Add new changelog process

- Adds a changelog update section to the docs
- creates the base CHANGES.rst file
- creates the CHANGES directory for news updates and indicates to git to
  store the dir even if empty with a .gitignore.
- adds a release note for this change
- adds a docs section that loads the CHANGES.rst file on the website

https://pulp.plan.io/issues/5501
re #5501

CHANGES.rst

@@ -0,0 +1,15 @@
+=========
+Changelog
+=========
+
+..
+    You should *NOT* be adding new change log entries to this file, this
+    file is managed by towncrier. You *may* edit previous change logs to
+    fix problems like typo corrections or such.
+    To add a new change log entry, please see
+    https://docs.pulpproject.org/en/3.0/nightly/contributing/git.html#changelog-update
+
+    WARNING: Don't drop the next directive!
+
+.. towncrier release notes start
+

CHANGES/.TEMPLATE.rst

@@ -0,0 +1,37 @@
+{# TOWNCRIER TEMPLATE #}
+{% for section, _ in sections.items() %}
+{% set underline = underlines[0] %}{% if section %}{{section}}
+{{ underline * section|length }}{% set underline = underlines[1] %}
+
+{% endif %}
+
+{% if sections[section] %}
+{% for category, val in definitions.items() if category in sections[section]%}
+{{ definitions[category]['name'] }}
+{{ underline * definitions[category]['name']|length }}
+
+{% if definitions[category]['showcontent'] %}
+{% for text, values in sections[section][category].items() %}
+- {{ text }}
+  {{ values|join(',\n  ') }}
+{% endfor %}
+
+{% else %}
+- {{ sections[section][category]['']|join(', ') }}
+
+{% endif %}
+{% if sections[section][category]|length == 0 %}
+No significant changes.
+
+{% else %}
+{% endif %}
+
+{% endfor %}
+{% else %}
+No significant changes.
+
+
+{% endif %}
+{% endfor %}
+----
+

CHANGES/.gitignore

@@ -0,0 +1,2 @@
+!.gitignore
+

CHANGES/5501.doc

@@ -0,0 +1 @@
+Switch to using `towncrier <https://github.com/hawkowl/towncrier>`_ for better release notes.

doc_requirements.txt

@@ -0,0 +1,15 @@
+coreapi
+django
+djangorestframework
+djangorestframework-queryfields
+django-filter
+drf-nested-routers
+drf-yasg
+dynaconf
+plantuml
+pyyaml
+rq
+sphinx
+sphinx-rtd-theme
+sphinxcontrib-openapi
+towncrier

docs/Makefile

@@ -0,0 +1,165 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS           = -W  # turn warnings into errors
+SPHINXBUILD          = sphinx-build
+PAPER                =
+BUILDDIR             = _build
+DIAGRAM_BUILD_DIR    = _diagrams
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest gettext diagrams
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  diagrams   to make diagram images"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+
+clean:
+	rm -rf $(BUILDDIR)/*
+	rm -rf $(DIAGRAM_BUILD_DIR)/*
+
+diagrams:
+	mkdir -p $(DIAGRAM_BUILD_DIR)
+	python3 -m plantuml diagrams_src/*.dot
+	# cp + rm = mv  workaround https://pulp.plan.io/issues/4791#note-3
+	cp diagrams_src/*.png $(DIAGRAM_BUILD_DIR)/
+	rm diagrams_src/*.png
+
+html:
+	mkdir -p $(BUILDDIR)/html
+	curl -o _build/html/api.json "http://localhost:24817/pulp/api/v3/docs/?format=openapi"
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/PulpDocs.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/PulpDocs.qhc"
+
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/PulpDocs"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/PulpDocs"
+	@echo "# devhelp"
+
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."

docs/_templates/restapi.html

@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Pulp-2to3-Migration REST API documentation</title>
+    <!-- needed for adaptive design -->
+    <meta charset="utf-8"/>
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <link href="https://fonts.googleapis.com/css?family=Montserrat:300,400,700|Roboto:300,400,700" rel="stylesheet">
+
+    <!--
+    ReDoc doesn't change outer page styles
+    -->
+    <style>
+      body {
+        margin: 0;
+        padding: 0;
+      }
+    </style>
+  </head>
+  <body>
+    <redoc spec-url='api.json'></redoc>
+    <script src="https://cdn.jsdelivr.net/npm/redoc@next/bundles/redoc.standalone.js"> </script>
+  </body>
+</html>

docs/changes.rst

@@ -0,0 +1,5 @@
+.. _pulp-2to3-migration-changes:
+
+.. include:: ../CHANGES.rst
+
+.. include:: ../HISTORY.rst