buildkit/NoEmptyContinuation¶

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

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¶

• buildkit/NoEmptyContinuation