I know this is a bit long question but any help would be appreciated.
The short version is simply that I want to have a set of containers communicating with each other on multiple hosts and to be accessible with SSH.
I know there are tools for this but I wasn't able to do it.
The long version is:
There is a software that has multiple components and these components can be installed in any number of machines. There is a client- and a server-side for this software.
Both the client-server and the server side components communicate via UDP ports.
The server uses CentOS, the client uses Microsoft Windows.
I want to create a testing environment that consists of 4 containers and these components would be spread across these containers and a client side machine.
The docker host machine is Ubuntu, the containers are CentOS.
If I install all the components in one container it's working, if there are more than it's not. According to the logs its working but its not.
I read that you need to link the containers or use an orchestrator like Maestro to do this, but I wasn't able to do it so far.
What I want is to be able to start a set if containers which communicate with each other, on one or multiple hosts. I want to be able to access these containers with ssh so the service should start automatically.
Also it would be great to use ddns for the containers because the names would be used again and again but the IP addresses can change, but this is just the cherry on top.
Some specifications:
The host is a fresh install of Ubuntu 12.04.4 LTS x86_64
Docker is the latest version. (lxc-docker 0.10.0) I used the native driver.
The containers a plain simple centos pulled from the docker index. I installed some basic stuff on the containers: openssh-server, mc, java-jre.
I changed the docker network to a network that can be reached from the internal network.
IP tables rules were cleared, because I didn't needed them, but also tried with those in place but with no luck.
The /etc/default/docker file changes:
DOCKER_OPTS="--iptables=false"
or with the exposed API:
DOCKER_OPTS="-H tcp://0.0.0.0:4243 --iptables=false"
The ports that the software uses are between 6000-9000 but I tried to open all the ports.
An example of run command:
docker run -h <hostname> -i -t --privileged --expose 1-65535/udp <image> /bin/bash
I also tried with exposed API:
docker -H :4243 run -h <hostname> -i -t --privileged --expose 1-65535/udp <image> /bin/bash
I'm not giving up but I would appreciate some help.
You might want to take a look at the in-development docker swarm project. It will allow you to treat your set of test machines as a cluster to which you can deploy containers to.
You could simply use fig for orchestration and link the containers together instead of doing all that ddns and port forwarding stuff. The fig.yml syntax is pretty straight-forward.
You can use weave for networking part. You can use these tutorials
https://github.com/weaveworks/weave
http://xmodulo.com/networking-between-docker-containers.html
Related
Now I have two Linux PC,mongodb is in the first PC which IP is 192.168.1.33,and a
java application on another Linux connect to the mongodb on 192.168.1.33
What I want to do is,prepare everything and make both Linux systems into docker images,and when I am in productive environment,I can simply restore the images that I prepared,and everything is OK,so I do not need complex deployment steps.
but the problem is,the IP of mongodb will change,and the IP 192.168.1.33 is written in my configuration file of my java application,it will not change automatically,is there a automated way?
Basics
We create Docker-file with minimal installation steps.
We create docker-Image from that Docker-file in step-1.
We create container from the step-2 image and expose the important port as required.
For your problem.
creating-a-docker-image-with-mongodb This article will help to dockerize the mongodb.
but the problem is,the IP of mongodb will change,and the IP
192.168.1.33 is written in my configuration file of my java application,it
will not change automatically,is there a automated way?
If you expose the mongo-db port to docker host you can use same
docker-host-IP:<exposed-port>
Ref from the article sudo docker run -p 27017:27017 -i -t my_new_mongodb
Example: 192.168.1.33 is your docker-host where mongodb container is running with exposed port 27017. You can add 192.168.1.33:27017 to your JAVA app.
What I want to do is,prepare everything and make both Linux systems
into docker images
You can not convert your VM to direct docker images. Instead you can follow the steps written in Basics and dockerize the both DB and application layer.
2.dockerize-your-java-application refer this link and dockerize you application based on requirements.
Step 1 & 2 will help you to build docker images which you can deploy to multiple servers.
