Docker container not exposed on network - docker

I am new to docker. I am running it on windows. I am trying to get a container named "ghost" (available from the Docker Hub) to work on a Windows 8.1 machine. While the container starts correctly and supposedly exposes url at http://localhost:2368, when I enter this address nothing happens. The same has happened when trying other containers from the Hub which expose urls.
I tried accessing the container's exposed URL from the IP Address I get from the "docker ip" but it failed too. I also tried running the container with the "--net="bridge"" option, to no avail. I think I'm missing something pretty basic, but I can't for the life of me figure out what. Can someone point me in the right direction?

When you install Docker on Windows that means you most likely installed boot2docker.
boot2docker starts a minimal Linux VM (based on VirtualBox) because Docker requires a Linux kernel to run. The Docker daemon is started on that VM and not on your localhost.
You can determine the VMs IP address by typing boot2docker ip on your command line. The standard boot2docker IP address is 192.168.59.103 if you did not configure something else or have multiple instances of that VM running.
So when you execute docker run --name ghost -p 2368:2368 -d ghost the port 2368 is opened at 192.168.59.103:2368. That is where you need to connect to.
For more information please read the official boot2docker documentation.

You haven't provided the complete 'docker run ...' command you executed, so I'm assuming you ran the one specified in the image's page on Docker Hub (reproduced below).
docker run --name some-ghost -p 8080:2368 -d ghost
The command is mapping Ghost's exposed port inside the container (2368) to port 8080 in your boot2docker VM. The first thing you need to do is run boot2docker ip to find out the IP address of your boot2docker VM. About the port number, you have two options:
Access Ghost via port 8080 (http://BOOT2DOCKER-IP:8080)
Change the port mapping to expose 2368 (-p 2368:2368)

Related

Problem accessing jupyter notebook from Docker Toolbox Container

I just set up a Docker Container with the Docker Toolbox and ran jupyter notebook inside the container using
docker run --name container -v %somedirectory%:%someotherdir% -d -p 127.0.0.1:8888:8888 quay.io/fenicsproject/stable:2017.2.0 'jupyter-notebook --ip=0.0.0.0'
Afterwards I can check the log of the container to see the URL and token that jupyter notebook created.
If I now go ahead and copy the link to my browser, it won't be able to connect to localhost. Accessing 127.0.0.1 does not work either.
Since the Docker Toolbox relies on Virtual Box VMs, I also tried to use the IP address of the VM, in this case 192.168.99.100:2376. According to the Kitematic UI, this is the IP:Port combination that is being published by the docker-machine and indeed this does not lead to a generic connection error. Instead the browser's output is:
Client sent an HTTP request to an HTTPS server.
I don't really know what to do from this point on. What does this "error" mean? Does it even make sense to use the VM's IP address? And most importlanty: what else can I do in order to finally get access to the jupyter notebook?
PS: I also tried the suggestions made in the threads Can't access jupyter notebook from docker and Access Jupyter notebook running on Docker container and couldn't make any of them work unfortunately.
I hope someone can help, thank you very much in advance.
You need to do two things to make this work:
Remove the 127.0.0.1 part of the port mapping; docker run -p 8888:8888 ...
Connect to the docker-machine ip address with the published port; http://192.168.99.100:8888.
Docker Toolbox runs Docker in a separate Linux virtual machine. Any docker run -p options will get interpreted from the point of view of that VM. If you docker run -p 127.0.0.1:... then the published port will be bound to the VM's lo0 localhost interface, so it won't be reachable from outside the VM.
Once you have the port published, you need to connect to that specific port. Port 2376 is typically the port to reach the Docker daemon inside the VM, with mutual TLS security; you only need this for manual docker commands. To reach services running inside the VM you need to connect to the published port (the first number in the docker run -p option).

How to access Docker Selenium hub console in browser?

I am running docker selenium hub on windows. The container is up as docker log shows. However I am confused at what is the actual hostname that the hub uses. When i use conventional Selenium hub, I can use http://localhost:4444/grid/console to check that it's running correctly. But in this case of docker, I am confused at the printing of Docker log.
I tried 0.0.0.0, localhost, 172.17.0.2 as hostname to open /grid/console in browser. None of them works.
Also when I tried to use 'netstat -a' to list all tcp connections, I do not see any of them has port 4444.
Could anyone let me know what went wrong?
You are running docker on windows, there are two things you can do.
Map your port 4444 to host when starting the container.
On windows, your container is ruining in Boot2Docker virtual machine.
So instead of http://localhost:4444/grid/console use
http://{ip of boot2docker vm}:4444/grid/console
To get IP on boot2docker machine try the following command:
docker-machine ip default
Port expose docker example:
docker run -d -p 4444:4444 --name <container-name> <image-name> 

How to access docker container via its Ip from the host

I want to be able to access a docker container via its Ip eg the one I can see when I do docker container inspect foo
The reason is I am using zookeeper inside a docker container that is managing two other docker containers running solr. My code (not in docker and I don't at this stage want it to be) calls zookeeper to get the urls of the solr servers which zookeeper reports as the docker containers ip. My code then falls over because calling the docker containers ip from the host fails as it should be calling localhost.
So how can I allow a call to the docker containers ip from the host to be routed correctly. (I am using Docker native for Mac)
I'm not using Docker for Mac, so I'm not sure the newest version Docker for Mac is still based on Docker-machine (which based on VirtualBox) or not.
If you can confirm your Docker for Mac is based on VirtualBox, then you probably could get the inet IP of vboxnet0 network interface via ifconfig command. This IP should be used as your calling IP.
Besides, you should know the port number of your Zookeeper container. Normally the exposed port of a container could be configured in docker run command, for example:
docker run -p 5000:5001 -i -t ubuntu /bin/bash
Where -p indicated the exposed port of the container.

