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Disallows multiple consecutive spaces within Dockerfile instructions.
PropertyValue
SeverityStyle
CategoryStyle
DefaultEnabled
Auto-fixYes (safe)

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Description

Multiple consecutive spaces within Dockerfile instructions are usually accidental and make the code harder to read. This rule flags any run of 2 or more consecutive space characters within instruction lines. The following are excluded:
  • Leading indentation: whitespace before the instruction keyword
  • Heredoc body lines: content between heredoc markers (semantically significant)
  • Comment lines: lines starting with #

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Examples

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Bad

FROM  alpine:3.20
RUN  apk add  --no-cache  curl
COPY  . /app

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Good

FROM alpine:3.20
RUN apk add --no-cache curl
COPY . /app

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Auto-fix

This rule provides a safe auto-fix that replaces each run of multiple spaces with a single space: 
tally lint --fix Dockerfile
Each contiguous run of extra spaces is replaced independently, so a line with multiple occurrences receives one edit per run.

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Configuration

No custom configuration options. The rule is enabled by default with severity “style”. 
# Disable the rule
[rules.tally.no-multi-spaces]
severity = "off"