i have my web app created using react inside a container and its running smoothly but when i want to access the localhost after binding contaienr port to mine its doesnt work but if i run the app without docker its working fine
this is he **dockerfile **
**
container logs **
docker build -t my-react-app .
docker run --name test -p 80:5173 my-react-app
The app is only accessible from within the container itself, not from the host machine. This is because localhost refers to the loopback interface, which is only accessible from within the container.
If you want to make the app accessible from the host machine, you need to set the HOST environment variable to 0.0.0.0 instead of localhost. This tells the app to listen on all available network interfaces, including the loopback interface.
You can set the HOST environment variable to 0.0.0.0 in your Dockerfile like this:
# set the host
ENV HOST=0.0.0.0
# run the app
CMD ["npm", "dev"]
Then, when you run the container, you can bind it to a specific host and port using the -p flag. This will start the React app and bind it to the host's port you specified, so you should be able to access it from your host machine by visiting http://localhost:5173 in your web browser.
Related
I have a docker image with some ruby on rails environment built in (i.e. installing some rails gems and system packages) and I have an EXPOSE 3000 to expose the port at the end.
I ran a container with docker run -p 3000:3000 -ti <image> bash, then start the rails server. The logs are saying the web server is available on localhost:3000. I tried to connect to both the IPAddress as specified in docker inspect <id> and localhost on my host machine, but neither would be able to connect. What could be the problem here?
If your application is listening on localhost, it will only respond to requests from the container's localhost - that is, other processes inside the container.
To fix this you need to set the listen address of your server to listen to any address (usually, you specify this as 0.0.0.0). I've never used rails, but from a quick search, you should use the -b option.
So changing your ENTRYPOINT or CMD in your Dockerfile to contain -b 0.0.0.0 would probably do it.
I have an app running inside a docker container on localhost:4200 (not 0.0.0.0:4200). How can I expose it to the host?
When I use -p 4200:4200 on docker run, I am not able to get to the app.
i.e. curl localhost:4200 or curl http://127.0.0.1:4200 or curl http://<ip from ifconfig>:4200 or curl http://0.0.0.0:4200 doesn't work.
However, docker exec <container-id> curl localhost:4200 works. This means that app started successfully but 4200 port on localhost from container is not exposed to the host.
I stopped the app and modified the app (on the same running container) to expose the app on 0.0.0.0:4200 instead of localhost:4200. After that, I am able to get to curl http://0.0.0.0:4200.
I am trying to figure out on how can I expose the port on localhost from container to host (so that I don't have to modify my app).
You can be more explicit and use:
docker run --publish=127.0.0.1:4200:4200/tcp ....
See documentation
However:
127.0.0.1 corresponds to your host's loopback adaptor
0.0.0.0 is effectively any network adaptor on this host (including 127.0.0.1)
localhost is the DNS name that is customarily mapped to 127.0.0.1
So the consequence should be the same regardless of which of these approaches you use.
HTH!
I built a container with a react app within it.
I start the app.. docker run -p 3000:3000 blarg3/node
I can bash into the container and curl localhost:3000 and it returns the front page of my site.
When I go to the IP and port http://172.17.0.2:3000/. Nothing is returned.
By default "docker run" binds port only to local interface. If you want to bind it to another interface you need to specify it's IP address like this:
docker run -p 172.17.0.2:3000:3000 blarg3/node
You can read more about docker networking options here: https://docs.docker.com/engine/userguide/networking/default_network/dockerlinks/#connect-using-network-port-mapping
I have two services running in separate containers, one is grunt(application) and runs off port 9000 and the other is sails.js (server) which runs off port 1337. What I want to try to do is have the client app connect with the server through localhost:1337. Is this feasible? Thanks.
HOST
You won't be able to connect to the other container with localhost (as localhost is the current container) but you can connect via the container host (the host that is running your container). In your case you need boot2docker VM IP (echo $(boot2docker ip)). For this to work, you need to expose your port at the host level (which you are doing with -p 1337:1337).
LINK
Another solution that is most common and that I prefer when possible, is to link the containers.
You need to add the --name flag to the server docker run command:
--name sails_server
You need to add the --link flag to the application docker run command:
--link sails_server:sails_server
And inside your application, you will be able to access the server at sail_server:1337
You could also use environment variables to get the server IP. See documentation: https://docs.docker.com/userguide/dockerlinks/
BONUS: DOCKER-COMPOSE
Your run commands may start to be a bit long... in this case I like to use docker-compose that allows me to define my containers and their relationships (volumes, names, link, commands...) in one file.
Yes if you use docker parameter -p 1337:1337 in your docker run command, it will expose the port 1337 from inside the container to your localhost:1337
I have a Rails app deployed with Dokku on DigitalOcean. I've created a Postgres database and linked it with a Rails app. Everything worked fine until I restarted the droplet. I figured out that apps stopped working because on restart every Docker container gets a new port and Rails application isn't able to connect to it. If I run dokku postgresql:info myapp it shows the old port, but it has changed. If I manually change database.yml and push it to the dokku repo everything works.
So how do I prevent Docker from assigning different port each time the server restarts? Or maybe there is an option to change ports of running containers.
I don't have much experience with Dokku but for docker there's no such thing of A container's port.
In docker you can expose a container's port to receive incoming request and map it to specific ports in your host machine.
With that you can, for instance, run your postgres inside a container and tell docker that you wanna expose the 5432, default postgresql port, to receive incoming requests:
sudo docker run --expose=5432 -P <IMAGE> <COMMAND>
The --expose=5432 tells docker to expose the port 5432 to receive incoming connections from outside world.
The -P flag tells docker to map all exposed ports in your container to the host machine's port.
with that you can connect to postgres pointing to your host's ip:port.
If you want to map a container's port to a different host machine port you can use the -p flag:
sudo docker run --expose=5432 -p=666 <IMAGE> <COMMAND>
Not sure if this can help you with Dokku environment, but I hope so.
For more information about docker's run command see: https://docs.docker.com/reference/commandline/cli/#run