WeasyPrint install instructions for Alpine Linux

[elyak123]

Just wanted to recommend adding to documentation instructions to install WeasyPrint in Alpine Linux 3.6. It took me a while but I made it work with this command:
apk --update --upgrade add gcc musl-dev jpeg-dev zlib-dev libffi-dev cairo-dev pango-dev gdk-pixbuf

If someone else have a more efficient aproach (important when working with docker containers for small size images) can comment on this.

[liZe]

Thank you!

[VDShark]

Also spent some time for finding non redundant solution.

As a result of experiments, found next
1) these packages required for running cairo pango gdk-pixbuf
2) these packages required only on the building stage gcc musl-dev libffi-dev jpeg-dev zlib-dev (and could be deleted after that for keeping image as small/clean as possible )

Alpine broke ldconfig...
docker-library/python#111

So unfortunately it looks most simple way now - include gcc and dev versions into build.
This is awful, because size of the image increased 2 times...

packages for run: gcc cairo-dev pango-dev gdk-pixbuf
packages for build: musl-dev jpeg-dev zlib-dev libffi-dev

P.S. Will hope they will fix this, workarounds with LD_LIBRARY_PATH also not looks as working now (waiting PR into python)

[VDShark]

Finally!
With the latest versions of alpine & weasyprint we can keep build pretty small & clean.

Here my current approach:

FROM python:3.7-alpine
ENV PYTHONUNBUFFERED 1

RUN apk --update --upgrade --no-cache add \
    cairo-dev pango-dev gdk-pixbuf

...

ADD /etc/pip/requirements.txt /code/requirements.txt
RUN set -ex \
    && apk add --no-cache --virtual .build-deps \
        musl-dev gcc jpeg-dev zlib-dev libffi-dev \
    && pip install --no-cache-dir -r /code/requirements.txt \
    && apk del .build-deps

...

Packages cairo-dev pango-dev gdk-pixbuf need in runtime, so we kept them.
Other ones need only on building stage - so we clean.

In requirements.txt just weasyprint and my specific dependencies, not related to this issue.

[dploeger]

For somebody who came around this issue because they couldn't install weasyprint on Alpine now, here's the two lines to get it installed:

apk add python3 py3-pip pango gcc musl-dev py3-wheel python3-dev libffi-dev zlib-dev jpeg-dev
pip install weasyprint

[dploeger]

And this is also documented which I somehow overread 🙄

[jo-bitsch]

I recently used the following commands for my docker containers (alpine 3.17):

apk add python3 py3-pip pango
pip install weasyprint
weasyprint -h

which of course uses the precompiled python wheels for musllinux for cffi, Pillow, fonttools, brotli, zopfli, but worked excellent for me to produce a small image, without having to install and uninstall build dependencies.

I tested this on CPython 3.10 musllinux: musl 1.1+ x86-64, but I'm confident, it would also work for aarch64.

[liZe]

I recently used the following commands for my docker containers (alpine 3.17):

It can probably work without the -dev packages if wheels are available for all Python dependencies. But you’ll need for sure Pango, and harfbuzz-subset if you want fast font subsetting.

If someone wants to update the list, please test with a minimal Alpine installation and open a pull request!

[jo-bitsch]

To test that all the libraries load in a minimal alpine install, you can run:

docker run -ti alpine sh -c "apk add py3-pip pango && pip install weasyprint && weasyprint -h"

To properly use it, I have some fonts locally available, alternatively you can add font-dejavu as an additional dependency.

pango depends on harfbuzz which already provides libharfbuzz-subset.so.0, so I'm not sure if I should add it as an explicit dependency.

I'll open a pull-request on the documentation later this week.

Thanks, for the excellent work on weasyprint.

[liZe]

To properly use it, I have some fonts locally available, alternatively you can add font-dejavu as an additional dependency.

We usually don’t include fonts in required packages, and let users install the ones they want or use @font-face fonts.

pango depends on harfbuzz which already provides libharfbuzz-subset.so.0, so I'm not sure if I should add it as an explicit dependency.

I’m not an Alpine user, so I don’t know how its package manager works. It looks like libharfbuzz-subset.so.0 is provided by the harfbuzz-subset package, that’s a sub package of harfbuzz. Are all subpackages automatically installed when a package is installed?

I'll open a pull-request on the documentation later this week.

Thanks, for the excellent work on weasyprint.

Thanks a lot!

[jo-bitsch]

I just remembered, there is a better way in alpine to be explicit about the dependencies, directly referring to the .so files like this:

apk add so:libgobject-2.0.so.0 so:libpango-1.0.so.0 so:libharfbuzz.so.0 so:libharfbuzz-subset.so.0 so:libfontconfig.so.1 so:libpangoft2-1.0.so.0

This form is slightly more verbose but stable against package splits and very explicitly the actual dependency that is referred to in ffi.py

I collected the list from

WeasyPrint/weasyprint/text/ffi.py

Lines 444 to 462 in ca74c8e

	gobject = _dlopen(
	ffi, 'libgobject-2.0-0', 'gobject-2.0-0', 'gobject-2.0',
	'libgobject-2.0.so.0', 'libgobject-2.0.dylib', 'libgobject-2.0-0.dll')
	pango = _dlopen(
	ffi, 'libpango-1.0-0', 'pango-1.0-0', 'pango-1.0', 'libpango-1.0.so.0',
	'libpango-1.0.dylib', 'libpango-1.0-0.dll')
	harfbuzz = _dlopen(
	ffi, 'libharfbuzz-0', 'harfbuzz', 'harfbuzz-0.0',
	'libharfbuzz.so.0', 'libharfbuzz.0.dylib', 'libharfbuzz-0.dll')
	harfbuzz_subset = _dlopen(
	ffi, 'libharfbuzz-subset-0', 'harfbuzz-subset', 'harfbuzz-subset-0.0',
	'libharfbuzz-subset.so.0', 'libharfbuzz-subset.0.dylib', 'libharfbuzz-subset-0.dll',
	allow_fail=True)
	fontconfig = _dlopen(
	ffi, 'libfontconfig-1', 'fontconfig-1', 'fontconfig',
	'libfontconfig.so.1', 'libfontconfig.1.dylib', 'libfontconfig-1.dll')
	pangoft2 = _dlopen(
	ffi, 'libpangoft2-1.0-0', 'pangoft2-1.0-0', 'pangoft2-1.0',
	'libpangoft2-1.0.so.0', 'libpangoft2-1.0.dylib', 'libpangoft2-1.0-0.dll')

Are all subpackages automatically installed when a package is installed?

No, not in general. However, in this specific case harfbuzz provides the file, also.