Re: [belenios-discuss] Statically linking Belenios

[Alban Bruder <alban.bruder AT uni-weimar.de>]

Thank you for the quick response,

this sounds great. Thanks to the approach taken in the nspawn example I 
managed to build an Alpine Linux based Docker image with less than 100MB. (:

In the end we don't need a fully static  build. The smaller footprint is 
sufficient.

Thanks!

On 18.08.21 14:48, Stéphane Glondu wrote:
> Dear Alban,
>
> Le 18/08/2021 à 14:07, Alban Bruder a écrit :
> > for a slimmed down installation, I am trying to statically link
> > Belenios. My incentive is that the whole OPAM installation is quite big
> > (around 3 GB) and I wonder if this could be less. E.G for a distribution
> > where only the binaries and the Belenios source code would be required.
> This is exactly what is done in doc/nspawn:
>
>    https://gitlab.inria.fr/belenios/belenios/-/tree/master/doc/nspawn
>
> With Belenios 1.15, one can get a ~200 MB image; with 1.16, it is ~400
> MB and with master, it is ~125 MB.
>
> > My understanding of OCAML/OPAM is that this might be possible by
> > including "(flags (-ccopt -static))" in the dune files. Did one of you
> > already try this or is it a bad idea?
> This might work for belenios-tool, but not for the web server (at least
> in <= 1.16). Indeed, ocsigenserver does dynamic lookups and loading of
> numerous OCaml libraries which cannot be avoided by merely stuffing
> -static into the linking command line.
>
> However, in master, I've implemented so-called "static linking" (in the
> Ocsigen/Eliom sense; beware, this is not exactly what you mean) of the
> web server. It consists in creating a new executable, "belenios-server"
> that embeds ocsigenserver, eliom, belenios and all OCaml libraries. It
> still uses shared libraries (such as libc and libssl), though. I guess
> it could be workable to turn this "belenios-server" executable into a
> true static binary but I didn't try. The reduced size of the nspawn
> image in master is due to this new strategy.
>
> If your goal is to reduce the footprint of Belenios and its dependencies
> on a production server, I would recommend to use nspawn as instructed above.
>
>
> Cheers,

--
Alban Bruder

Studiengang Medieninformatik, B.Sc.

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