[Solved] Given this Dockerfile snippet:FROM scratch COPY app /app CMD ["/app"]What will happen when you build and run this container? | Docker

Docker - Image Optimization

Given this Dockerfile snippet:

FROM scratch
COPY app /app
CMD ["/app"]

What will happen when you build and run this container?

AThe container runs but crashes because /app is missing

BThe container fails because scratch has no shell to run commands

CThe container runs an Alpine Linux shell

DThe container runs the app binary copied to /app

Step-by-Step Solution

Solution:

Step 1: Analyze the Dockerfile commands
The Dockerfile copies a binary named 'app' into the root filesystem at /app and sets it as the command to run.
Step 2: Understand scratch behavior
Scratch is empty but can run statically compiled binaries copied into it. Since /app exists, the container runs it.
Final Answer:
The container runs the app binary copied to /app -> Option D
Quick Check:
Scratch runs copied binaries directly [OK]

Quick Trick: Scratch runs only what you copy in [OK]

Common Mistakes:

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