Separate ordinary environment configuration from files and secrets, inject values at the correct boundary, and prevent sensitive data from entering image history.
Intermediate14 min read
Docker lessonContainer and orchestration foundationsPractice
UNTIMED COACHING
Practice before the pressure
Use feedback to correct the model, not merely memorize an option position.
GUIDED PRACTICE
Practice the lesson questions
Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.
20 questions balanced across the lesson's key topics
At least four explanatory diagrams or tables
Retry freely, without a timer or score
CONCEPT MODELS
See the lesson as a system
Use these visual guides to connect the key ideas before answering the questions.
Connect the roles in Environment Variables, Configs, and SecretsKeep environment value, configuration file, secret material, and injection step as separate workload roles.Verify Exposure boundaryConnect exposure boundary with its topic-specific inspection, expected outcome, and protected workload boundary.