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

August 8, 2021 - 2 min read

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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