Docker improvements (#3042)

* Simplified dockerfile

- Changed from alpine to python:slim
- Removed some database libs (because we *connect* to a db, not host it)

* - Add gettext as required package
- Only create inventree user as part of production build (leave admin access for dev build)

* Tweaks for tasks.py

* Fix user permissions (drop to inventree user)

* Drop to the 'inventree' user level as part of init.sh

- As we have mounted volumes at 'run time' we need to ensure that the inventree user has correct permissions!
- Ref: https://stackoverflow.com/questions/39397548/how-to-give-non-root-user-in-docker-container-access-to-a-volume-mounted-on-the

* Adjust user setup

- Only drop to non-root user as part of "production" build
- Mounted external volumes make it tricky when in the dev build
- Might want to revisit this later on

* More dockerfile changes

- reduce required system packages
-

* Add new docker github workflow

* Print some more debug

* GITHUB_BASE_REF

* Add gnupg to base requirements

* Improve debug output during testing

* Refactoring updates for label printing API

- Update weasyprint version to 55.0
- Generate labels as pdf files
- Provide filename to label printing plugin
- Additional unit testing
- Improve extraction of some hidden debug data during TESTING
- Fix a spelling mistake (notifaction -> notification)

* Working on github action

* More testing

* Add requirement for pdf2image

* Fix label printing plugin and update unit testing

* Add required packages for CI

* Move docker files to the top level directory

- This allows us to build the production image directly from soure
- Don't need to re-download the source code from github
- Note: The docker install guide will need to be updated!

* Fix for docker ci file

* Print GIT SHA

* Bake git information into the production image

* Add some exta docstrings to dockerfile

* Simplify version check script

* Extract git commit info

* Extract docker tag from check_version.py

* Newline

* More work on the docker workflow

* Dockerfile fixes

- Directory / path issues

* Dockerfile fixes

- Directory / path issues

* Ignore certain steps on a pull request

* Add poppler-utils to CI

* Consolidate version check into existing CI file

* Don't run docker workflow on pull request

* Pass docker image tag through to the build

Also check .j2k files

* Add supervisord.conf example file back in

* Remove --no-cache-dir option from pip install

InvenTree/label/api.py

@@ -1,12 +1,9 @@
-from io import BytesIO
-
 from django.conf import settings
 from django.core.exceptions import FieldError, ValidationError
 from django.http import HttpResponse, JsonResponse
 from django.urls import include, re_path
 
 from django_filters.rest_framework import DjangoFilterBackend
-from PIL import Image
 from rest_framework import filters, generics
 from rest_framework.exceptions import NotFound
 
@@ -137,25 +134,21 @@ class LabelPrintMixin:
             # Label instance
             label_instance = self.get_object()
 
-            for output in outputs:
+            for idx, output in enumerate(outputs):
                 """
                 For each output, we generate a temporary image file,
                 which will then get sent to the printer
                 """
 
-                # Generate a png image at 300dpi
-                (img_data, w, h) = output.get_document().write_png(resolution=300)
-
-                # Construct a BytesIO object, which can be read by pillow
-                img_bytes = BytesIO(img_data)
-
-                image = Image.open(img_bytes)
+                # Generate PDF data for the label
+                pdf = output.get_document().write_pdf()
 
                 # Offload a background task to print the provided label
                 offload_task(
                     plugin_label.print_label,
                     plugin.plugin_slug(),
-                    image,
+                    pdf,
+                    filename=label_names[idx],
                     label_instance=label_instance,
                     user=request.user,
                 )