Docker Essentials

Explore the architecture of Docker, including the Docker client, host, and registry, and how the Docker daemon builds images from Dockerfiles and runs containers via CLI and APIs.

Explore Docker Hub, a cloud-based service to build, link, and manage docker images with automated builds. Explore popular repositories and the community, including nginx, from the dashboard.

Compare docker container create and run using busybox, with interactive -it and detached -d flags and --rm; observe container IDs and statuses via docker ps -a.

Learn to manage containers using docker commands: start, stop, restart with a 5-second delay, and rename cc-busybox containers, verify status with docker ps -a, and note the rm flag consequences.

Demonstrate port mapping by binding host port 8080 to container port 80 with -p TCP, show how -P maps ports via EXPOSE, and verify nginx on localhost:8080.

Learn to remove docker containers by listing them and using rm with names or IDs, force deleting running containers, or docker container kill, then prune stopped containers to free resources.

Connect a running container to user-defined and default docker bridge networks, verify connections with docker inspect, observe endpoint IDs and IP addresses like 172.17.0.2, and disconnect as shown.

Explore how docker volumes, bind mounts, and tmpfs mounts provide persistent and secure storage for containers, and understand how read-only and read-write layers influence what to back up.

Learn how docker compose defines and runs multi-container applications from a single file, coordinating containers, networks, and services with one command, simplifying complex docker engine setups.

Run docker-compose up to launch wordpress and mysql, creating the default bridge network and wordpress_files and db_data volumes, with db starting before wordpress and 8000 mapped to 80.

Learn how Docker Swarm coordinates containers across multiple hosts with a manager–worker cluster, delivering services with replicas and tasks via orchestrator, dispatcher, scheduler, and executor.

Create and manage swarm nodes using docker-machine with boot2docker on VirtualBox, launching a manager and workers, inspecting nodes, and connecting to the manager via ssh.

Initialize a docker swarm on the manager with docker swarm init and advertise its IP. Then join worker-1 and worker-2 to the swarm using docker swarm join and the token.

Verify swarm membership by listing nodes with docker node ls and inspecting each node with docker node inspect to view IDs, hostnames, status, platform, resources, and engine version 18.06.1 CE.

Drain a node in swarm for maintenance, transferring tasks to other nodes. Verify with Docker node ls and Docker service ps, then leave the swarm to remove the node.

Demonstrates scaling a swarm service from 3 to 6 replicas with docker service scale, updating to nginx:alpine, verifying with docker service inspect, and cleaning up by removing the service.