buildkit/NoEmptyContinuation

Empty continuation lines are deprecated and will cause errors in future Dockerfile syntax versions.

Property	Value
Severity	Error
Category	Correctness
Default	Enabled
Auto-fix	Yes (`--fix`)

Description

Support for empty continuation (\) lines has been deprecated and will generate errors in future versions of the Dockerfile syntax. Empty continuation lines are empty lines following a newline escape.

Examples

Bad:

FROM alpine
EXPOSE \

80

Good:

FROM alpine
EXPOSE \
# Port
80

Bad:

FROM alpine
RUN apk add \

    gnupg \

    curl

Good (empty lines removed):

FROM alpine
RUN apk add \
    gnupg \
    curl

Auto-fix

The fix removes empty continuation lines from multi-line commands.

Reference