Working with Docker involves a set of essential CLI commands for building images, running and managing containers, and inspecting/debugging. Knowing them is fundamental, everyday practical knowledge.
docker build -t myapp:1.0 . # build an image from a Dockerfile in the current dir
docker images # list local images
docker pull nginx:latest
docker push myapp:1.0
docker rmi myapp:1.0
docker tag myapp:1.0 myapp:latest
docker run -d -p 8080:80 --name web nginx # run a container (-d background, -p ports, --name)
docker ps # list RUNNING containers
docker ps -a # list ALL containers (including stopped)
docker stop web # stop a container
docker start web # start a stopped container
docker restart web # restart
docker rm web # remove a (stopped) container
docker logs web # view a container's logs
docker logs -f web # follow logs live
docker exec -it web bash # run an interactive shell INSIDE a running container
docker inspect web # detailed info (config, network, mounts) as JSON
docker stats # live resource usage (CPU, memory) of containers
These are key for debugging — logs to see output, exec -it ... bash to get a shell inside a container, inspect for configuration details.
docker system df # disk usage
docker system prune # remove unused data (stopped containers, dangling images)
docker volume ls # list volumes
docker network ls # list networks
Knowing the essential Docker commands is fundamental, everyday practical knowledge for anyone working with Docker, because the CLI is the primary way to build images, run and manage containers, and debug — operations you perform constantly.
The image commands (build, images, pull, push, rmi, tag) handle creating, retrieving, sharing, and versioning images.
The container lifecycle commands (run with its important options like -d for background, -p for port mapping, --name; plus ps, stop, start, rm) are how you run and manage containers day-to-day.
Particularly valuable are the inspection and debugging commands — logs (viewing container output, essential for diagnosing issues), exec -it ... bash (getting an interactive shell inside a running container to investigate, a crucial debugging technique), inspect (detailed configuration), and stats (resource usage) — since debugging containerized applications is a common, important need.
Knowing system and cleanup commands (system prune to reclaim space, listing volumes/networks) is practical for maintenance.
Since the Docker CLI is the universal, constant interface for working with Docker (building, running, managing, and especially debugging containers), and since these commands are used routinely in development and operations, knowing the essential Docker commands is fundamental, frequently-applied knowledge — basic operational competency for anyone using Docker, where the debugging commands (logs, exec, inspect) in particular are invaluable for diagnosing the issues that inevitably arise with containerized applications.