Docker - Access mapr UI from host

I have installed docker on a CentOS machine. Now I am trying to run a MapR sandbox on it. After starting I get this:
Starting MapR Services.................
To manage this node go to: https://172.17.0.13:8443
But I am not able to access this URL from the windows machine in the same network as the CentOS machine.
This is an internal docker network inaccessible outside of the box. In order to access this container you need:
EXPOSE command in container (most likely it is already there)
run container with -p option
If you just specify -p port will be random - you could find it with inspect command, or you could use permanent port -p hostIp:externalPort:8443 where hostIp is address of your docker host.
After that you could access container from network as https://hostIp:externalPort

Obtaining the ip address of a docker container

I have a ubuntu machine which is a VM where I have installed docker in it. I am using this machine from my local windows machine and doing ssh , opening the terminal to the ubuntu machine.
Now , I am going to take a docker image which contains all the necessary softwares for eg: apache installed in it. Later I am going to deploy a sample appication(which is a web applicationP on to it and save it .
Now , I am in a confused mode as in how to check the deployed application if its running properly. i.e., what would be the address of the container which containds the deployed application.
for eg:- If I type http://127.x.x.x which is the address of the ubuntu machine , I am just getting time out .
Can anyone tell me how to verify the deployed application . Also, the printing the output of the program on the console works seemlessly fine , as the output gets printed , only thing I have some doubts is regarding the web application.
There are some possibilities to check whether your app is running.
Remote API
As JimiDini said, one possibility is the Docker remote API. You can use it to see all running containers (which would be your use case, right?), inspect a certain container or start and stop containers. The API is a REST-API with several binding for programming languages (at https://docs.docker.io/reference/api/remote_api_client_libraries/). Some of them are very outdated. To use the Docker remote API from another machine, I needed to open it explicitly:
docker -H tcp://0.0.0.0:4243 -H unix:///var/run/docker.sock -d &
Note that the API is open to the world now! In a real scenario you would need to secure it in some way (e.g. see the example at http://java.dzone.com/articles/securing-docker%E2%80%99s-remote-api).
Docker PS
To see all running containers run docker ps on your host. This will list all running containers. If you do not see your app, it is not running. It also shows you the ports your app is exposing. You can also do this via the remote API.
Logs
You can also check the logs. You can run docker attach <container id> to attach to a certain container an see its stdout. You can run also run docker logs <container id> to receive the Docker logs. What I prefer is to write the logs to a certain directory, e.g. all logs to /var/log and mount this folder to my host machine. Then all your logs will end up in /home/ubuntu/docker-logs on your host.
docker run -p 80:8080 -v /home/ubuntu/docker-logs:/var/log:rw my/application
One word to ports and IP
Every container will get its own IP address. You can check this IP address via the remote API or via Docker on the host machine directly. You can also specify a certain host name for the container (by passing the --hostname="test42" to the run command). However, you mostly did not need that.
To access the application in the container, you need to open the port in the container and bind to a port on the host.
In your Dockerfile you need to EXPOSE the port your app runs on:
FROM ubuntu
...
EXPOSE 8080
CMD run-my-app.sh
When you start your container, you need to bind this port to a port of the host:
docker run -p 80:8080 my/application
Now you can access your app on http://localhost:80 or http://127.0.0.1:80.
If you app does not response, check if the container is running by typing docker ps or the remote API. If it is not running, check the logs for the reason.
(Note: If you run your Ubuntu VM in something like VirtualBox and you try to access it from your Windows machine, make sure you opened the ports in VirtualBox too!).
Docker container has a separate IP address. By default it is private (accessible only from the host-machine).
Docker provides all metadata (including IP address) via its API:
https://docs.docker.io/reference/api/docker_remote_api_v1.10/#inspect-a-container
https://docs.docker.io/reference/api/docker_remote_api_v1.10/#monitor-docker-s-events
You can also take a look at a little tool called docker-gen for inspiration. It monitors docker-events and created configuration-files on host machine using templates.
To obtain the ip address of a docker container, if you know its id (a long hex string) or if you named it:
docker inspect --format '{{ .NetworkSettings.IPAddress }}' <container-id-or-name>
Docker is running its own network and to get information about it you can run the following commands:
docker network ls
docker network inspect <network name>
docker inspect <container id>
In the output, you should be able to find the IP.
But there is also a couple of things you need to be aware of, regarding Dockerfile and docker run command:
when you EXPOSE a port in Dockerfile, the service in the container is not accessible from outside Docker, but from inside other Docker containers
and when you EXPOSE and use docker run -p ... flag, the service in the container is accessible from anywhere, even outside Docker
So for example, if your apache is running on port 8080 you should expose it in Dockerfile and then you can run it as:
docker run -d -p 8080:8080 <image name> and you should be able to access it from your host on HTTP://localhost:8080.
It is an old question/answer but it might help somebody else ;)
working as of 2020
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name_or_id

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