[Solved] A developer wrote this Dockerfile snippet for a Spring Boot app:FROM openjdk:17-jdk-slim COPY target/app.jar /app.jar CMD java -jar /app.jarWhy might this container fail to start? | Spring Boot

Spring Boot - Docker and Deployment

A developer wrote this Dockerfile snippet for a Spring Boot app:

FROM openjdk:17-jdk-slim
COPY target/app.jar /app.jar
CMD java -jar /app.jar

Why might this container fail to start?

AThe jar file must be renamed to app.war

BThe COPY command is missing the source path

CThe CMD instruction should be an array, not a string

DThe base image openjdk:17-jdk-slim is invalid

Step-by-Step Solution

Solution:

Step 1: Check CMD syntax in Dockerfile
CMD should be an array for exec form to avoid shell issues, e.g., ["java", "-jar", "/app.jar"]
Step 2: Verify other instructions
COPY has correct source and destination; base image is valid; jar extension is correct.
Final Answer:
The CMD instruction should be an array, not a string -> Option C
Quick Check:
Docker CMD syntax = Use array form [OK]

Quick Trick: Use array syntax for CMD to avoid shell errors [OK]

Common Mistakes:

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A developer wrote this Dockerfile snippet for a Spring Boot app: