Remove OpenSSL from alpine-slim images

[ferferga]

Is your feature request related to a problem? Please describe

I use this image for shipping a frontend application that just needs file serving. SSL handling is done with another reverse proxy, so the extra weight (4 MB+ uncompressed, which is quite noticeable) by OpenSSL is wasteful and could be improved

Describe the solution you'd like

As stated in the docs, the alpine slim images are intended for the most basic cases (like mine). For those tags, nginx should be built without SSL support, leaving the normal images for users who desire that.

Describe alternatives you've considered

• Remove openssl using apk
• Remove the linked libraries manually in a build step, but nginx has a hard requirement on them.
• Patching the binary with patchelf, but it doesn't start even when forcing ssl off in the main http block.

[oxpa]

@ferferga have you considered building your own image? Given that the Dockefile and all sources are available - it's not a big deal.
SSL is an important feature which is definitely needed even in a slim image.

[thresheek]

Agreed, SSL support is something we will not remove from the images.