can't connect to docker container from outside

Question

Hi i have a image created by below Dockerfile

# This dockerfile uses the gabrielwu/metinvest image

# Base image to use, this must be set as the first line
FROM gabrielwu/mongodb:v0.01

# Maintainer: docker_user <docker_user at email.com> (@docker_user)
MAINTAINER gabrielwu 

EXPOSE 27017
EXPOSE 28017

# Commands to update the image


# Commands when creating a new container
#CMD ["-f /home/mongodir/conf/mongod.conf"]

ENTRYPOINT mongod -f /home/mongodir/conf/mongod.conf

And i created a container based on above image. below are commands i used to create the container. And i tried to connect it from outside with mongo client. It said connection refused.

1010deiMac:metinvest whoami$ docker run -d -p 127.0.0.1:27017:27017 -p 127.0.0.1:28017:28017 gabrielwu/mongodb:v0.02 
4c6352575be95c0162a9603ed702d51a8cadcca505c7744b6fac19b84b33a920
1010deiMac:metinvest whoami$ mong
-bash: mong: command not found
1010deiMac:metinvest whoami$ mongo
MongoDB shell version: 3.0.6
connecting to: test
2016-09-15T21:37:51.831+0800 W NETWORK  Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused
2016-09-15T21:37:51.833+0800 E QUERY    Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed
    at connect (src/mongo/shell/mongo.js:179:14)
    at (connect):1:6 at src/mongo/shell/mongo.js:179
exception: connect failed
1010deiMac:metinvest whoami$

Also this is logs i see for the container. You can see mongodb is running pretty within container.

1010deiMac:metinvest whoami$ docker logs 4c6352575be95c0162a9603ed702d51a8cadcca505c7744b6fac19b84b33a920
Thu Sep 15 13:22:29.694 [initandlisten] MongoDB starting : pid=5 port=27017 dbpath=/home/mongodir/data 64-bit host=4c6352575be9
Thu Sep 15 13:22:29.694 [initandlisten] db version v2.4.9
Thu Sep 15 13:22:29.695 [initandlisten] git version: nogitversion
Thu Sep 15 13:22:29.695 [initandlisten] build info: Linux orlo 3.2.0-58-generic #88-Ubuntu SMP Tue Dec 3 17:37:58 UTC 2013 x86_64 BOOST_LIB_VERSION=1_54
Thu Sep 15 13:22:29.695 [initandlisten] allocator: tcmalloc
Thu Sep 15 13:22:29.695 [initandlisten] options: { config: "/home/mongodir/conf/mongod.conf", dbpath: "/home/mongodir/data" }
Thu Sep 15 13:22:29.699 [initandlisten] journal dir=/home/mongodir/data/journal
Thu Sep 15 13:22:29.700 [initandlisten] recover : no journal files present, no recovery needed
Thu Sep 15 13:22:30.221 [initandlisten] preallocateIsFaster=true 10.02
Thu Sep 15 13:22:30.373 [initandlisten] preallocateIsFaster=true 2.58
Thu Sep 15 13:22:31.492 [FileAllocator] allocating new datafile /home/mongodir/data/local.ns, filling with zeroes...
Thu Sep 15 13:22:31.492 [FileAllocator] creating directory /home/mongodir/data/_tmp
Thu Sep 15 13:22:31.497 [FileAllocator] done allocating datafile /home/mongodir/data/local.ns, size: 16MB,  took 0.002 secs
Thu Sep 15 13:22:31.497 [FileAllocator] allocating new datafile /home/mongodir/data/local.0, filling with zeroes...
Thu Sep 15 13:22:31.500 [FileAllocator] done allocating datafile /home/mongodir/data/local.0, size: 64MB,  took 0.002 secs
Thu Sep 15 13:22:31.501 [initandlisten] waiting for connections on port 27017
Thu Sep 15 13:22:31.501 [websvr] admin web console waiting for connections on port 28017

And i also checked with docker ps.

1010deiMac:metinvest whoami$ docker ps
CONTAINER ID        IMAGE                     COMMAND                  CREATED             STATUS              PORTS                                                    NAMES
4c6352575be9        gabrielwu/mongodb:v0.02   "/bin/sh -c 'mongod -"   30 minutes ago      Up 14 minutes       127.0.0.1:27017->27017/tcp, 127.0.0.1:28017->28017/tcp   cocky_mestorf

Now i'm totally lost why i couldn't connect to it from outside.

--------------------------Edit--------------------------------------

Now i removed the 127.0.0.1 when creating container and tried again. it ended failure as well.

