Using localhost for to access running container

General Discussions General
1

This command below:

docker run --rm -it -p 127.0.0.1:3000:3000 -v $(pwd):/usr/src/app sanchezjjose/my-node-app

Which I am running should apparently allow me to run my application against localhost on port 3000 locally, but instead in Kitematic I see:

'Access URL' : 192.168.99.100:3000

In the docker terminal when running ‘docker ps’ I see:

127.0.0.1:3000->3000/tcp

When I go to the browser, I am not able to access my application either with 192.168.99.100:3000 OR with localhost:3000.

Is there something maybe I am missing in the documentation on why this will not work? This is my current stack:

 - Mac OSX 
 - Docker 1.8.0 
 - Kitematic 0.8.1 
 - VirtualBox 5.0.0

I also don’t have any port forwaring for port 3000 either in VirtualBox because I figured that adding the host on the run command should allow me to skip that, but I have tried with port forwarding as well and it doesn’t work either.

Thank you very much.

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2

Hello,

When you specify 127.0.0.1:3000:3000, you are binding to the docker host’s 127.0.0.1. Since your docker host is in a VM, that’s different from your 127.0.0.1 on your mac.

If you did docker run --rm -it -p 3000:3000 -v $(pwd):/usr/src/app sanchezjjose/my-node-app instead, it would bind to 0.0.0.0 (all interfaces). That would include the 192.168.99.100 IP, and then you’d be able to access it from your host.

/Jeff

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3

Thanks for your response Jeff.

So because I am using OSX, and the docker host is actually on a VM, there is no way for me to access my application via localhost:3000, unless I am actually port forwarding 3000 from my Mac OSX => VirtualBox VM running docker?

4

That is correct-- you could use virtualbox’s port forwarding feature. You would probably have to bind to the NAT interface’s address instead of 127.0.0.1 though: docker run -p 10.0.2.15:3000:3000 (assuming 10.0.2.15 is the IP of your VM’s interface attached to the virtualbox NAT network). The port forwarding feature is tied to that-- virtualbox won’t reach in to the 127.0.0.1 interface in the VM and redirect ports like that.

5

Thank you Jeff, appreciate your response. I have one other general question I posted here, just in case you are able to take a look, no worries if you can’t but your response was very helpful here.

6

Thanks to this post: http://stackoverflow.com/questions/25327012/access-docker-from-external-machine-in-network

I was able to use [homebrew installed] nginx to forward the ports from my containers within vbox (on os x) to my own ip address so that other machines on my network could reach my containers

I replaced the default port 8080 forward in the default nginx.conf with this

server {
listen 8080;

server_name localhost; 

proxy_redirect off;                                                       
proxy_buffering off;                                                      
proxy_set_header Host $host;                                              
proxy_set_header X-Real-IP $remote_addr;                                  
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;              

location / {                                                              
    proxy_pass http://192.168.99.100:8080;                                            
}

}

to be clear: this is a workaround, what I’d like to be able to do is tell Docker Toolbox [vbox] to get an ip address via dhcp on my network – then I’d not have to forward ports around…

7

Cool workaround, thanks for sharing!

8

Hello, I’ve exactly the same question. I’m running docker on my Mac OS and executing my container with without specifying the IP of my host

docker run -i -p 3000:3000
-e “GF_SERVER_ROOT_URL=http://0.0.0.0”
-e "GF_SECURITY_ADMIN_PASSWORD=secret
grafana/grafana

ad10bbb0d7ef grafana/grafana “/run.sh” 7 minutes ago Up 7 minutes 0.0.0.0:3000->3000/tcp grafana

It’s up and running and accessible by VM’s network IP, not my Mac IP:
http://192.168.99.100:3000/login

Please advise, I just need it to be accessible by using my host’s ip.

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9

Hi,

In case someone is having the same issue, I was able to resolve by putting:

-p 3000:3000

in the docker run command, and putting:

-b 0.0.0.0

in my rails server command. Thanks.

10

I’ve found a solution. In my case am using docker-machine which in turns manages docker-machine running in Virtual Box. Simply select your Docker VM in Virtual Box, open settings > Networking > Advanced > Port forwarding.

Create a new entry and enter the details as follows:

  • Name: web
  • Protocol: TCP
  • Host IP: 127.0.0.1
  • Host Port: 80
  • Guest IP:
  • Guest Port: 80

Click OK. No need to restart. You can access your docker app on localhost:80 immediately

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11

Article explains it very well

Troubleshooting Port Forwarding in VirtualBox