I run docker container docker run -it --network host ubuntu:latest bash, but when I start there some server(on port 3000 for example), i can not open it from the main os.
How can I start the container (without describing expose or publish port) for up there some servers on different ports dynamicaly, and i want that ports will be available from the outer. I want to create container once, and keep there all changes, and back there via command docker start ..., docker exec ...
Visit this link to your solution
Here's Docker networking in the section The Host Driver
You will find the following abstract
As the name suggests, host drivers use the networking provided by the host machine. And it removes network isolation between the container and the host machine where Docker is running. For example, If you run a container that binds to port 80 and uses host networking, the container’s application is available on port 80 on the host’s IP address. You can use the host network if you don’t want to rely on Docker’s networking but instead rely on the host machine networking.
One limitation with the host driver is that it doesn’t work on Docker desktop: you need a Linux host to use it. This article focuses on Docker desktop, but I’ll show you the commands required to work with the Linux host.
The following command will start an Ubuntu image and listen to port 80 on the host machine:
docker run -it --network host ubuntu:latest /bin/bash
Related
I am trying to connect and run a device (LiDAR) through Docker container since it needs Ubuntu 16 while my computer is Ubunutu 20.
I got the device to ping inside the docker container, but it is not recognised when I try to use it.
What I did:
Made Dockerfile with requirements (Added EXPOSE to expose all ports)
Built docker image using:
docker build -t testLidar
I then made a container using
docker run -d -P --name test_Lidar (imagename)
Then
docker exec -t test_Lidar (device_ip) works
I am able to ping my LiDAR IP inside the container, but when I do ip a I cannot see the interfaces connected to my machine.
Been stuck on this for 3 days, any suggestions?
Note: I have done the exact same steps but on an Ubuntu 16 machine. The only change was the docker run command had --net host instead of -P tag and my device worked perfectly. I feel like this is the root of my problem.
Use --net host flag with docker run to attach the container to your host's networking stack and make it available in for other hosts in your network.
When you use --net host, you actually attach the container to your host's networking stack. By default, containers are attached to the default network of type bridge and can communicate with each other. You can then reach them only from your host using its ip addresses typically in subnet 172.17.0.0/16.
Using -P actually binds exposed ports from a container with randomly selected free ports on your host. It should be used for exposing network services (eg. web server with port 80), but not for ICMP ping.
I have a basic question about Docker that is probably due to lack of knowledge on my part about networking. The Docker container networking documentation states:
By default, when you create a container, it does not publish any of its ports to the outside world. To make a port available to services outside of Docker, or to Docker containers which are not connected to the container’s network, use the --publish or -p flag. This creates a firewall rule which maps a container port to a port on the Docker host.
It sounds like, when you install a container on your computer without mapping any ports from the container to the host machine, the container should not be able to access the internet. However, for example, I install the Ubuntu container with:
docker pull ubuntu
Then I enter the container's command line with:
docker run -ti ubuntu bash
At that point, I can run apt-get update and the container starts pulling information from the internet without mapping any ports (e.g. -p 80:80). How is this possible?
Publishing a port allows machines external to the docker host to access the container, inbound connectivity. By default, containers can access the network with outbound connectivity.
To restrict a container from accessing the network, you can either run the container with no network (note: this still creates a loopback interface, and you can later connect it to another network):
docker run --net none ...
Or you can create a network with the --internal option and run containers on that network:
docker network create --internal internal
docker run --net internal ...
The internal network is created without a gateway interface on the bridge network.
When they talk about publishing ports, they mean inbound ports.
Outbound ports work - depending on your network type - see here for more:
https://docs.docker.com/network/
I am troubleshooting a solution in which I am setting up a HA cluster. Although I know the ports needed for the application to perform failover and failback, somehow the dockerized solution is not working. I suspect that there are some ports that I do not know about yet.
Currently, my EXPOSE statement says:
EXPOSE 8080 61616 5672 61613 5445 1883
I also start my docker containers with
docker run --network host -p 8080:8080 -p 61616:61616 -p 5672:5672 -p 61613:61613 -p 5445:5445 -p 1883:1883
But for the sake of troubleshooting, I want to expose ALL ports.
I tried something like:
EXPOSE 1-65535
But this gives an ERROR.
What is the best way I can expose ALL ports of the docker container?
When running using --network host there is no need to map the ports. All the docker container ports will be available since the network host mode makes the container use the host's network stack.
Also the EXPOSE 8080 61616 5672 61613 5445 1883 is not needed. This instruction doesn't do anything. It is just a way to document which ports need to be mapped.
In short, running docker run --network host ... will expose all the container ports.
The host networking driver only works on Linux hosts, and is not supported on Docker Desktop for Mac, Docker Desktop for Windows, or Docker EE for Windows Server.
More information on the Docker documentation portal.
Using host networking will expose almost all the ports just like you're running the application in the host machine. If port flags are used when running in host networking mode, those flags are ignored with a warning
Note: Given that the container does not have its own IP-address when using host mode networking, port-mapping does not take effect, and the -p, --publish, -P, and --publish-all option are ignored, producing a warning instead:
WARNING: Published ports are discarded when using host network mode
Make sure your host is a Linux host because host networking is only supported by Linux hosts.
The host networking driver only works on Linux hosts, and is not supported on Docker Desktop for Mac, Docker Desktop for Windows, or Docker EE for Windows Server.
This is mentioned in Docker documentation it self. View particular Documentation
How to access or connect to a process running on docker on host A from a remote host B
consider a Host A with ip 192.168.0.3 which is running a application on docker on port 3999 .
If i want to access that application from remote machine with IP 192.168.0.4 in same subnet.
To be precise i am running Kafka producer on the server and i am trying to receive using Kafka-console-Consumer.
Use --net=host to run your container and it'll use the host's network stack, then you can connect to the application running inside container like it's running on host directly.
Port mapping, use option -p to map the port inside your container to a port of your host. e.g. docker run -d -p <container port>:<host port> <image>, then you can connect to <host>:<host port> to connect your application inside container
Docker's built-in multi-host network. In early releases the network driver is isolated from docker's core, you have to use 3rd party tools like flannel or weave for multi-host connection, but from release 1.9, it has been merged into docker. You can follow it's guide to set it up.
Hope this is helpful :-)
First you need to bind docker container's port to the Host A:
docker run -d -p 3999:3999 kafka-producer
Then you need to access Host A from Host B using IP:Port
192.168.0.3:3999
I have:
a Windows server on bare metal with Hyper-V
Ubuntu server running in Hyper-V
a Docker container with an NGINX web application running in Ubuntu server
Every time I run a Docker image it gets a new I.P. address on the Docker0 network interface. For production, I don't know how to make the Docker container visible to the external network. I also don't know how to handle the fact that the I.P address changes every time the image is run.
What's the correct way to:
make a Docker container visible to the external network?
handle Docker container I.P. addresses in a repeatable way in production?
When you run your Docker container with docker run, you should use the -p switch to forward ports, for example:
docker run -p 80:80 nginx
This would route port 80 from the Ubuntu server to port 80 within the Nginx container.
You should check the Docker documentation on this at https://docs.docker.com/reference/run/#expose-incoming-ports.
When you have multiple containers and links, you should use EXPOSE in the Dockerfile as documented here: https://docs.docker.com/reference/builder/#expose.