Docker port mapping¶

Docker port mapping is a mechanism that allows services running inside a Docker container to be accessed via ports on the host machine.^[600-developer-docker-docker-compose-docker-compouse-02.md] This creates a connection between a specific port on the host and a specific port inside the container.

Syntax and Configuration¶

Port mappings are typically defined within a service's configuration using the ports section.^[600-developer-docker-docker-compose-docker-compouse-02.md] The syntax follows the format "HOST_PORT:CONTAINER_PORT"^[600-developer-docker-docker-compose-docker-compouse-02.md]:

• Host Port: The port number on the local machine where the service will be accessed.
• Container Port: The port number on which the application inside the container is listening.

Example¶

In the following docker-compose.yml configuration for a MySQL database, the ports attribute maps port 33060 on the host to port 3306 inside the container^[600-developer-docker-docker-compose-docker-compouse-02.md]:

services:
  db:
    image: mysql:5.7
    ports:
      - "33060:3306"

With this configuration, the database can be accessed by connecting to localhost:33060, even though the MySQL process inside the container is running on its default port 3306^[600-developer-docker-docker-compose-docker-compouse-02.md].

Related Concepts¶

• Docker Compose
• [[Docker]]

Sources¶

^[600-developer-docker-docker-compose-docker-compouse-02.md]