I have a simple NodeJS website. I serve it up locally to port 80 via:
npm start
and all is well. I can access the website through the local ip on phones and other devices using the same network, including the computer itself.
However, when I serve to 80 from the docker container running the npm server via
docker run -p 80:80
All seems well when I test the local ip on the host machine itself. But when I try to access it using phones and other devices using same network, I timeout.
I would expect the docker website to work everywhere on the local network, just the same as my non-container npm start command.
Windows Defender Firewall was blocking the connections going to and from the container.
Related
I have a docker container running in localhost:3000
Also, I have a node app running in localhost:8081
Now if I want to make post or get request from localhost:3000 to localhost:8001 its not working at all.
Now if run the service as a binary (not a docker file) on localhost:3000 the same API requests works.
How do I communicate if using docker?
Each container runs on it's own bridge network where localhost means the container itself.
To access the host, you can add the option --add-host=host.docker.internal:host-gateway to the docker run command. Then you can access the host using the host name host.docker.internal. I.e. if you have a REST service on the host, your URL would look something like http://host.docker.internal:8081/my/service/endpoint.
The name host.docker.internal is the common name to use for the host, but you can use any name you like.
You need docker version 20.10 for this to work.
I am newbie on docker.
I want to migrate my nodejs app to docker, and existing database already installed on server (172.17.2.1). I set mariadb host 172.17.2.1 on my nodejs config.
After that, I created an images and run with :
docker run -p 3009:3009 -d my-node
actually its already running, but when I tested to open by browser, I got an error that my app cannot connect to 172.17.2.1 (connecting to database).
I try to create bridge IP (172.17.2.135) and make a same subnet, but still got a same error.
My images on docker inside doesn't know 172.17.2.1 on my LAN.
Please help me,
I use windows 10 environment
You have two options to allow your container to reach an external server:
Run your docker container on your host network:
docker run -p 3009:3009 --network host -d my-node
This way your container will be able to reach anything reachable from your machine
create a network bridge: in this case docker will route the traffic from the container to the external server. the bridge IP can't be your docker machine IP as you tried to do.
I have a situation where node-container can reach mongo-container if it uses mongo-container's name such that Docker translates it to its internal IP (which I think is how it works). They are running at the same Docker host.
However, if developing locally (not on the Docker host server), we reach mongo by giving domain-name:port to the node-container. This configuration works fine both locally (with/without Docker) and at the server, but only without Docker (so npm start "directly").
The Docker containers at the host are connected to a Docker bridge network.
We would like to use the domain-name:port configuration everywhere ideally, so that we don't have to think about the Docker side of things.
I would like to understand what happens in terms of networking. My rough networking understanding thinks this happens:
WORKING SITUATION # SERVER BY SKIPPING DOCKER:
Host[npm start]-->Node[need to check <domain-name:port>]-->DNS server[this is the IP you need]-->Host[Yes my IP + that port leads to mongo-container].
BROKEN SITUATION # SERVER BY USING NODE BEHIND DOCKER:
Host[docker-compose up etc... npm start via node container]-->Node[need to check <domain-name:port>]-->DNS server[Problem here?].
Thanks for any insights.
So, I'm trying to get Jenkins working inside of docker as an exercise to get experience using docker. I have a small linux server, running Ubuntu 14.04 in my house (computer I wasn't using for anything else), and have no issues getting the container to start up, and connect to Jenkins over my local network.
My issue comes in when I try to connect to it from outside of my local network. I have port 8080 forwarded to the serve with the container, and if I run a port checker it says the port is open. However, when I actually try and go to my-ip:8080, I will either get nothing if I started the container just with -p 8080:8080 or "Error: Invalid request or server failed. HTTP_Proxy" if I run it with -p 0.0.0.0:8080:8080.
I wanted to make sure it wasn't jenkins, so I tried getting just a simple hello world flask application to work, and had the exact same issue. Any recommendations? Do I need to add anything extra inside Ubuntu to get it to allow outside connections to go to my containers?
EDIT: I'm also just using the official Jenkins image from docker hub.
If you are running this:
docker run -p 8080:8080 jenkins
Then to connect to jenkins you will have to connect to (in essence you are doing port forwarding):
http://127.0.0.1:8080 or http://localhost:8080
If you are just running this:
docker run jenkins
You can connect to jenkins using the container's IP
http://<containers-ip>:8080
The Dockerfile when the Jenkins container is built already exposes port 8080
The Docker Site has a great amount of information on container networks.
https://docs.docker.com/articles/networking
"By default Docker containers can make connections to the outside world, but the outside world cannot connect to containers."
You will need to provide special options when invoking docker run in order for containers to accept incoming connections.
Use the -P or --publish-all=true|false for containers to accept incoming connections.
The below should allow you to access it from another network:
docker run -P -p 8080:8080 jenkins
if you can connect to Jenkins over local network from a machine different than the one docker is running on but not from outside your local network, then the problem is not docker. In this case the problem is what ever machine who is receiving outside connection (normally your router, modem or ...) does not know to which machine the outside request should be forwarded.
You have to make sure you are forwarding the proper port on your external IP to proper port on the machine which is running Docker. This can be normally done on your internet modem/router.
I am running docker on OSX via boot2docker. I am using docker remotely, via the API.
I create several images of a web server. Docker assigns different IP address to each container, like 172.17.0.61. Each web server is running on port 8080.
Inside VM, I can ping the server on this address.
How can I map these different container IP addresses (from VM) to the same one in VM, but on different port? E.G.
<local.ip>:9001 -> 172.17.0.61:8080
<local.ip>:9002 -> 172.17.0.62:8080
where local.ip may be either ip from boot2docker or anything else.
Possible solution is to define port bindings when creating container and bind each container to a different port. However, I would like to avoid that, since this config becomes part of the container, and only exist because running on OSX. If I do all this above on linux, we would not have this issue.
How to map inner containers to different ports?
Publishing ports is the right solution. You have the same problem whether you're running remotely or locally, just the IP address changes.
For example, say I start the following web servers:
$ docker run -d -p 8000:80 nginx
$ docker run -d -p 8001:80 nginx
From inside the VM (run boot2docker ssh), I can then run curl localhost:8000 or curl localhost:8001 to reach the website. This is the normal way of working with Docker on Linux. From the Mac command line, it becomes curl $(boot2docker ip):8000 because of the VM, but we've not done anything different with regards to starting the web servers because of boot2docker.