Re: [RFC PATCH net-next mlxsw 03/14] selftests: forwarding: README: Document customization

[Jakub Kicinski <kuba@kernel.org>]

On Mon, 25 Mar 2024 18:29:10 +0100 Petr Machata wrote:
> +The forwarding selftests framework uses a number of variables that
> +influence its behavior and tools it invokes, and how it invokes them, in
> +various ways. A number of these variables can be overridden. The way these
> +overridable variables are specified is typically one of the following two
> +syntaxes:
> +
> +	: "${VARIABLE:=default_value}"
> +	VARIABLE=${VARIABLE:=default_value}
> +
> +Any of these variables can be overridden. Notably net/forwarding/lib.sh and
> +net/lib.sh contain a number of overridable variables.
> +
> +One way of overriding these variables is through the environment:
> +
> +	PAUSE_ON_FAIL=yes ./some_test.sh

I like this conversion a lot. Makes me want to propose that we make this
a standard feature of kselftest. If "env" file exists in the test
directory kselftest would load its contents before running every test.

That's more of a broader question to anyone reading on linux-kselftest@
if there's no interest more than happy to merge as is :)

> +The variable NETIFS is special. Since it is an array variable, there is no
> +way to pass it through the environment. Its value can instead be given as
> +consecutive arguments to the selftest:
> +
> +	./some_test.sh swp{1..8}

Did you consider allowing them to be defined as NETIF_0, NETIF_1 etc.?
We can have lib.sh convert that into an array with a ugly-but-short
loop, it's a bit tempting to get rid of the exception.