Re: [PATCH RFC] tests: add feature probing

[Florian Westphal <fw@strlen.de>]

Thomas Haller <thaller@redhat.com> wrote:
> On Mon, 2023-09-04 at 10:53 +0200, Florian Westphal wrote:
> > Thomas Haller <thaller@redhat.com> wrote:
> > > 
> > > 
> > > But why this "nft -f" specific detection? Why not just executable
> > > scripts?
> > 
> > Because I want it to be simple,
> 
> It does not seem "simple[r]" to me. The approach requires extra
> infrastructure in run-test.sh, while being less flexible.

I can add bla.nft and use nft --check -f bla.nft.

Or, I can add bla.sh, which does

exec $NFT -f - <<EOF
table ...
EOF

I see zero reason why we can't add scripts later on if there
are cases where flat-files don't work.

At this point, its just more boilerplate to add a script wrapper
around the .nft file.

> > I could do that, but I don't see the need for arbitrary scripts so
> > far.
> 
> When building without JSON support, various tests fail, but should be
> skipped.
> 
> Could we detect JSON support via .nft files? Would we drop then a JSON
> .nft file and change the check call to `nft --check -j`?).

No, but the test that should be skipped can do

$NFT -j list ruleset || exit 77

as first line of the script, no need to load any files, nft will fail
with error in case its not built with json support.

> Or maybe detection of JSON support needs to be a shell script (doing
> `ldd "$NFT_REAL" | greq libjansson`)? In that case, we would have
> features-as-shell-scripts very soon.

Sure, I see no reason why to not have both.  The flat files have the
'*nft' suffix for a reason...

I'll no longer work on this for the remainder of the month due to
time constraints.