docs: Convert manpages from DocBook to mdoc(7)

Writing those manpages directly in the target markup language allows to
use its full expressiveness, unlike the generated output from DocBook.

To create their HTML versions, we use mandoc(1), plus a small awk script
to adapt the generated HTML to our needs. I tried groff(1) and
man2html(1) but the former transforms nearly everything to simple <p>
and the later tries to reproduce the rendering of a manpage in a
terminal.

Manpages in section 1 are moved to section 8 because they are commands
to manage a system service, not general purpose commands.

This commits requires a change in the website to integrate the new
generated HTML manpages.

[#143563295]

Author: dumbbell

.gitignore

@@ -19,22 +19,8 @@
 /escript
 rabbit.d
 
-# Generated sources files.
-src/rabbit_ctl_usage.erl
-src/rabbit_plugins_usage.erl
-
 # Generated documentation.
-docs/rabbitmq-echopid.man.xml
-docs/rabbitmq-env.conf.5
-docs/rabbitmq-env.conf.5.man.xml
-docs/rabbitmq-plugins.1
-docs/rabbitmq-plugins.1.man.xml
-docs/rabbitmq-server.1
-docs/rabbitmq-server.1.man.xml
-docs/rabbitmq-service.man.xml
-docs/rabbitmqctl.1
-docs/rabbitmqctl.1.man.xml
-docs/*.tmp
+docs/*.html
 
 # Dialyzer
 *.plt

Makefile

@@ -133,15 +133,8 @@ $(subst __,_,$(patsubst $(DOCS_DIR)/rabbitmq%.1.xml, src/rabbit_%_usage.erl, $(s
 endef
 
 DOCS_DIR     = docs
-MANPAGES     = $(patsubst %.xml, %, $(wildcard $(DOCS_DIR)/*.[0-9].xml))
-WEB_MANPAGES = $(patsubst %.xml, %.man.xml, $(wildcard $(DOCS_DIR)/*.[0-9].xml) $(DOCS_DIR)/rabbitmq-service.xml $(DOCS_DIR)/rabbitmq-echopid.xml)
-USAGES_XML   = $(DOCS_DIR)/rabbitmqctl.1.xml $(DOCS_DIR)/rabbitmq-plugins.1.xml
-USAGES_ERL   = $(foreach XML, $(USAGES_XML), $(call usage_xml_to_erl, $(XML)))
-
-EXTRA_SOURCES += $(USAGES_ERL)
-
-.DEFAULT_GOAL = all
-$(PROJECT).d:: $(EXTRA_SOURCES)
+MANPAGES     = $(wildcard $(DOCS_DIR)/*.[0-9])
+WEB_MANPAGES = $(patsubst %,%.html,$(MANPAGES))
 
 DEP_PLUGINS = rabbit_common/mk/rabbitmq-build.mk \
 	      rabbit_common/mk/rabbitmq-dist.mk \
@@ -205,10 +198,7 @@ copy-escripts:
 		PREFIX="$(abspath $(CLI_ESCRIPTS_DIR))" \
 		DESTDIR=
 
-clean:: clean-extra-sources clean-escripts
-
-clean-extra-sources:
-	$(gen_verbose) rm -f $(EXTRA_SOURCES)
+clean:: clean-escripts
 
 clean-escripts:
 	$(gen_verbose) rm -rf "$(CLI_ESCRIPTS_DIR)"
@@ -217,45 +207,6 @@ clean-escripts:
 # Documentation.
 # --------------------------------------------------------------------
 
-# xmlto can not read from standard input, so we mess with a tmp file.
-%: %.xml $(DOCS_DIR)/examples-to-end.xsl
-	$(gen_verbose) xmlto --version | \
-	    grep -E '^xmlto version 0\.0\.([0-9]|1[1-8])$$' >/dev/null || \
-	    opt='--stringparam man.indent.verbatims=0' ; \
-	xsltproc --novalid $(DOCS_DIR)/examples-to-end.xsl $< > $<.tmp && \
-	xmlto -vv -o $(DOCS_DIR) $$opt man $< 2>&1 | (grep -v '^Note: Writing' || :) && \
-	awk -F"'u " '/^\.HP / { print $$1; print $$2; next; } { print; }' "$@" > "$@.tmp" && \
-	mv "$@.tmp" "$@" && \
-	test -f $@ && \
-	rm $<.tmp
-
-# Use tmp files rather than a pipeline so that we get meaningful errors
-# Do not fold the cp into previous line, it's there to stop the file being
-# generated but empty if we fail
-define usage_dep
-$(call usage_xml_to_erl, $(1)):: $(1) $(DOCS_DIR)/usage.xsl
-	$$(gen_verbose) xsltproc --novalid --stringparam modulename "`basename $$@ .erl`" \
-	    $(DOCS_DIR)/usage.xsl $$< > $$@.tmp && \
-	sed -e 's/"/\\"/g' -e 's/%QUOTE%/"/g' $$@.tmp > $$@.tmp2 && \
-	fold -s $$@.tmp2 > $$@.tmp3 && \
-	mv $$@.tmp3 $$@ && \
-	rm $$@.tmp $$@.tmp2
-endef
-
-$(foreach XML,$(USAGES_XML),$(eval $(call usage_dep, $(XML))))
-
-# We rename the file before xmlto sees it since xmlto will use the name of
-# the file to make internal links.
-%.man.xml: %.xml $(DOCS_DIR)/html-to-website-xml.xsl
-	$(gen_verbose) cp $< `basename $< .xml`.xml && \
-	    xmlto xhtml-nochunks `basename $< .xml`.xml ; \
-	rm `basename $< .xml`.xml && \
-	cat `basename $< .xml`.html | \
-	    xsltproc --novalid $(DOCS_DIR)/remove-namespaces.xsl - | \
-	      xsltproc --novalid --stringparam original `basename $<` $(DOCS_DIR)/html-to-website-xml.xsl - | \
-	      xmllint --format - > $@ && \
-	rm `basename $< .xml`.html
-
 .PHONY: manpages web-manpages distclean-manpages
 
 docs:: manpages web-manpages
@@ -266,9 +217,32 @@ manpages: $(MANPAGES)
 web-manpages: $(WEB_MANPAGES)
 	@:
 
+# We use mandoc(1) to convert manpages to HTML plus an awk script which
+# does:
+#     1. remove tables at the top and the bottom (they recall the
+#        manpage name, section and date)
+#     2. "downgrade" headers by one level (eg. h1 -> h2)
+#     3. annotate .Dl lines with more CSS classes
+%.html: %
+	$(gen_verbose) mandoc -T html -O 'fragment,man=%N.%S.html' "$<" | \
+	  awk '\
+	  /^<table class="head">$$/ { remove_table=1; next; } \
+	  /^<table class="foot">$$/ { remove_table=1; next; } \
+	  /^<\/table>$$/ { if (remove_table) { remove_table=0; next; } } \
+	  { if (!remove_table) { \
+	    line=$$0; \
+	    gsub(/<h2/, "<h3", line); \
+	    gsub(/<\/h2>/, "</h3>", line); \
+	    gsub(/<h1/, "<h2", line); \
+	    gsub(/<\/h1>/, "</h2>", line); \
+	    gsub(/class="D1"/, "class=\"D1 sourcecode bash hljs\"", line); \
+	    print line; \
+	  } } \
+	  ' > "$@"
+
 distclean:: distclean-manpages
 
 distclean-manpages::
-	$(gen_verbose) rm -f $(MANPAGES) $(WEB_MANPAGES)
+	$(gen_verbose) rm -f $(WEB_MANPAGES)
 
 app-build: copy-escripts