From 25d8f4f28473cc4a2afa1a87b99441894fce64bf Mon Sep 17 00:00:00 2001
From: Stefan Strigler <stefan@strigler.de>
Date: Wed, 30 Oct 2024 10:17:24 +0100
Subject: [PATCH 1/2] mod_prometheus: use 'declare' rather than 'new' for
 histogram and counter  (#339)

If a node crashes metrics might already be defined in prometheus and thus 'new'
would crash.
---
 mod_prometheus/src/mod_prometheus.erl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mod_prometheus/src/mod_prometheus.erl b/mod_prometheus/src/mod_prometheus.erl
index 2e7f879b..03dab6cf 100644
--- a/mod_prometheus/src/mod_prometheus.erl
+++ b/mod_prometheus/src/mod_prometheus.erl
@@ -352,7 +352,7 @@ handle_histogram(Name, HName, HistogramOpts, Host, Action, State) ->
   InitArg = State#{name => HName, labels => LabelNames},
   case Action of
     subscribe ->
-      prometheus_histogram:new(
+      prometheus_histogram:declare(
         [
           {name, HName},
           {buckets, maps:get(buckets, HistogramOpts, [1, 10, 100, 500, 750, 1000, 3000, 5000])},
@@ -377,7 +377,7 @@ handle_counter(Name, HName, CounterOpts, Host, Action, State) ->
   InitArg = State#{name => HName, labels => LabelNames},
   case Action of
     subscribe ->
-      prometheus_counter:new(
+      prometheus_counter:declare(
         [{name, HName}, {help, maps:get(help, CounterOpts, "No help")}, {labels, LabelNames}]
       ),
       ?INFO_MSG("Created new Prometheus counter for ~p with labels ~p", [HName, LabelNames]),
@@ -441,4 +441,4 @@ find_stanza_type([Arg | Args]) when is_tuple(Arg) ->
 find_stanza_type([_ | Args]) ->
   find_stanza_type(Args);
 find_stanza_type([]) ->
-  unknown.
\ No newline at end of file
+  unknown.

From 769dbf0f9459c90923c1115cef3a57527516e8b3 Mon Sep 17 00:00:00 2001
From: Stefan Strigler <stefan@strigler.de>
Date: Mon, 4 Nov 2024 08:18:33 +0000
Subject: [PATCH 2/2] don't loose data of docker containers

---
 mod_prometheus/example/docker-compose.yml | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/mod_prometheus/example/docker-compose.yml b/mod_prometheus/example/docker-compose.yml
index afaf5ccc..47d5c728 100644
--- a/mod_prometheus/example/docker-compose.yml
+++ b/mod_prometheus/example/docker-compose.yml
@@ -3,17 +3,25 @@ version: '3.7'
 services:
 
   prometheus:
-    network_mode: "host"
     image: docker.io/prom/prometheus
     container_name: prometheus
     ports:
       - "9090:9090"
     volumes:
+      - prometheus-data:/prometheus
       - ./prometheus.yml:/etc/prometheus/prometheus.yml
+    restart: always
 
   grafana:
-    network_mode: "host"
     image: docker.io/grafana/grafana-enterprise
     container_name: grafana
     ports:
       - "3000:3000"
+    volumes:
+      - grafana-data:/var/lib/grafana
+      - ./grafana_defaults.ini:/usr/share/grafana/conf/defaults.ini
+    restart: always
+
+volumes:
+  prometheus-data:
+  grafana-data: