some alpine related deps questions

[iham]

i am fiddling with plone docker for some days now and stumbled upon alpine the other day...

and i like it - obviously...

i did my own docker using buildout instead of unified installer ...

now i need to ask - as i am not familiar with alpine and so on...

the build-deps are
gcc
libc-dev
zlib-dev
libjpeg-turbo-dev
libpng-dev
libxml2-dev
libxslt-dev
pcre-dev

which are only used to get the enviroment and buildout done.

then those get removed and some other packages get installed:
bash
libxml2
libxslt
libjpeg-turbo

1.) why is there no libpng anymore? is that include anywhere else after pil was compiled?
2.) do i need bash? - found out docker-entrypoint.sh does make some trouble about operands not found ... any help about that?

3.) where to add vw and poppler-utils? to the run-deps i guess?
4.) why are the none *-dev packages used afterwards?

thanks for your help :)