I'm using docker desktop for mac.
I have built a docker image for a Node.js app that connects to an external MongoDB database via URI (the db is running on an AWS instance that I'm connected to over vpn). This works fine - I run the container and the app can connect to the database. Happy days.
Then...
I enable Kubernetes on docker desktop. I apply a deployment.yml to run the container but this deployment fails when trying to connect to the db. From my app's logs (I'm using mongoose):
MongooseServerSelectionError: connect EHOSTUNREACH [MY DB IP] +30005ms
Interestingly...
I can now no longer connect to the db by running my docker container either. I get the same error.
I have to disable kubernetes, restart docker desktop (twice), prune my previous container and network, and re-run my container. Then it will work again.
As soon as I enable kubernetes again, the db becomes unreachable again.
Any ideas why this is and/or how to fix it?
So the issue for us turned out to be an IP range clash. Exactly the same as described in this SO question:
Change Kubernetes docker-for-desktop cluster network ip
Unfortunately, like this user, we haven't been able to find a solution
Related
I have been able to set up containerised RabbitMQ server, and reach into it with basic .NET Core clients and check message send and receive working using management portal on http://localhost:15672/.
But I am having real frustrations when I also Containerise my Sender/Receiver .NET Core clients, on being able to establish a connection. I have set up an explicit "shipnetwork", so all containers in the following docker-compose deployment should see each other.
This is the Error I get in the sender attempting the connection:
My SendRabbit .NET core App is as follows. This code was working on my local Windows 10 development machine, with a host of 'localhost' against the RabbitMQ server running as a container. But when I change this to a [linux] docker project, and set the host to "rabbitmq", to correspond to the service name in the docker compose. Now I just get Endpoint Connection errors exceptions within my Sender container.
I have also attempted the same RabbitMQ server and Sender Image with the same docker-compose on a Google Cloud Linux Virtual Machine, and get the same errors. So I do not think it is the Windows 10 docker hosting VM environment hassles.
I thought docker was going to make development and deployment of microservices, but setting up a basic RabbitMQ connections is proving to be a real pain.
I have thought that maybe the rabbitmq server is not up and running, so perhaps ambitious to put in the same docker-compose. But I have checked running my SendRabbit container
$docker run --network shipnetwork sendrabbit
some minutes later. But I still get the same connection error
docker networks **** networks !
When I checked the actual docker networks, I had:
bridge
host
shipnetwork
rabbitship_shipnetwork
The docker compose was actually creating the 'new' network: rabbitship_shipnetwork every time it was spun up, and placing the rabbimq server on that network. The netwrok is named from appending the directory name, with the name in the compsos yaml. So I was using the wrong network in my senders. So I should have been using
$docker run --network rabbitship_shipnetwork sendrabbit
This works fine, and creates messages into the rabbitmq server
So I don't feel that docker-compose is actually very helpful in creating networks, since it is sensitive to the directory name it is run in ! Its unlikely that I can build an app .docker files, and deploy all Apps from a single directory, especially when rabbitmq has to be started separately, before senders and receivers can use it.
docker-compose 0
I have a VM running Ubuntu 16.04, on which I want to deploy an application packaged as a Docker container. The application needs to be able to perform an HTTP request towards a server under VPN (e.g. server1.vpn-remote.com)
I successfully configured the host VM in order to connect to the VPN through openconnect, I can turn this connection on/off using a systemd service.
Unfortunately, when I run docker run mycontainer, neither the host nor the container are able to reach server1.vpn-remote.com. Weirdly enough, there is no error displayed in the VPN connection service logs, which is stuck to the openconnect messages confirming a successful connection.
If I restart the VPN connection after starting mycontainer, the host machine is able to access server1.vpn-remote.com, but not the container. Moreover, if I issue any command like docker run/start/stop/restart on mycontainer or any other container, the connection gets broken again even for the host machine.
NOTE: I already checked on the ip routes and there seems to be no conflict between Docker and VPN subnets.
NOTE: running the container with --net="host" results in both host and container being able to access the VPN but I would like to avoid this option as I will eventually make a docker compose deployment which requires all containers to run in bridge mode.
Thanks in advance for your help
EDIT: I figured out it is a DNS issue, as I'm able to ping the IP corresponding to server1.vpn-remote.com even after the VPN connection seemed to be failing. I'm going through documentation regarding DNS management with Docker and Docker Compose and their usage of the host's /etc/resolv.conf file.
