FileConsistentCommandCasing

Table of contents

Output

Example warning:

Command 'foo' should match the case of the command majority (uppercase)

Description

Instructions within a Dockerfile should have consistent casing through out the entire files. Instructions are not case-sensitive, but the convention is to use uppercase for instruction keywords to make it easier to distinguish keywords from arguments.

Whether you prefer instructions to be uppercase or lowercase, you should make sure you use consistent casing to help improve readability of the Dockerfile.

Examples

❌ Bad: mixed uppercase and lowercase.

FROM alpine:latest AS builder
run apk --no-cache add build-base

FROM builder AS build1
copy source1.cpp source.cpp

✅ Good: all uppercase.

FROM alpine:latest AS builder
RUN apk --no-cache add build-base

FROM builder AS build1
COPY source1.cpp source.cpp

✅ Good: all lowercase.

from alpine:latest as builder
run apk --no-cache add build-base

from builder as build1
copy source1.cpp source.cpp