I have a cassandra image that is listening in port 9042, but since I´m running that image in a virtual machine where has limited external ports I need to map that port to another port.
I try run linking the external port 7017 linked with internal container port 9042 bur it does not work when I run the container and I do a curl
docker run --name cassandra -p 9042:7017 -p 9160:9160 --memory=3000m -d cassandra
In the other way around
docker run --name cassandra -p 9042:7017 -p 9160:9160 --memory=3000m -d cassandra
Any idea how can I map the internal with external port of the container?.
Regards
Related
In my workplace docker is running behind firewall, only the port that is meant to serve webpage is excluded by rule.
The container starts but website does not open for same port.
If I host the website from machine running container using python -m SimpleHTTPServer it works.
docker container run --restart=always -p 8081: 8082 -it vue-js-app: latest
From the Docker documentation:
Publish or expose port (-p, --expose)
$ docker run -p 127.0.0.1:80:8080/tcp ubuntu bash
This binds port 8080 of the container to TCP port 80 on 127.0.0.1 of
the host machine. You can also specify udp and sctp ports. The Docker
User Guide explains in detail how to manipulate ports in Docker.
$ docker run --expose 80 ubuntu bash
This exposes port 80 of the container without publishing the port to
the host system’s interfaces.
And, from the Docker User Guide:
You also saw how you can bind a container’s ports to a specific port
using the -p flag. Here port 80 of the host is mapped to port 5000 of
the container:
$ docker run -d -p 80:5000 training/webapp python app.py
So, as an example of how to expose the ports you can use:
docker container run --restart always -p 8081:8082 -it vue-js-app:latest
I'm having a rather awful issue with running a Redis container. For some reason, even though I have attempted to bind the port and what have you, it won't expose the Redis port it claims to expose (6379). Obviously, I've checked this by scanning the open ports on the IP assigned to the Redis container (172.17.0.3) and it returned no open ports whatsoever. How might I resolve this issue?
Docker Redis Page (for reference to where I pulled the image from): https://hub.docker.com/_/redis/
The command variations I have tried:
docker run --name ausbot-ranksync-redis -p 127.0.0.1:6379:6379 -d redis
docker run --name ausbot-ranksync-redis -p 6379:6379 -d redis
docker run --name ausbot-ranksync-redis -d redis
docker run --name ausbot-ranksync-redis --expose=6379 -d redis
https://gyazo.com/991eb379f66eaa434ad44c5d92721b55 (The last container I scan is a MariaDB container)
The command variations I have tried:
docker run --name ausbot-ranksync-redis -p 127.0.0.1:6379:6379 -d redis
docker run --name ausbot-ranksync-redis -p 6379:6379 -d redis
Those two should work and make the port available on your host.
Obviously, I've checked this by scanning the open ports on the IP assigned to the Redis container (172.17.0.3) and it returned no open ports whatsoever. How might I resolve this issue?
You shouldn't be checking the ports directly on the container from outside of docker. If you want to access the container from the host or outside, you publish the port (as done above), and then access the port on the host IP (or 127.0.0.1 on the host in your first example).
For docker networking, you need to run your application listening on all interfaces (not localhost/loopback). The official redis image already does this, and you can verify with:
docker run --rm --net container:ausbot-ranksync-redis nicolaka/netshoot netstat -lnt
or
docker run --rm --net container:ausbot-ranksync-redis nicolaka/netshoot ss -lnt
To access the container from outside of docker, you need to publish the port (docker run -p ... or ports in the docker-compose.yml). Then you connect to the host IP and the published port.
To access the container from inside of docker, you create a shared network, run your containers there, and access using docker's DNS and the container port (publish and expose are not needed for this):
docker network create app
docker run --name ausbot-ranksync-redis --net app -d redis
docker run --name redis-cli --rm --net app redis redis-cli -h ausbot-ranksync-redis ping
I'm new using docker.
I was asking me if is possible to run many containers on the same aws ec2 instance, triggering all port of the containers on one sigle port on the ec2 instance.
Suppose that we have 3 container:
container1 that run apache2 on port 80
container2 that run nginx on port 80
container3 with tomcat on port 8080
How can access to these services from my pc?
To do this I read that I need to expose ports by typing option -p externport : containerport but its not working
so i thought to change network and then I use option --network=host to trig all port to the same ip but it doesn't work.
I'd like just to accesso to these container in this way:
my-ec2-instance-public-dns:8080 -> container1
my-ec2-instance-public-dns:8081 -> container2
my-ec2-instance-public-dns:8082 -> container3
Can anyone help me?
It is not possible to map two services to the same port. You can map container ports to host ports using the -p flag, formatted hostPort:containerPort when you use container networking mode.
In your case, it could be
docker run -p 8080:80 nginx
docker run -p 8081:80 apache2
docker run -p 8082:8080 tomcat
Make sure you set the AWS security group of your virtual machine to allow traffic from your IP to ports 8080-8082.
I've installed docker in a VM which is publicy available on internet. I've installed mongodb in a docker container in the VM.Mongodb is listening on 27017 port.
I've installed using the following steps
docker run -p 27017:27017 --name da-mongo -v ~/mongo-data:/data/db -d mongo
The port from container is redirected to the host using the -p flag. But the port 27017 is exposed on the internet. I don't want it to happen.
Is there any way to fix it?
Well, if you want it available for certain hosts then you need a firewall. But, if all you need is it working on localhost (your VM machine), then you don't need to expose/bind the port with the host. I suggest you to run the container without the -p option, then, run the following command:
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' your_container_id_or_name
After that, it will display an IP, it is the IP of the container you've just ran (Yes, docker uses somewhat an internal virtual network connecting your containers and your host machine between them).
After that, you can connect to it using the IP and port combination, something like:
172.17.0.2:27017
When you publish the port, you can select which host interface to publish on:
docker run -p 127.0.0.1:27017:27017 --name da-mongo \
-v ~/mongo-data:/data/db -d mongo
That will publish the container port 27017 to host interface 127.0.0.1 port 27017. You can only add the interface to the host port, the container itself must still bind to 0.0.0.0.
I am really confused about this problem. I have two computer in our internal network. Both computers can ping internal servers.
Both computers have same docker version.
I run simple docker container with docker run -it --rm --name cont1 --net=host java:8 command on both computers. Then ssh into containers and try to ping internal server. One of the container can ping an internal server but other one can't reach any internal server.
How it can be possible? Do you have any idea about that?
Thank you
connect container to other systems in the same network is done by port mapping .
for that you need to run docker container with port mapping.
like - docker run -it --rm --name cont1 -p host_ip:host_port:container_port java:8
e.g., docker run -it --rm --name cont1 -p 192.168.134.122:1234:1500 java:8
NOTE : container port given in docker run is exposed in Dockerfile
now for example container ip will be - 172.17.0.2 port given in run is :1500
Now the request send to host_ip(192.168.134.122) and host_port(1234) is redirect to container with ip (172.17.0.2) and port (1500).
See the binding details in iptables -L -n -t nat
Thanks