From c9ef1ccacd151ecab9fd78d9fe6a17f7b60be7cc Mon Sep 17 00:00:00 2001
From: Stefan Strigler <stefan.strigler@emqx.io>
Date: Thu, 1 Jun 2023 20:48:15 +0200
Subject: [PATCH] fix: headers is array not object

---
 apps/emqx_prometheus/src/emqx_prometheus.app.src    | 2 +-
 apps/emqx_prometheus/src/emqx_prometheus_schema.erl | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/apps/emqx_prometheus/src/emqx_prometheus.app.src b/apps/emqx_prometheus/src/emqx_prometheus.app.src
index a0d4dee04..147dcc28f 100644
--- a/apps/emqx_prometheus/src/emqx_prometheus.app.src
+++ b/apps/emqx_prometheus/src/emqx_prometheus.app.src
@@ -2,7 +2,7 @@
 {application, emqx_prometheus, [
     {description, "Prometheus for EMQX"},
     % strict semver, bump manually!
-    {vsn, "5.0.11"},
+    {vsn, "5.0.12"},
     {modules, []},
     {registered, [emqx_prometheus_sup]},
     {applications, [kernel, stdlib, prometheus, emqx, emqx_management]},
diff --git a/apps/emqx_prometheus/src/emqx_prometheus_schema.erl b/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
index f8005f06b..370582304 100644
--- a/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
+++ b/apps/emqx_prometheus/src/emqx_prometheus_schema.erl
@@ -59,7 +59,7 @@ fields("prometheus") ->
             ?HOCON(
                 list({string(), string()}),
                 #{
-                    default => #{},
+                    default => [],
                     required => false,
                     converter => fun ?MODULE:convert_headers/1,
                     desc => ?DESC(headers)
@@ -149,6 +149,8 @@ fields("prometheus") ->
 desc("prometheus") -> ?DESC(prometheus);
 desc(_) -> undefined.
 
+convert_headers(<<>>) ->
+    [];
 convert_headers(Headers) when is_map(Headers) ->
     maps:fold(
         fun(K, V, Acc) ->