buildkit/ConsistentInstructionCasing

Instruction keywords should use consistent casing throughout the Dockerfile.

Property	Value
Severity	Warning
Category	Style
Default	Enabled
Auto-fix	Yes (`--fix`)

Description

Instruction keywords should use consistent casing (all lowercase or all uppercase). Using a case that mixes uppercase and lowercase, such as PascalCase or snakeCase, results in poor readability.

Examples

Bad:

From alpine
Run echo hello > /greeting.txt
EntRYpOiNT ["cat", "/greeting.txt"]

Good (all uppercase):

FROM alpine
RUN echo hello > /greeting.txt
ENTRYPOINT ["cat", "/greeting.txt"]

Good (all lowercase):

from alpine
run echo hello > /greeting.txt
entrypoint ["cat", "/greeting.txt"]

Auto-fix

The fix changes instruction keywords to match the majority casing in the Dockerfile.

# Before (majority is uppercase)
FROM alpine
run echo hello

# After (with --fix)
FROM alpine
RUN echo hello

Reference