Docker Essentials Flashcards (copy)

Vocabulary flashcards for Docker essentials.

Docker Image

A lightweight, standalone, and executable software package that includes everything needed to run a piece of software, including the code, runtime, libraries, and dependencies.

Docker Container

A runtime instance of a Docker image. It includes the application and its dependencies but runs as an isolated process on the host operating system.

Docker Image vs. Container

An image is a read-only template; a container is a running instance of that image with a writable layer on top.

Dockerfile

A text file that contains a series of instructions to build a Docker image automatically.

Docker Compose

A tool to define and manage multi-container Docker applications using a YAML file to configure application services.

Dockerfile commands

FROM, RUN, CMD, COPY, ADD, ENV, EXPOSE, WORKDIR, ENTRYPOINT

FROM instruction

Specifies the base image from which you start building your image.

RUN instruction

Executes commands in a new layer on top of the current image and commits the results.

CMD instruction

Specifies the default command to run when the container starts.

CMD vs. ENTRYPOINT

CMD provides default arguments for ENTRYPOINT or command, while ENTRYPOINT sets the executable that will run.

Docker build, docker run

Common Docker commands to build and run images

docker ps

Lists running containers

docker stop

Stops a running container

docker rm

Removes a container

docker rmi

Removes an image

docker logs

View logs of a container

Docker Networking

Allows containers to communicate with each other and with the outside world.

Default Docker Network Types

bridge (default), host, none

Bridge Network

A private internal network created by Docker to allow communication between containers on the same host.

-p flag in docker run

Exposes ports using Docker, e.g. -p hostPort:containerPort

Services section in docker-compose.yml

Defines services in Docker Compose

Volumes in Docker Compose

To persist data beyond the life of containers by mounting host directories or named volumes.

Basic Structure of docker-compose.yml

version, services, volumes, networks

docker-compose up

Starts containers using Docker Compose

docker-compose down

Stops containers using Docker Compose

docker-compose ps

View running containers in Docker Compose