Variable names can only contain alphanumeric or underscore characters
FROM alpine
ENV var value
RUN echo $var:test
FROM alpine
ENV var_ value
RUN echo $var_:test
In the two Dockerfiles above, if we put the cursor in the variable within the RUN instruction, our variable highlighting, renaming, and definition lookup features will not work. This is because the system will think the variable's name is var:test or var_:test instead of simply var and var_.
Variable names can only contain alphanumeric or underscore characters
In the two Dockerfiles above, if we put the cursor in the variable within the
RUN
instruction, our variable highlighting, renaming, and definition lookup features will not work. This is because the system will think the variable's name isvar:test
orvar_:test
instead of simplyvar
andvar_
.