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Multiple ports

Learn to map multiple ports.

Multiple ports

A container can publish several ports; a separate -p is written for each. Ranges are supported too:

docker run -d --name web -p 80:80 -p 443:443 nginx
docker run -d -p 7000-7005:7000-7005 kume-dugumu

In services like RabbitMQ one port is for application traffic and the other for the management UI: -p 5672:5672 -p 15672:15672.

Looking at all ports

docker port can also query a single container port. docker inspect gives the mappings as JSON:

$ docker port web 443
0.0.0.0:443
$ docker inspect -f '{{json .NetworkSettings.Ports}}' web
{"443/tcp":[{"HostIp":"0.0.0.0","HostPort":"443"}],"80/tcp":[{"HostIp":"0.0.0.0","HostPort":"80"}]}

Practice RabbitMQ

Start a container named mq from the rabbitmq:3-management image in the background; publish ports 5672 and 15672 on the host with the same numbers.

Starter code

terminal
# buraya yaz

Expected output

e5f6a7b8c9d0

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What is done to publish HTTP and HTTPS from the same container?

  • Two separate -p flags are written Correct answer
  • -p 80,443 is written
  • Two containers are opened
  • It isn't possible

Explanation: Each mapping is a separate -p.

2 Publish a port range.

Question 
docker run -d -p 7000____:7000-7005 kume-dugumu
Answer 
docker run -d -p 7000-7005:7000-7005 kume-dugumu

Explanation: A range is written with a dash and must be the same length on both sides.

3 Match.

Term Meaning
-p 80:80 -p 443:443 Two separate mappings
7000-7005 Port range
docker port web 443 Single port query
15672 Management UI

All lessons in Beginner

1 What is Docker?

  1. What is Docker?
  2. Containers and virtual machines
  3. Images and containers
  4. Docker architecture
  5. Use cases
  6. Summary - What is Docker

2 Installation and first commands

  1. Installing Docker
  2. docker version
  3. docker info
  4. The hello-world container
  5. Docker Desktop
  6. Summary - Installation

3 First container

  1. docker run basics
  2. Running in the background
  3. docker ps
  4. docker stop and rm
  5. docker logs
  6. Summary - First container

4 Dockerfile basics

  1. What is a Dockerfile?
  2. The FROM instruction
  3. The RUN instruction
  4. COPY and ADD
  5. CMD and ENTRYPOINT
  6. Summary - Dockerfile

5 Build and images

  1. docker build
  2. Tagging images
  3. Build context
  4. Layers and cache
  5. .dockerignore
  6. Summary - Build

6 docker run options

  1. Interactive mode
  2. Naming containers
  3. Restart policy
  4. Working directory
  5. Switching users
  6. Summary - docker run

7 Image management

  1. docker images
  2. docker rmi
  3. docker pull
  4. docker push
  5. docker tag
  6. Summary - Image management

8 Port mapping

  1. The port concept
  2. The -p flag
  3. Multiple ports
  4. Random ports
  5. IP binding
  6. Summary - Port mapping

9 Volumes and data

  1. Data persistence
  2. Named volumes
  3. The -v flag
  4. Bind mounts
  5. Volume management
  6. Summary - Volumes

10 Environment variables

  1. The -e flag
  2. The ENV instruction
  3. The ARG instruction
  4. env-file
  5. The WORKDIR instruction
  6. Summary - Environment

11 Project: docker-compose

  1. Compose design
  2. Service definition
  3. Database service
  4. Volume and network
  5. Putting it together - compose

12 Docker Hub and registry

  1. What is Docker Hub?
  2. docker login
  3. Searching images
  4. Official images
  5. Private registry
  6. Summary - Registry

13 Network basics

  1. Network drivers
  2. docker network ls
  3. Bridge network
  4. Container connectivity
  5. Publishing ports
  6. Summary - Network

14 Beginner final

  1. Challenge - Dockerfile
  2. Challenge - Build and run
  3. Challenge - Volume
  4. Challenge - Compose
  5. Challenge - Beginner project