Docker in depth
The operator's course. How images are put together, building with BuildKit and Buildx (cache, secrets, multi-platform), what the engine is made of and how to configure it, the containerd image store and volumes, the network model down to the packet path and nftables, Swarm in three lessons, worked recipes for databases, Redis, Python, NGINX and WordPress, and a CI pipeline that builds, signs and promotes one digest. Twenty-four lessons across eight sections, every command run on Docker Engine 29.8.2 in the lab VMs.
01Image anatomy: index, manifest, config and layersWhat an image is on the wire and on disk.16 min02Tags, digests and promotionMutable tags, immutable digests and promoting by digest.14 min03Inspecting, exporting and cleaning up imagesimage ls on Docker 29, save and load, disk usage and pruning.20 min
01BuildKit builds: stages, cache and mountsMulti-stage builds, parallel stages, cache, bind, secret and SSH mounts.15 min02Buildx builders, outputs, cache and BakeBuilders and drivers, --load and --push, cache export and Bake files.16 min03Multi-platform imageslinux/amd64 and linux/arm64 from one build: emulation, cross-compiling and indexes.15 min
01Engine architecture on Docker 29CLI, dockerd, containerd, the shim and runc, and what each owns on Docker 29.12 min02Configuring the daemon safelydaemon.json, what to leave alone, and how to change it without surprises.20 min03Logging and log driversjson-file, local and journald, rotation, remote drivers and the dual-logging cache.13 min
01Networks, drivers and DNSBridges, veth pairs, the embedded DNS server, internal networks, ipvlan and legacy links.15 min02Publishing ports and the packet pathFrom a client to a container and back: NAT, docker-proxy, IPv6, firewalls and the nftables backend.30 min03Network troubleshootingA method for 'it cannot connect', with nsenter, tcpdump, rule counters and conntrack.16 min
01Swarm clusters and servicesManagers, Raft quorum, join tokens, services, rolling updates, rollback and autolock.30 min02Stacks, secrets and configsDeploy a Compose file to a swarm, with private images, secrets and configs that rotate.25 min03Overlay networks and the routing meshVXLAN overlays, VIP vs DNS round robin, the ingress mesh, host mode and encryption.18 min
01Recipe: a Python web appA slim, non-root, hash-locked image for a WSGI app.13 min02Recipe: PostgreSQL, MySQL and MongoDBData volumes, secret files, init scripts, health checks, backup and upgrades.22 min03Recipe: RedisCache or datastore: persistence, memory limits and ACL users.14 min04Recipe: NGINX as a reverse proxyTLS edge, static files, proxying, and re-resolving names after a backend moves.14 min05Recipe: WordPress and MySQL with secretsTwo services, secrets WordPress can read, health checks, and a tested backup.14 min
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Quick reference
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Final exam
Test yourself on everything
40 questions drawn from all 8 sections — every answer explained as you pick.