For my personnal developping environement, I'm trying to learn docker and the best pratices for good configuration. But now I have à lot of question about how docker is working.
I'm on windows then I'm using hyper-v for running MobyLinuxVM, first I would like to know if it's possible to connect my-self to the VM to see what is inside and what is used for. Secondly I would like to know what this VM is used for? Is it for the deamon? Thirdly I would like to know where the daemon is set (wath is running) then what is the job of the service com.docker.service? Finaly is there a way by commande line to show the actual deamon ip and port and an example to show how the docker cli is connecting to?
Thanks, if someone is able to help me, because I'm a little bit lost.
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I used the zabbix official docker-compose yaml to set up a set of zabbix system and I found the server as a monitoring target was not available. I searched the Internet and found there are people also encountered such problem.Someone said the agent container's IP or DNS name should be used as the server's. I tried and found it works. But I'm confused by the agent. Does it monitor the server container,the agent container or the host machine? If it only monitors the agent container itself,what's the purpose of it?
Does it monitor the server container,the agent container or the host machine?
Agent container.
If it only monitors the agent container itself,what's the purpose of it?
For testing. And for monitoring external stuff, with custom commands. Or you can connect stuff from host and monitor it, so just in all the cases you do not want or can't install agent on the host.
Everybody who configures a Dockerized Zabbix installation like yourself bumps into to this issue- and of course find themselves on StackExchange looking for the answers that should have been in the documentation.
The reason that the Zabbix Agent in the docker-compose install you're referring to can't initially connect is that both it and server it monitors both run in isolated containers. Separate containers cannot talk to each other on 127.0.0.1 (localhost) addresses. And that is actually a good thing!
I've reviewed the documentation in the repo you're talking about and it's sparse to say the least; it certainly could be better. But to be fair to Zabbix, their docker-compose install DOES work great when you get it running and can achieve pretty fair results quickly with little effort (and a bit of Googling ;-> ).
I actually found FURTHER pain connecting to containerized Zabbix Agents raised on different hosts outside of the docker-compose install you're referring to. Connectivity was being busted because the host the docker-compose install was raised on was NAT'ing out the traffic and presenting the wrong IP address. I've documented this issue HERE.
Dockerized Zabbix is a good thing; there is a purpose to it. I agree with you though that the documentation could be better though. Stick with it!
I have a windows machine. I am running ubuntu using the virtual box on top of it. From windows, I am sending certain information to ubuntu over UDP on a specific port. I am running multiple Docker containers in ubuntu. I want to forward this data to all the containers from ubuntu. Could someone please specify a method to achieve this.
I am answering to my question.
I have written a script in python which listens on the specified port and broadcasts it over the docker network. Every container created on that network receives it.
Despite your own answer, you could use nginx to achieve such behavior. Dont need to rewrite what is already implemented but since your script work's i guess you will stick with your solution. Consider this answer mainly for future reader's therefore.
I have one weird thing to configure is that Can I have docker daemon per user on Host? I want to isolate the process where individual user can have his own docker daemon where the user can run his own services/images/containers and test it. Basically I need this for testing environment where each user shall have his own set of services.
I could see that there is something called docker bridge but I am not sure If I can extend it. Can someone please suggest me somethings.
Edit 1 : Can I use docker-machine for the same? but I am not finding the way to configure it.
I could achieve this with my own Solution. Basically this is easily achievable with custom docker daemon configurations.
This link has all the details. Dockerd
And this talks on securing the tcp socket between client and engine secure docker connection
However running multiple daemons is still a experimental features since global configurations such as Iptables are part of it. For my case I do not need it hence disabled those.
Note : This is adaptable for my use case. If you are with similar scenario and with extra configurations I recommend you to read the Docker Documentation and also a Stackoverflow question if it does not satisfy the thirst.
I'm not sure if this is an issue with the current version of Windows Docker network or poor configuration and misunderstanding on my part, but I have the following setup:
2 Docker containers (built using the Microsoft/ASP.NET image as a base) running a .NET MVC application in each.
1 Docker container running SQL server (built using the Microsoft/mssql-server-windows image)
When I create all 3 containers everything works great, I can attach and ping all other the other containers using their names without any issue. The applications run and can communicate with each other as I hoped.
However, when I reboot my machine and start all the containers again they can no longer ping/communicate with each other using their names (using IP addresses is fine).
I've tried this on the default NAT network and also tried replacing the NAT network with my own custom NAT network.
To resolve the issue I have to run the force network disconnect command for each container as such:
docker network disconnect nat <containername> --force
And then I have to reconnect each container to the network before starting them up. All containers can then ping/communicate with each other using their names as well as their IP addresses.
FYI, this is a development environment but I was hoping to do something similar in Azure using a Windows Server 2016 VM, although I don't quite know what the best network configuration is for live production yet as I need to have multiple applications (in separate containers) on the same node accessed via their own subdomains.
Any help or guidance would be great.
I'm not sure, in part because this question was asked several months before any other example I've run into, but this sounds very similar to the problem described at https://github.com/docker/for-win/issues/1038.
Basically, there appears to be a problem introduced with the 1709 update to Windows 10 which results in a scenario where Hyper-V networking doesn't work the way it ought to.
There appear to be two common ways of working around this problem: Turning off "Fast Start" in the Control Panel => Power Options => System Settings, or restarting Docker for Windows and any containers after booting. I also thought I saw something on a Microsoft blog post indicating that the underlying problem has now been resolved and will be included in an update to Windows 10, but alas I can no longer find that information or the specific version number in which the problem was (theoretically) resolved. It may well be the delayed 1803 "Spring Creators Update" release.
I'm currently looking into Mesosphere DCOS to run multiple micro-services using Docker containers. Each micro-services code is already built by my CI into a docker container and uploader to a private container repo.
If I now deploy container A and container B as two different apps using Marathon, how would app A be able to reach app B?
Do I need additional service discovery like Consul?
Would be great if I could have some insights here and maybe even some links / docu to get me started :)
The current solution would be to use some kind service discovery.
DCOS already comes with MesosDNS and it will automatically create an DNS entry for each of your containers started by marathon.
See here for details on using MesosDNS on DCOS.
Hope this helped!
BTW: Feel free to contact the DCOS support directly via the little chat icon in the DCOS UI.