Docker · Reference

Pull, tags, logs cheat sheet

Compressed facts from lesson 0002. Keep open while debugging.

Jobs

Command Does
docker pull Download image only (no container)
docker run Create + start container (pull if missing)
docker image ls List local packages (name + tag)
docker logs Container stdout / stderr

Tags

name:tag          # e.g. nginx:alpine, node:22
name              # same as name:latest
latest            # default label — can move; not “magic newest forever”
@sha256:…         # digest pin (immutable; later)

Commands

# Download package
docker pull nginx:alpine

# What’s local?
docker image ls

# Run from a known tag
docker run -d -p 8080:80 --name lesson2 nginx:alpine

# Debug loop
docker ps
docker logs lesson2
docker logs --tail 20 -f lesson2   # Ctrl+C stops follow only

# Clean container (image stays)
docker stop lesson2
docker rm lesson2

Debug order of attack

  1. docker ps / docker ps -a — is it running or exited?
  2. docker logs name — why did it fail or misbehave?
  3. docker image ls — which name:tag did we actually run?

From lesson 0002 · Sources: image docs, pull, logs