I have installed Docker Desktop locally (Windows 11 OS) and enabled Kubernetes cluster in it. By default the Docker desktop creates 2 entries in the host file -> host.docker.internal and kubernetes.docker.internal. I am running spring boot application which is dockerized and I have put it inside the kubernetes cluster. I am trying to connect to local database (MSSQL) via passing the config as kubernetes.docker.internal and host.docker.internal in the application.yml. However, it is complaining as host not found. Is there any specific config which I might be missing?
Related
I have recently started exploring the microservice architecture using jhipster and was trying to install and run the jhipster-registry from docker hub. Docker shows that the registry is running, but I am unable to access it on port 8761.
Pulled the image with docker pull jhipster/jhipster-registry
Started the container with docker run --name jhipster-registry -d jhipster/jhipster-registry
Here's a snapshot of what docker container ls returns:
Am I missing something over here?
You are starting the JHipster Registry container, but you aren't exposing the port.
You can expose a port by passing the port flag -p 8761:8761 which will enable you to connect to it via localhost:8761 or 127.0.0.1:8761 in a browser.
You may need to configure some environment variables for the JHipster Registry to start correctly. These may depend on your generated app's options, such as authentication type. For convenience JHipster apps come with a docker-compose.yml file. You can start it with docker-compose -f src/main/docker/jhipster-registry.yml up, as documented.
Hi what I am actually trying is to connect remotly from a MySQL Client in Windows Subsystem for Linux mysql -h 172.18.0.2 -P 3306 -u root -p and before that I started the Docker Container as follows: docker container run --name testdb --network testnetwork -p 3306:3306 -e MYSQL_ROOT_PASSWORD=mysqlRootPassword -e MYSQL_DATABASE=localtestdb -d mariadb/server.
The purpose why I put the container in a own network, is because I also have a dockerized Spring Boot Application (GraphQL-Server) which shall communicated with this db. But always when I try to connect from my built-in mysql client, in my Windows Subsystem for Linux, with the above shown command. I got the error message: ERROR 2002 (HY000): Can't connect to MySQL server on '172.18.0.2' (115).
What I already tried, to solve the problem on my own is, look up whether the configuration file line (bind-address) is commented out. But it wont work. Interestingly it already worked to set up a docker container with MariaDB and connect from the outside, but now when I try exactly the same, only with the difference that I now put the container in a own existing network, it wont work.
Hopefully there some one out there which is able to help me with this annonying problem.
Thanks!
So far,
Daniel
//edit:
Now I tried the solution advice from a guy from this topic: How to configure containers in one network to connect to each other (server -> mysql)?. Futhermore I linked my Spring Boot (server) application with the "--link databaseContainerName" parameter to the MariaDB container.
Now I am able to start both containers without any error, but I am still not able to connect remotly to the MariaDB container. Which is now running in a virtual docker network with his own subnet.
I explored this recently - this is by design - container isolation. Usually only main (service httpd) host is accessible externally, hiding internal connections (hosts it communicates to deliver response).
Container created in own network is not accessible from external adresses, even from containers in the same bridge but other network (172.19.0.0/16).
Your container should be accessible on docker host address (127.0.0.1 if run locally) and mapped ("-p 3306:3306") port - 3306. But of course it won't work if many running db containers have the same mapping to the same host port.
Isolation is done using firewall - iptables. You can list rules (iptables -L) to see that - from docker host level.
You can modify firewall to allow external access to internal networks. I used this rule:
iptables -A DOCKER -d 172.16.0.0/12 -j ACCEPT
After that your MySQL containerized engine should be accessible using internal address 172.18.0.2 and source (not mapped) port 3306.
Warnings
it disables all isolation, dont't use it on production;
you have to run this after every docker start - rules created/modified by docker on the fly
not every docker container will respond on ping, check it from docker host (linux subsystem in this case) first, from windows cmd later
I used this option (in docker.service) to make rule permanent:
ExecStartPost=/bin/sh -c '/etc/iptables/accept172_16.sh'
For docker on external(shared in lan) host you should use route add (or hosts file on your machine or router) to forward 172.x.x.x addresses into lan docker host.
Hint: use portainer project (with restart policy - always) to manage docker containers. It's easier to see config errors, too.
I have created a image of spring boot gradle project by using command gradlew jibDockerBuild
I run the image by this command docker run -p 8082:8082 demo:0.0.1-SNAPSHOT.Image is running successfully on port 8082.In project application.properties server.port is 8082 only.
I am not able accesss api so I have checked in my machine whether this process is running on the port or not by command netstat -a -n -o | find "8082".No process is running on that port.
When you install Docker on Windows by Docker Toolbox by default Docker will run on 192.168.99.100 IP (DOCKER_IP).
You can access all your containers running inside docker with DOCKER_IP on your Host machine ie Windows.
Read more on it here
Regarding your mapping query
You have mapped port, which means your container port will be mapped to DOCKER_IP:PORT
If you were using Docker on Linux or Mac it will get mapped to localhost:port as in those cases Docker is running on localhost.
The same is not true for Windows at least with Docker Toolbox.
As per your configuration, you can access your application on HOST machine by hitting
http://192.168.99.100:8082
I am running a web application(copied from github examples) that is running as a container in a remote ubuntu VM. The application is a Node JS application that is using mysql database. I brought the application up using docker-compose in ubuntu.
The application came up as http://172....:3000 using a network port. The ip address is displayed in the docker-compose terminal. In the ubuntu system, when i do curl http://172....:3000, it gives a proper success response. The ip address is a container network address. It is not the VM's ip address. There is no firewall.
How to access the web application from my windows 7 machine. When I tried accessing using http://VM Ip address:3000, it is not hitting ubuntu system. I am not getting any message in the docker-compose terminal. Can anyone help here ?
ports:
- "3031:3000"
similar line in your docker compose means you have published port 3000 of your container to port 3031 of your Ubuntu VM.
now you can access your client service as http://<ubuntu-ip>:3031 but before this, you need to allow access to port 3031
According to the docker documentation here
https://docs.docker.com/network/host/
The host networking driver only works on Linux hosts, and is not supported on Docker for Mac, Docker for Windows, or Docker EE for Windows Server.
On Mac what alternatives do people use?
My scenario
I want to run a docker container that'll host a micro-service
The micro-service has dependencies upon databases that I'm also running via docker
I thought I'd be able to use --net=host on Mac when running the micro-service
But the micro-service port is not exposed
I can override the db addresses (they default to localhost) on the microservice.
But that involves robust --env usage
What's the simplest / most elegant solution?
The most simple and most elegant solution is to use docker named bridge network.
You can create a custom bridge network (default is bridge) like this:
docker network create my-network
Every container deployed inside this network can communicate with each other by using the container name.
$ docker run --network=my-network --name my-app ...
$ docker run --network=my-network --name my-database...
In the example above you can connect to your database from inside your application by using my-database:port. If the container port is exposed in the Dockerfile you don't need to map it on your host and you can keep all your communication internal inside your custom docker bridge network.
In most cases the application its port is mapped (example: -p 80:80) so localhost:80 is mapped on container:80 and you can access the app from on your localhost. If the app needs to communicate with a db you don't need to expose the port of the db and you don't have to map it on localhost as explained already above.
Just keep the communication between app and db internal in your custom bridge network.