What is difference between expose and publishing?

Short answer: EXPOSE is a way of documenting. –publish (or -p ) is a way of mapping a host port to a running container port.

What does expose in Docker do?

The EXPOSE instruction exposes a particular port with a specified protocol inside a Docker Container. In the simplest term, the EXPOSE instruction tells Docker to get all its information required during the runtime from a specified Port. It does not map ports on the host machine.

What is the difference between expose and ports Docker?

Expose is defined as: Only the internal port can be specified. Ports are not exposed to host machines, only exposed to other services.

What is publishing a port?

Expose means to open the port on the container side, publish means to open it on the Docker host to the outside world. For example, if your docker run command had -p 80:8080, it’s exposing port 8080 on the container and publishing port 80 on the host.

Does Docker expose default ports?

The answer: Docker does not expose ports by default, you have to configure every exposed port yourself! As a developer, some Docker concepts are more difficult to understand than others.

How do I publish a port?

How to Expose Ports in Docker

1. Add an EXPOSE instruction in the Dockerfile.
2. Use the –expose flag at runtime to expose a port.
3. Use the -p flag or -P flag in the Docker run string to publish a port.

How do I publish port Docker?

How do I expose Docker container ports?

What is Docker port?

Advertisements. In Docker, the containers themselves can have applications running on ports. When you run a container, if you want to access the application in the container via a port number, you need to map the port number of the container to the port number of the Docker host.

How do you expose a port?

You can expose a port through your Dockerfile or use –expose and then publish it with the -P flag. This will bind the exposed port to your Docker host on a random port (verified by running docker container ls ). You can expose a port through your Dockerfile or use –expose and then publish it with the -p 80:80 flag.

How do you expose a container?

You can use SSH to create a tunnel and expose your container in your host. You can do it in both ways, from container to host and from host to container. But you need a SSH tool like OpenSSH in both (client in one and server in another).