Inspectopedia Help

Invalid spaces in ''key=value'' pair

Reports incorrect spacing for key-value pairs in ARG, ENV, and LABEL commands.

While it is not explicitly specified in the Dockerfile specification, some combinations of spacing for key-value pairs are not allowed. Docker build will fail after reaching the problem instruction.


  • The ARG command does not allow any spaces around '='

  • ENV and LABEL do not allow spaces after '='

# all the commands below will fail ARG answer = 42 ARG version= "1.0.0" LABEL ""= ENV JAVA_HOME= "/docker-java-home"

After the quick-fix is applied:

ARG answer=2 ARG version="1.0.0" LABEL "" ENV JAVA_HOME="/docker-java-home"
Last modified: 20 February 2024