More prometheus metrics

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "lib/accept"]
 	path = lib/accept
 	url = https://github.com/deadtrickster/accept.git
+[submodule "lib/prometheus_process_collector"]
+	path = lib/prometheus_process_collector
+	url = https://github.com/deadtrickster/prometheus_process_collector.git

Makefile

@@ -3,7 +3,11 @@
 DIALYZER = dialyzer
 PLT_APPS = erts kernel stdlib sasl inets ssl public_key crypto compiler  mnesia sasl eunit asn1 compiler runtime_tools syntax_tools xmerl edoc tools os_mon
 
-ERL_OPTS= -pa ebin/ -pa lib/prometheus/_build/default/lib/prometheus/ebin -pa lib/accept/_build/default/lib/accept/ebin -s prometheus
+ERL_OPTS= -pa ebin/ \
+	-pa lib/prometheus/_build/default/lib/prometheus/ebin \
+	-pa lib/accept/_build/default/lib/accept/ebin \
+	-pa lib/prometheus_process_collector/_build/default/lib/prometheus_process_collector/ebin \
+	-s prometheus
 
 test_all: test test_apps
 
@@ -37,6 +41,7 @@ all: ebin logs blocks
 	git submodule update
 	(cd lib/prometheus && ./rebar3 compile)
 	(cd lib/accept && ./rebar3 compile)
+	(cd lib/prometheus_process_collector && ./rebar3 compile && cp _build/default/lib/prometheus_process_collector/priv/*.so ../../priv)
 	erlc +export_all -o ebin/ src/ar.erl
 	erl $(ERL_OPTS) -noshell -s ar rebuild -s init stop
 

arweave-server

@@ -13,4 +13,5 @@ fi
 exec erl $SHELL_OPTS -pa ebin/ \
 	-pa lib/prometheus/_build/default/lib/prometheus/ebin \
 	-pa lib/accept/_build/default/lib/accept/ebin \
+	-pa lib/prometheus_process_collector/_build/default/lib/prometheus_process_collector/ebin \
 	-s ar rebuild -s prometheus  -run ar main "$@"

src/ar.erl

@@ -146,6 +146,10 @@ start(
 	}) ->
 	% Optionally clear the block cache
 	if Clean -> ar_storage:clear(); true -> do_nothing end,
+	%register prometheus stats collector,
+	%prometheus collector app is started at cmdline
+	application:ensure_started(prometheus),
+	prometheus_registry:register_collector(prometheus_process_collector),
 	% Start apps which we depend on.
 	inets:start(),
 	ar_meta_db:start(),