Can't get docker to accept request over the internet - linux

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.

Related

Docker cannot access mariadb server

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.

"The connection was reset" after starting my server [duplicate]

I'm running a webpack-dev-server application inside a Docker container (node:4.2.1). If I try to connect to the server port from within the container - it works fine. However, trying to connect it from the host computer results in reset connection (the port is published, of course). How can I fix it?
This issue is not a docker problem.
Add --host=0.0.0.0 to your webpack command.
You need to connect to your page like this:
http://host:port/webpack-dev-server/index.html
Look to the iframe mode
You need to make sure:
you docker container has mapped the EXPOSE'd port to a host port
docker run -p x:y
your VM (if you are using docker machine with a VM) has forwarded that mapped port to the actual host (the host of the VM).
See "How to access tomcat running in docker container from browser?"

Exposing node Server running on docker doesn't work

I am running a angular app on node server and in server.js I have specified app.listen(8084,localhost)..So when i run npm start in the docker container and try to -p 8084:8084 in docker run I was not able to get anything, even though the curl command inside my container curl localhost:8084 was giving me right result.
So i change the app.listen(8084) and the -p 8084:8084 started working..I am not sure why ?
When you open socket, you need to bind it to some interface in your system. There are predefined values:
0.0.0.0 - all interfaces, your service will be available from any interface
locahost, 127.0.0.1 - bind locally. That means service is NOT available from oustide -- this is your case.
You also can specify particular interface IP address to bind to it.
When you start your container, by default docker start default bridge network, so your container is being put into separate network and to access it, you need to allow incoming remote connections in container.
You bind your service to localhost into a container, so no communication is possible outside the container. localhost for your node server is not the same than localhost for your container.

Connecting to a Docker container using domain name from the same physical location

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.

Web service under Docker connection issue

I'm having some troubles running Apache under Docker, and I wanted to ask for some directions. My current setup is the following : I have Docker 0.8 installed on an Ubuntu 12.04 server.
I want to run an Apache server under Docker, and bind it to a specific ip on the host, my intention being to run multiple Apache servers under Docker on the same hardware node each with it's one interface.
Now, I've been able to start the Apache server inside Docker, and have it run like a daemon (-D FOREGROUND, or under supervisord), and I've even been able to bind it to 0.0.0.0:$PORT and access it from the outside. But when I created multiple interfaces on the hardware node let's say 10.10.10.1, and 10.10.10.2, and tried to bind to -p 10.10.10.1:80:80, I'm not able to access 10.10.10.1:80 from the outside.
A little info about the network setup: I have my eth0 interface which has trunking out of which I create multiple vlans on which I want to put Docker instances (probably with a bridge on the eth0.$VLAN_NO, when I want to put more on the same vlan).
So basically, to reiterate, i have started a Docker container bound with -p 10.10.10.1:80:80, with an Apache inside Docker on port 80 and I can't access it (although binded on 0.0.0.0:80:80 works).

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