I have a VPS running Debian 8 with Docker. I want to give my customers some kind of terminal access to there container trough the web interface.
What's the best way of implementing this? And does anyone has some kind of example.
Cheers,
Ramon
You can spin your own web interface easily since Docker includes a REST based API. There are also plenty of existing implementations of this out there, including:
Universal Control Plane
UI for Docker
Docker WebUI
And various others if you search Docker Hub.
Because you're also asking for examples: A very easy implementation for a UI is the following:
install the docker engine (curl -sSL https://get.docker.com/ | sh)
Start the docker daemon: (sudo service docker start)
Run the ui-for-docker container and map the port 9000:
docker run -d -p 9000:9000 --privileged -v /var/run/docker.sock:/var/run/docker.sock uifd/ui-for-docker
access server-ip:9000 in your browser.
If you want just know what is happening in your docker registry, than you also may want to try this UI for Docker Registry. It is a bit "raw" now, but it has features that other have not.
It shows dependence tree (FROM directive) of stored images.
It shows pretty statistics about uploads number and image sizes.
Can serve multiple repositories.
I'm running Docker 1.7 and docker-compose 1.5.2 on Oracle Enterprise Linux (OEL) 6 with a 2.6 kernel.
I have adapted the CitusDB docker-compose.yml file in a few minor ways, except the main thing is that I only have one 'worker' entry and I use docker-compose scale to increase the numbers of workers. This works fine on the Docker 1.10/Docker-compose 2 configurations I was developing on, but these were using VirtualBox VMs under OS X/docker-machine.
Now to deploy on a regular native Linux box, I'm back-revved and the 'master' container cannot connect to the workers.
Port 5432 (standard PostgreSQL) is exposed, and each worker container has a different IP address, and they get put into /etc/hosts on the master, but the master cannot connect to the workers.
I saw some messages about the firewall. The Linux box is using iptables. When I start up using docker-compose, it creates an iptables DOCKER entry.
I tried disabling iptables and it did not change the results.
I tried creating alternative networks using the docker-compose net: directive and there was no difference.
Apologies for asking two unrelated questions.
what is the best way of accessing the host machine of the docker container (i.e. I am trying to access a kafka instance running on the host, from my docker container so that I can publish some messages)
when I run docker run ..... on an image which I've modified that may have an issue/syntax error, it will naturally not start - is there a log file anywhere that I would be able to take a look at to debug the issue. (this question is somewhat related to the 1st question, since I did what was suggested on another post, but the image is still not starting)
This is an ongoing discussion on what to use and what not, I don't really know what is best. Using the docker run --net="host" is pretty easy but can be dangerous. See From inside of a Docker container, how do I connect to the localhost of the machine?.
Use docker logs containerid or lookup the raw data in /var/lib/docker/containers/containerid/ for Ubuntu.
You should have no problem connecting to the host using the local lan interface ip address. Suppose you have a host with ip 192.168.0.1:
docker run --rm -ti ubuntu bash
ping 192.168.0.1
should give you a response.
You can use docker logs to see the standard output of your container.
Is there any to way to communicate among docker containers other than via sockets/network? I have read docker documentation which says we can link docker containers using --link option but it doesn't speicify how to transfer data/msg from one container to another. I have already created a container named checkram.
Now I want to link a new container with this container and I run
docker run -i -t --privileged --link=checkram:linkcheck --name linkcont topimg command.
Then i checked env variable LINKCHECK_PORT in linkcont container which contains tcp://172.17.0.14:22.
I don't know what to do with this ip and port and how to communicate with checkram container from linkcont container. can anyone help me out of this? Thanks in advance.
There are several tools you can use to achieve running multiple docker containers and interact with them. docker has a tool: docker Compose where you can build and interact multiple containers.
Another tool that works as well: decking you can also use FIG, but i found decking was very straight forward and easy to configure. At that time when i was using decking, docker compose was not released yet. docker compose is a newer tool, yet it is developed by docker.