Using indented HEREDOC with Rex tasks #1533

HEREDOCs should work in general. Rex code is just Perl code, there's no distinction.

The Compile time errors message suggests that Rex receives invalid Perl code somehow. When loading the Rexfile upon rex execution, it is treated as a perl module named __Rexfile__. This helps avoiding to execute invalid code, by detecting them early (and offloads the whole check to standard perl).

The problem here is that the ending delimiter LOADER is indented with 8 spaces, while the previous lines are indented with single tabs. I could reproduce the initial error, but when I made the HEREDOC indentation correct, it worked for me as expected.

That being said, in general I would not recommend using the append_if_no_such_line() command to manage multiple lines like that. Its purpose is to operate on single lines, so it's not an optimal choice to manage multiple lines. As the docs state:

If no regexp is supplied, the line is appended unless there is already an identical line in $file.

Checking the presence of a multiline input while operating on a line-by-line basis would certainly not work as expected. It would fail to detect whether the content is already there or not, and just append it anyway each time this task is executed.

To append two lines, call append_if_no_such_line twice:

append_if_no_such_line $file, q(kernel="kernel");
append_if_no_such_line $file, q(bootfile="/boot/kernel/kernel");

Alternatively, for best experience, I would recommend using file() (with content => template(), perhaps) to manage file content with a single operation.