I am using Docker desktop, I have a couple of docker containers running using docker-compose and port forwarding. I can access the containers from my mac using localhost. On the second container, I am exposing on different ports. I can see ip addresses are associated to both containers by using docker inspect, but I cannot access using the ip address.
I would like access the container from my local mac by
dns domain
ip address
Any help appreciated.
Thanks
You cannot directly connect to the container-private IP addresses on MacOS. You also can't connect to them using a VM-based Docker implementation like Docker Toolbox or Kubernetes' minikube, or from a different host. Looking up and using these IP addresses, or trying to manually set them, usually isn't a best practice.
Instead you can use the docker run -p option to publish a port from your container to the host. Programs running directly on the host can access the container using localhost as a host name and the published port number. This works on all platforms; on VM-based solutions use the VM's IP address instead of localhost; from a different host, use the Docker host's DNS name or IP address.
Related
I'm looking for a way to access containers that are running on server in our company lan by domain names. By far I only managed to access them by IPs
So the setup is. Docker (for windows) is running on server srv1.ourdomain.com (Windows Server 2019), network for container is configured with l2bridge driver, container's dns name, as specifiedn in run command, is cont1. It is accessible by dns name on the docker host (srv1) and by IP from my machine.
What can I do to access the container by dns name cont1.ourdomain.com from my local machine located in the same lan?
I tried to use proxy (traefik) but it cant rewrite urls in the content, so web applications running inside the container are failing. Bacause of this I can't host multiple web application behind that proxy.
I know that it is possible to map container's port to host port and then it will be accessible from lan through the host name and host port, but applications I'm running are requiring many ports to be mapped (like 8 ports for each container) and with those containers being short-lived developer's environments it will be a hell to find a port pool when running new container.
So again if I can access container and its' ports by IP, is there a way to do the same by DNS name?
UPD1. Container host is a virtual server running on vmware. I tried to follow those recommendations and configure promiscuous mode. Thise doesn't help with dns though.
UPD2. I tried transparent network as well. For some reason DHCP can never assign propper IP and container ends up with autoconfigured ip from 168.x.x.x subnet.
You could create a transparent network and make the container discoverable on the network just like host. However, using host ports is what's recommended.
Did you try PathStrip or PathPrefixStrip with Traefik? That should let you rewrite the URLs for the backend.
I am using docker container for my asp.net core web api application and container is up and running.
Now I am getting docker internal IP address using below command,
docker inspect -f "{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}" d986472784cb and getting the IP address as 172.20.0.2.
Now I am not getting any result when hitting below url in browser
http://172.20.0.2/WeatherForecast, seeing ERR_CONNECTION_TIMED_OUT error.
local address https://localhost:32772/weatherforecast is just working fine.
What could be the issue?
The container-private IP simply doesn't work in a variety of common circumstances:
If you're not calling from the same host, the container-private IP won't be reachable at all
If there is a VM involved at all (Docker Toolbox on Windows, Docker Desktop on Windows or Mac), the container-private IP won't be reachable at all
If you're not on the same Docker-internal network, you might not be able to reach the container-private IP
Since it doesn't work in so many environments, I wouldn't recommend looking up this IP address at all: forget that particular docker inspect command exists. From the browser, use your host's IP address or DNS name (or localhost if the containers and browser are on the same system, but not if Docker Toolbox is involved) and the published port number (docker run -p option, Docker Compose ports: option, the first port number from that pair).
You need the port number in the ip address url. http://172.20.0.2:32772/WeatherForecast
For regular docker containers (say the hello world example), after you run it, it is accessible thought localhost, where you can make a request it through your browser.
But sometimes it seems to access a container you need a special IP address. I'm wondering what's this behavior of docker container networking called and where is it defined/documented.
Let's say my local ip address is 10.0.75.1 (got from Network properties in Windows settings named, vEthernet (DockerNAT)). But in order to connect to a container running I had to use ip address 10.0.75.2. Why is this?
If try to inspect existing docker networks using docker network [cmd], the containers seem to be on different subnets, for example '172.17.0.0/16'
I deployed a demo web API project on port 8086.I am able to run it on my local browser using localhost:8086/api/controllername and also using local machine IP address for example: 192.0.0.0:8086/api/controllername. I tried accessing the URL from another machine on same LAN and I am able to access it.
But now I want to access it from machines on other networks (publicly).
How can I assign a static IP so that I can use the API from any machine irrespective of network? I created a network using below commands
docker network create --driver bridge --subnet 172.18.0.0/16 -- gateway=172.18.0.1 IPStatic
and
docker network connect --ip 172.18.0.2 IPStatic Containerid.
But unable to access the api using 172.18.0.2:8086/api. Am I missing something? I am using asp.net core web api and I am fairly new to Docker.
You always use the host IP address for this, the same way as if you were running the service outside of Docker. The container-private IP addresses are unreachable from other hosts (and on some platforms aren't even reachable from outside Docker on the same host); it's usually wrong to manually set them or to try to look them up.
If it's specifically important that this service have its own IP address, you need to ask your network administrator to assign an additional address to the host. The docker run -p option can bind a service to only specific network interfaces or addresses. On a Linux host I might run
# Assign the alias address
ifconfig eth0:0 192.0.0.2
# Run the service bound to only this interface
docker run -p 192.0.0.2:80:8080 ...
You might need to reconfigure other services to not listen on this new interface. For Docker services you'd use the same docker run -p option to bind to only the host's primary interface and to localhost (127.0.0.1); configuration for non-Docker services is specific to the service.
I would like to deploy multiple applications via docker. Some of them are using the same port.
An alternative port mapping (Port 80->5080) is not an option, so my way to handle the problem is a network bridge which should allow me to assign an ip address from my internal network to each container.
The answer from this post does not work for me
Assign LAN IP address to Docker container different from host's IP address
i am able to assign an ip to the docker container, but it also gets the host ip address so i can not map ports.