I hope you don't still need help six months later! Some of the details are different, but this sounds a bit like a problem I had. In my case the solution was a bit disappointing: after you've connected to your VPN, restart the docker daemon:
sudo systemctl restart docker
I'm making some inferences here, but it seems that, when the daemon starts, it makes some decisions/configs based on the state of the network at that time. In my case, the daemon starts when I boot up. Unsurprisingly, when I boot up, I haven't had a chance to connect to the VPN yet. As a result, my container traffic, including DNS lookups, goes through my network directly.
Hat tip to this answer for guiding me down the correct path.
I created a couchbase 4.0 docker container with single node on windows 10. And added node ip in host machine loopback and forwarded port in vitural box so that couchbase client in my app running in host can connect with node in cluster. I was able to connect and do db operation when I have single node in cluster.
However when I created multiple node cluster in docker on windows 10. I was not able to do db operation. In golang app running in host I got message unable to complete action after 6 attemps on get and set operation.
How to run couchbase cluster of multiple nodes in docker on same host in windows machine so that I can connect with cluster and do db operation from app running in host machine.
If your app is not running inside of Docker host, as far as I know, you can't do this (I would LOVE to be proven wrong by a Docker expert).
Couchbase clients need access to every node in the cluster, and with Docker you can only forward one image to a given port outside the host. (FYI, there is a tool called sdk-doctor which you can use to verify connectivity/networking issues called SDK Doctor).
I would suggest running your golang app inside of the Docker host (using docker-compose is the way this is typically done).
Also, I would highly suggest upgrading to a more recent version of Couchbase.
I have a system of three small Spring Boot apps, each to serve a different purpose, which contain REST endpoints. The three apps are meant to all work off of the same database (MariaDB). Right now, the system works as four separate dockers. Three docker containers for the three apps, and a fourth container for the MariaDB (based on MariaDB Docker image). All three app containers connect to the database container using the --link network pattern.
Each of the app dockers were launched from the same image, using:
docker run -i -t -p 8080:8080 --link mariadb:mariadb javaimage /bin/bash
This docker system currently works as expected. All three apps can call the MariaDB, each app is accessible from the host machine via REST calls by calling http://localhost:8080/pathToEndpoint. The project has recently expanded and a new requirement has been added. We are using Netflix Eureka as a service lookup point, which should in the future help allow these Docker's to be deployed anywhere with minimal changes needed to the software calling the Docker's. Netflix Eureka requires me to effectively "check in" when the app is launched. This is all handled by Spring Boot itself, so when the app is launched this "check in" is apart of the startup process. The Eureka server is on the same network as the host machine, and for the time being is being accessed via an ip address. If the Spring Boot applications running this Eureka check-in component are launched directly on the host machine, everything works as expected. The app makes a successful call to the Eureka server and notify it of the app's existence. If I run the same app within a Docker container on the same host machine, this fails as the connection is refused. Upon investigation I found I could not even ping the ip address of the Eureka server from within the Docker container, explaining why it is failing. I continued a little further into testing what does and does not work, and found I can ping external sites such as google without a problem, but any internal to my network servers are un-reachable when I try to ping them from within the Docker container.
Therefore my question is, what network configuration I am missing to cause this? I recognize that Docker has quite a lot of network configuration options, but I have not been able to find someone with a similar issue.
Any help is appreciated. Thank you!
Note: Question is related to Bluemix docker support.
I am trying to connect two different Docker Containers deployed in Bluemix. I am getting the exception:
java.net.NoRouteToHostException: No route to host
when I try such connection (Java EE app running on Liberty trying to access MySQL). I tried using both private and public IPs of MySQL Docker Container.
The point is that I am able to access MySQL Docker Container from outside Bluemix. So the IP, port, and MySQL itself are ok.
It seems something related to the internal networking of Docker Container support within Bluemix. If I try to access from inside Bluemix it fails, if I do from outside it works. Any help?
UPDATE: I continued investigating as you can see in comments, and it seems a timing issue. I mean, it seems once containers are up and running, there is some connectivity work still undone. If I am able to wait around 1 minute, before trying the connection it works.
60 seconds should be the rule of thumb for the networking start working after container creation.