How to map an application port number to the docker container port number?

Published August 8, 2021

To map the application or the host port number to the docker container port number, you can use the docker run command followed by the -p flag (port number flag) and then the docker port number followed by a : (colon) and then the application port number and then the name of the docker image to use.

TL;DR

# Map application or host port number
# to docker container port number
docker run -p <DOCKER_PORT_NUMBER>:<APPLICATION_PORT_NUMBER> docker/getting-started


# Example:
# --------

# docker run -p 3000:80 docker/getting-started

For example, let's say we want to run a docker container on port 3000 in which the original application port number is running on port number 80.

To do that we can use the docker run command like this,

# Map application or host port number
# to docker container port number
docker run -p 3000:80 docker/getting-started

• After running the above command the docker container which is using the docker/getting-started image can be accessible at localhost:3000 even though the original application port number is 80.

And like that, we have successfully mapped the docker container port number to the application or the host port number 🎉.

If you want to try out the docker commands online, see the Play with docker lab website to test out the commands.

That's all 😃!

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