1010deiMac:metinvest whoami$ docker run -d -p 27017:27017 -p 28017:28017 gabrielwu/mongodb:v0.02
3eb14d204370867cab18ed26a55ecb42719772852c691c5163d6906cbbb6a329
1010deiMac:metinvest whoami$ docker ps
CONTAINER ID        IMAGE                     COMMAND                  CREATED             STATUS              PORTS                                                NAMES
3eb14d204370        gabrielwu/mongodb:v0.02   "/bin/sh -c 'mongod -"   9 seconds ago       Up 10 seconds       0.0.0.0:27017->27017/tcp, 0.0.0.0:28017->28017/tcp   lonely_khorana
1010deiMac:metinvest whoami$ mongo
MongoDB shell version: 3.0.6
connecting to: test
2016-09-15T22:57:07.713+0800 W NETWORK  Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused
2016-09-15T22:57:07.715+0800 E QUERY    Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed
    at connect (src/mongo/shell/mongo.js:179:14)
    at (connect):1:6 at src/mongo/shell/mongo.js:179
exception: connect failed
1010deiMac:metinvest whoami$

----------------------------Edit Update ------------------------

I tried it with ip from machine still can't work:

1010deiMac:metinvest whoami$ docker-machine env
export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.100:2376"
export DOCKER_CERT_PATH="/Users/whoami/.docker/machine/machines/default"
export DOCKER_MACHINE_NAME="default"
# Run this command to configure your shell: 
# eval $(docker-machine env)

And

1010deiMac:metinvest whoami$ docker run -d -p 192.168.99.100:27017:27017 -p 192.168.99.100:28017:28017 gabrielwu/mongodb:v0.02
259cd941be6a005f2dcaf9474625fc423a1ba408d6321e56b5c0f517999abe62

And

1010deiMac:metinvest whoami$ mongo
MongoDB shell version: 3.0.6
connecting to: test
2016-09-15T23:40:33.170+0800 W NETWORK  Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused
2016-09-15T23:40:33.172+0800 E QUERY    Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed
    at connect (src/mongo/shell/mongo.js:179:14)
    at (connect):1:6 at src/mongo/shell/mongo.js:179
exception: connect failed

Which version of Docker and which version of OS are you using? — Xiongbing Jin, Sep 15 '16 at 14:30
1010deiMac:~ whoami$ docker -v Docker version 1.12.1, build 23cf638 — Gabriel Wu, Sep 15 '16 at 14:39
Can you remove `127.0.0.1` in your `docker run` command and try again. I think just the port mapping is enough. No need for IP there. — Xiongbing Jin, Sep 15 '16 at 14:55
HI i tried and you can see my edit section above. it still couldn't work :( so sad — Gabriel Wu, Sep 15 '16 at 14:59
Are you using "docker for mac" or "docker toolbox". The IP is wrong. Docker is running in a VM, so you have to either use the IP of the VM, or make sure it's configured to forward the port. — dnephin, Sep 15 '16 at 15:11
I guess so. i used docker toolbox to create my docker enviroment on my Mac. Where can i find the ip of the VM ? sorry i'm new to docker — Gabriel Wu, Sep 15 '16 at 15:15
I never know there's a difference when using docker toolbox from regular way to do docker port forwarding — Gabriel Wu, Sep 15 '16 at 15:17
Execute `docker-machine ls` to obtain your docker container IP if your are using `boot2docker`. — mkorszun, Sep 15 '16 at 15:43
@mkorszun i'm using docker toolbox i think 1010deiMac:metinvest whoami$ docker-machine ls NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS default * virtualbox Running tcp://192.168.99.100:2376 v1.12.1 — Gabriel Wu, Sep 15 '16 at 15:47
@dnephin what is supposed to be the IP here ? i found the ip in container 172.17.0.2 but i'm not sure it's the ip i should be looking for — Gabriel Wu, Sep 15 '16 at 15:50

score 1 · Accepted Answer · edited May 23 '17 at 12:00

The problem i couldn't connect to my localhost host of PC to the container is because container is running in VM !!!

Here are some articles i love to share regarding this issue: Accessing docker containers on localhost when using Boot2Docker

port forwarding in docker machine

The tricky thing is to understand container is running in a vm so when expose a port of container it's actually mapping to the port in vm, not port in my PC localhost.

Here is how to fix the problem. 1: map ports of vm to localhost. See how to use this command, please refer to VBoxManage controlvm

VBoxManage controlvm default natpf1 "tcp-port27017,tcp,127.0.0.1,27017,,27017"
VBoxManage controlvm default natpf1 "tcp-port28017,tcp,127.0.0.1,28017,,28017"

you also may need to query if the mappings are added, or you want to further check, check this LIST natpf rules in Virtualbox/Vagrant

Well i prefer to use showvminfo to check mappings. You can find your mappings in its output.

VBoxManage showvminfo default

then start up your container, and test with mongo client:

1010deiMac:metinvest whoami$ docker run -d -p 27017:27017 -p 28017:28017 gabrielwu/mongodb:v0.02
94d1a4639d662b3ec04a2f363efb984b2d1ff9c4df1db1026d6c94f86013de26
1010deiMac:metinvest whoami$ mongo
MongoDB shell version: 3.0.6
connecting to: test
>

it works.

I was surprised by this behaviour as well. It would be nice if `docker for mac` came with clear warnings around these issues. — shusson, Sep 16 '16 at 04:45
@shusson yep i feel the same way. i followed a docker starter tutorial and ended up with this problem . if there's some warning or notification around it, for newbies like me, i would save me lots of time — Gabriel Wu, Sep 16 '16 at 08:24

can't connect to docker container from outside

1 Answers1