Docker & Containers

What: Container workflow: Image vs container is used to build, run, inspect or manage isolated application environments. Confirm image names, ports and mounted paths before running. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study Image vs container in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: Image vs container

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: isolation: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study isolation in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: isolation

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: layers: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study layers in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: layers

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: registries: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study registries in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: registries

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: lifecycle: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study lifecycle in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: lifecycle

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: pull: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study pull in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: pull

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: run: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study run in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: run

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: Linux command ps: a practical CLI building block. Use it in a terminal, review the output before changing files or services, and check ps --help for supported options. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study ps in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: ps aux

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: logs: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study logs in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: logs

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: exec: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study exec in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: exec

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: stop: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study stop in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: stop

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: Linux command rm: a practical CLI building block. Use it in a terminal, review the output before changing files or services, and check rm --help for supported options. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study rm in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: rm -i file.txt

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: images: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study images in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: images

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: inspect: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study inspect in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: inspect

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: Container workflow: Dockerfile is used to build, run, inspect or manage isolated application environments. Confirm image names, ports and mounted paths before running. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study Dockerfile in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: Dockerfile

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: build context: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study build context in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: build context

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: tags: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study tags in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: tags

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: ports: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study ports in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: ports

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: environment: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study environment in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: environment

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: volumes: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study volumes in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: volumes

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: compose.yaml: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study compose.yaml in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: compose.yaml

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: Container workflow: multi-container apps is used to build, run, inspect or manage isolated application environments. Confirm image names, ports and mounted paths before running. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study multi-container apps in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: multi-container apps

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: networks: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study networks in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: networks

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.

What: volumes: a practical computer skill. Learn the purpose, core concept, syntax or workflow, real-world use cases, prerequisites, common mistakes, troubleshooting path, security implications, and related advanced concepts. Start with a safe read-only example, verify the result, then move to automation or administration only when you understand the side effects. Docker & Containers: understand images, layers, containers, ports, mounts, networks, registries, Dockerfiles and Compose. Separate ephemeral container state from persistent data. Study volumes in four passes: (1) purpose and vocabulary, (2) mechanism or syntax, (3) a safe practical example, and (4) verification plus troubleshooting. For every exercise, record the starting state, action, expected result, actual result and recovery step. This turns memorization into a repeatable professional workflow.

Why it matters: Connect this skill to the module goal, identify its inputs and expected output, and note what could go wrong if the wrong target, permission, format or context is used.

How to learn it: Observe the starting state → perform the smallest safe example → inspect the result → change one variable → repeat and explain the difference.

Example: volumes

Professional check: verify the result independently instead of assuming a command, shortcut or setting succeeded.