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Beginner 25 min
Docker Deep Dive
Images, containers, Dockerfiles, volumes, networking - everything you need to containerize your first app.
“It worked on my machine' is a DevOps joke until Docker makes it true.”
What you'll learn
Images & layersDockerfilesVolumes & mountsNetworkingCompose
Docker images are layered filesystems. Each instruction in a Dockerfile creates a new layer. Cache layers by ordering instructions from least to most frequently changing - package.json before source code, so npm install only re-runs when dependencies change.
Multi-stage builds: use one stage to compile/build and a second, smaller stage to run. The Go/Node/Rust compiler goes in the build stage, only the compiled binary or dist folder goes in production. Cuts image size by 10x.