.0", 27017), mongoClientBuilder.build());

I also tried "localhost" and "127.0.0.1" with no luck. The issues raised online had the same stack trace:

    INFO: Exception in monitor thread while connecting to server localhost:27017
com.mongodb.MongoSocketOpenException: Exception opening socket
    at com.mongodb.connection.SocketStream.open(SocketStream.java:63)
    at com.mongodb.connection.InternalStreamConnection.open(InternalStreamConnection.java:114)
    at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:128)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: Connection refused
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at com.mongodb.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:50)
    at com.mongodb.connection.SocketStream.open(SocketStream.java:58)
    ... 3 more

Answer 1

You need to expose the port to the docker container when you create it:

docker pull mongo
docker run --name mongo -d -p 27017:27017 mongo

and then you can connect to localhost port 27017

Answer 2

First you need the container id:

docker ps

You need to get the specific ip for the container:

$ docker exec -it ${container_id} bash

This will open a terminal session within your container. Next run (in the container terminal):

$ cat /etc/hosts

This will print out the hosts, including an entry where the name is the first few characters of the container id.

The output will look something like this:

127.0.0.1   localhost
...
...
172.17.0.2  container_id

The IP next to your container id is what you want to use:

new MongoClient(new ServerAddress("172.17.0.2", 27017), mongoClientBuilder.build());

If anyone has a more elegant solution I would be interested to hear it. For example this ip may change, though in my experience it doesn't when the container restarts.