FromAsCasing

Output

'as' and 'FROM' keywords' casing do not match

Description

While Dockerfile keywords can be either uppercase or lowercase, mixing case styles is not recommended for readability. This rule reports violations where mixed case style occurs for a FROM instruction with an AS keyword declaring a stage name.

Examples

❌ Bad: FROM is uppercase, AS is lowercase.

FROM debian:latest as builder

βœ… Good: FROM and AS are both uppercase

FROM debian:latest AS deb-builder

βœ… Good: FROM and AS are both lowercase.

from debian:latest as deb-builder