I have a setup that looks like this:
Essentially, two physical machines that exist on the same local network and each machine is running the same docker image. I have exposed a range of ports on both physical machines (2000-3000). The docker image used has both SSH and OpenSSH server installed, and when run, port 22 is mapped to 2222. What I would like to be able to do is SSH from Docker Image Machine-01 to Docker Image Machine-02.
I realize that docker attach, etc exist, however, I do have a specific use case for my application.
I know that my ports are open as I can have netcat listening on one machine, and then use nc -zv machine-02 2000 and get a response. Where I am stuck is getting the connection between the two docker images. It should be noted that I can SSH into the docker image locally (machine-01 can get into its own image, but machine-02 cannot access this)
What is the best way of proceeding with this?
Related
I'm using Jenkins on Docker on my local Mac Machine.
And I'm running another Docker on ubuntu VirtualBox. So now, there are 2 docker machines. one is on my mac machine and one is on my Ubuntu VirtualBox machine. I'm running Jenkins on Mac Docker. Now in the Jenkins pipeline, I want to build an image on my ubuntu machine.
I've configured Jenkins docker cloud and in the docker host URL, it is connected to the ubuntu docker-machine.
But while building a new image, I'm getting the error. Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
I've tried even adding ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:4243 -H unix:///var/run/docker.sock
at /lib/systemd/system/docker.service
WHen i check ps -aux,
Can someone please help me out?
help is appreciated.
First personally if I had a setup like that I would not bother connecting to the remote docker and would just install a Jenkins agent on the ubuntu machine and make it talk to the Jenkins master.
But if you want to do it they way you have it set up right now we a Jenkins talking from inside out one docker host into another docker host I suggest looking into the following:
Your Jenkins master and the ubuntu machine a very isolated they might as well just be on different machines not even in the same room. Unix domain sockets, the ones that are identified by unix://* are made for communicating within a single local OS kernel, trying to bridge them into remote machine will lead to disaster.
So the only way Jenkins could communicate to the remote host is via a remote protocol like TCP. Most of the time when you install docker with the default settings it doesn't even listen to TCP at all, mostly for security reasons.
First thing you should do is to configure a docker inside of the ubuntu machine to listen on TCP port and accept connections from remote hosts. You can use netstat -nat to see if anything is listening on TCP 4243. When things are configured correctly you see the line that stats with 0.0.0.0:4243 or something like that in the output of the nestat
Second you need to make sure your the firewalls/iptables/netfilter configuration on the Ubuntu host lets in connections from outside. A good test to try is to telnet <ubuntu-ip> 4243 from a terminal session on your Mac.
Then you need to make sure you that docker networking is configured correctly so that connections from the inside of the container that is running Jenkins end up on your ubuntu box. To test you need to exec -it into your jenkins container and repeat the telnet test. On modern linuxes telnet is usually not installed, so you can use curl -vvv which will always end up with an error, so just look at the verbose output to see if the error because things cannot communicate (timeout, connection reset etc) or the error occurs because your curl tried to talk HTTP to docker and got gibberish response. In the later case you can consider things to be set up correctly.
Finally you need to tell Jenkins Docker to communicate to the remote docker via TCP. Usually that is given on the command line to your docker run, docker ps, docker exec
I've configured it by defining the slave label in my Jenkins Pipeline.
Jenkins agents run on a variety of different environments such as physical machines, virtual machines, Kubernetes clusters, and Docker images.
In your Jenkins Pipeline or In your JenkinsFile, you've to set the agent accordingly to what you're using either using Docker image or any virtual machine.
Also Thank you so much #Vlad, all the things you told me, were really helpful.
I cannot connect to the published port on the swarm that uses overlay networking. I am using Docker for Windows with Windows containers. Both Windows and Docker are fully upgraded. After Windows' 1709 update, I was hoping this issue would be resolved. I looked for information on the Internet to see if I was doing something wrong to no avail. I would like to know if anyone was successfully able to get it working.
On a side note, when I direct the port on my machine in docker run -p 80:80 without using swarm, "localhost" does not work as well. I think this is a known limitation though. Both issues work when I switch to Linux containers.
Expected behavior
I am running a dotnet kestrel web server service. I should be able to connect to my service using the published port.
Actual behavior
Firefox gives me timeout, opera straight away returns connection refused. Cannot telnet into it either. Container IP's assigned by the overlay network do not work either.
Information
docker service ls gives me this:
Ports cannot be seen there, is it because publish mode is host? Ports information is available in the output of docker service ps
And when I change the publish mode, I can scale it as well and the port information is seen in docker service ls albeit still cannot connect. the one below is without the publish mode=host parameter:
For more info, this is the output of the docker network ls I wonder if i need some sort of bridge network like in Linux.
