I build a very simple web app and web api on .net core and configured the docker-compose to get them to communicate over the same network correctly.
On visual studio, when I hit play on the Docker Compose project, it runs fine, both the web app and the web api work and communicate correctly.
On the Docker Desktop app i see them running (green).
But when I close/stop the debugger on VS I can't access the websites anymore even though the containers are still running. I thought docker worked as a sort of IIS.
Am I misunderstanding the docker capabilities or do I need to run them again from a CLI or publish them somewhere or what?
I thought the fact the containers are up and running should mean they're live for me to navigate to.
Help me out over here please.
You are correct, unless there is some special routing happening, the fact that the containers are running means your services are available.
You can see the ports being exposed from the docker ps -a command:
CONTAINER_ID: 560f78689902
IMAGE: moviedecisionweb:dev
COMMAND: "C:\\remote_debugger\\…"
CREATED: About a minute ago
STATUS: Up About a minute
PORTS: 0.0.0.0:52002->80/tcp, 0.0.0.0:52001->443/tcp
NAMES: mdweb
CONTAINER_ID: 1cd7f72426fe
IMAGE: moviedecisionapi:dev
COMMAND: "C:\\remote_debugger\\…"
CREATED: About a minute ago
STATUS: Up About a minute
PORTS: 0.0.0.0:52005->80/tcp, 0.0.0.0:52004->443/tcp
NAMES: mdapi
Based on the provided output, you have two docker containers running.
I'm assuming the ports 80 & 443 are serving the HTTP & HTTPS services (respectively) from your app/s.
Based on this...
For container "mdweb", you should be able to access the docker services from your docker host machine (PC) via:
http://0.0.0.0:52002
https://0.0.0.0:52001
For container "mdapi", you should be able to access the docker services from your docker host machine (PC) via:
http://0.0.0.0:52005
https://0.0.0.0:52004
I believe you can use localhost, 127.0.0.1 & 0.0.0.0 interchangeably in the above.
You cannot use the hostnames "mdweb" or "mdapi" from your docker HOST machine - unless you have explicitly setup your DNS to handle these names. However you can use these hostnames if you are inside a docker container on the same docker network.
If you provide more information (e.g. your docker-compose.yml), we could help you further...
Related
I have two containers it was builded with command > docker-compose up --build -d.
All containers build normally and stays up, but when I leave the machine the containers stays up at least 2 hours until que he drops again.
This containers is running an API in PHP LARAVEL Framework and a nginx reverse proxy.
Docker Image Started as 46Hours ago and UP 2 seconds
When I start the application and leave the machine where Docker is installed, it is in max two hours running. If I access the machine via ssh and then after that access the application and it is running without the need to do a docker-compose up. And the api was written in Laravel PHP with a Nginx container making a reverse Proxy.
What do I have to do to make these containers stand up as a productive environment?
There is a command that can help you when it goes down or stops:
sudo docker run --restart unless-stopped --name <Name you want to use> <Name of your container>
don't use these <> in your command
after doing this anytime that container is down it will restart the container for you automatically.
I think this trick is really useful when you have multiple containers running, and helpful when you want to update the server packages too.
Environment: VS2019 on Windows 10
I have created a core asp.net project.
Right clicked on the project and added orchestration support.
Selected Docker compose.
Target OS: Linux
With this I ran docker ps and got the following output
I hit F5 in VStudio and the browser opens with https://localhost:32776 and shows the web page
I now run docker inspect 9e1911ce311a and get the following output
Problem:
Since the docker ip here in this case is 172.20.0.3, why does https://172.20.0.3:32776 result in
Short Answer:
Host Machine:
URL: http://localhost:32776/
Inside Docker:
URL: https://172.20.0.3/
docker -it <container id> bash
curl https://172.20.0.3/
Long Answer:
When working on docker there are always 2 networks host machine network docker's own private network
docker network ls
For a port mapping --ports <left side>:<right side>
if you are debugging from withing docker container you'll have to use port on the right side of the mappings. If you are accessing from host machine use the one of the left hand side.
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 a spring-config-sever project that I am trying to run via Docker. I can run it from the command line and my other services and browser successfully connect via:
http://localhost:8980/aservice/dev
However, if I run it via Docker, the call fails.
My config-server has a Dockerfile:
FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE=build/libs/my-config-server-0.1.0.jar
ADD ${JAR_FILE} my-config-server-0.1.0.jar
EXPOSE 8980
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/my-config-server-0.1.0.jar"]
I build via:
docker build -t my-config-server .
I am running it via:
docker run my-config-server -p 8980:8980
And then I confirm it is running via
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
1cecafdf99fe my-config-server "java -Djava.securit…" 14 seconds ago Up 13 seconds 8980/tcp suspicious_brahmagupta
When I run it via Docker, the browse fails with a "ERR_CONNECTION_REFUSED" and my calling services fails with:
Could not locate PropertySource: I/O error on GET request for
"http://localhost:8980/aservice/dev": Connection refused (Connection
refused);
Adding full answer based on comments.
First, you have to specify -p before image name.
docker run -p 8980:8980 my-config-server.
Second, just configuring localhost with host port won't make your my-service container to talk to other container. locahost in container is within itself(not host). You will need to use appropriate docker networking model so both containers can talk to each other.
If you are on Linux, the default is Bridge so you can configure my-config-server container ip docker inspect {containerIp-of-config-server} as your config server endpoint.
Example if your my-config-server ip is 172.17.0.2 then endpoint is - http://172.17.0.2:8980/
spring:
cloud:
config:
uri: http://172.17.0.2:8980
Just follow the docker documentation for little bit more understanding on how networking works.
https://docs.docker.com/network/network-tutorial-standalone/
https://docs.docker.com/v17.09/engine/userguide/networking/
If you want to spin up both containers using docker-compose, then you can link both containers using service name. Just follow Networking in Compose.
I could imagine that the application only listens on localhost, ie 127.0.0.1.
You might want to try setting the property server.address to 0.0.0.0.
Then port 8980 should also be available externally.
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.