Steps to reproduce the behavior
Initialise swarm
Start the service, in my case: a simple web service built using aspnetcore:latest image. I tried different parameters, even used a docker-stack.yml:
docker service create --name=web --publish mode=host,published=80,target=80 web:aspnetcorelatest in the case above, I was unable to scale it on the same machine, which is normal i guess
docker service create --name=web --publish published=85,target=80 web:aspnetcorelatest
Try to connect using one of http://localhost or another IP. I tried connecting over VPN, from another machine as well as Internet IP.
I am currently thinking of building a docker image for my ipython parallel nodes. Because its a pain to configure each manually with commands. Will i be able to access this image (located on a different PC on my LAN) simply by typing ssh user#ip on my laptop (Master Node)? How do i get the ip of the docker image running on my Node?
Will i be able to access this image (located on a different PC on my LAN) simply by typing ssh user#ip on my laptop (Master Node)?
You cannot ssh into a container unless you arrange to run sshd inside that container. Normally that's not necessary; as this answer explains you can simply use docker exec to access a running container.
How do i get the ip of the docker image running on my Node?
First, a note about nomenclature: an image is just a collection of files. A container is what you get when you start services from an image. In other words, it doesn't make sense to ask questions about accessing or getting the ip address of an image.
You can get the ip address of a container using the docker container inspect command, which will show you a variety of information about your container. However, this may not be what you want: the ip address of the container will be a private ip address on a docker internal network that is only accessible from the host where you're running docker.
You provide remote access to services by using port forwarding (the -p flag to docker run). For example, if you're running a webserver on port 8080 inside a container, you could make that available on port 80 on your host doing something like:
docker run -p 80:8080 mywebserver
This document describes in more detail some of the options related to port forwarding.
we have two machine…one is windows machine and another in Linux machine. My application is running under Docker Container at Linux machine. our data base is running at Windows machine.our application need to get data from windows machine DB.
As we have given proper data source detail like IP, username ,password in our application. it works when we do not use docker container but when we use docker container it do not work.
Can anyone help me out to get this solution that how we can connect outside DB from Docker enabled application as we are totally new guys in term of Docker.
Any help would be much appreciated.
Container's default network is "bridge",you should choose macvlan or host network.
method 1
docker run -d --net host image
this container will share your host IP address and will be able to access your database.
method 2
Use docker network create command to create a macvlan network,refrence here
then create your container by
docker run -d --net YOURNETWORK image
The container will have an IP address which is the same gateway with its host.
There are a lot of issues that could be affecting your container's ability to communicate with your database. In the future you should compose your question with as much detail as possible. To correctly answer this you will, at a minimum, need to include the following details:
Linux distribution name & version
Docker version
Output of docker inspect from the container
Linux firewall configuration
Network configuration
Is your Windows machine running on the same local network / subnet as your Linux machine? If so, please provide information about the subnet, as the default bridge set up by Docker may restrict access to local resources, whereas those over a wide area network would still be accessible.
You can try passing the --network=host option to your docker run command like so: docker run --network=host <image name>. Doing so eliminates the need to specify port mappings in your run command, as they are ignored when using the host's network.
Please edit your question and include the above requested details to get a complete answer.
I'm getting in habit with rancher and docker and I'm now trying to figure out if it is possible to create multiple local custom hosts on the same physical machine. I'm running RancherOS in a local computer. Through the Rancher Web UI I'm able to create a local custom host and add containers to it.
When I try to add another local custom host copying the given command to the terminal (SSH into the rancher machine) it stars the process but nothing happen. The new host doesn't appear in the hosts list of the web interface and I don't receive any error from the terminal.
I couldn't get any useful information from the Rancher documentation about this possible issue.
I was wondering if it's not possible to have more than one custom virtual host on the same physical machine or if the command fails for some reason that I would like to know how to debug.
sudo docker run -e -d --privileged \
-v /var/run/docker.sock:/var/run/docker.sock rancher/agent:v0.8.2 \
http://192.168.1.150:8080/v1/projects/1a5/scripts/<registrationToken>
where registrationToken is replaced by the one provided by rancher.
There is nothing "virtual" about them. The agent talks to docker and manages one docker daemon, which is the entire machine. Running multiple does not make sense for a variety of reasons, such as when you type "docker run ..." on the machine, which agent is supposed to pick up that container? And they are not really isolated from each other regardless, because any of them can run privileged containers which can then do whatever they want that affects the others.
The only way to do what you're asking is to have actual virtual machines running on the physical machine, each with their own OS and docker daemon.
Another option might be to use linux containers to create separated environments, each having it's own ip address and running it's own docker daemon.