From 3b1de03a22d64f684c690bd28eae3b2a7052b70b Mon Sep 17 00:00:00 2001
From: doxsch <28098153+doxsch@users.noreply.github.com>
Date: Tue, 13 Feb 2024 21:14:46 +0100
Subject: [PATCH] fix: set environment variables config values correctly for
 camelCase config keys

---
 config.go | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/config.go b/config.go
index ac7e728..3c65e0f 100644
--- a/config.go
+++ b/config.go
@@ -11,6 +11,7 @@ import (
 	"github.com/cloudhut/kminion/v2/prometheus"
 	"github.com/knadh/koanf"
 	"github.com/knadh/koanf/parsers/yaml"
+	"github.com/knadh/koanf/providers/confmap"
 	"github.com/knadh/koanf/providers/env"
 	"github.com/knadh/koanf/providers/file"
 	"github.com/mitchellh/mapstructure"
@@ -102,6 +103,23 @@ func newConfig(logger *zap.Logger) (Config, error) {
 		return Config{}, err
 	}
 
+	// Lowercase the keys that are stored internally within Koanf and reload them. This is a workaround because
+	// internally keys are stored case sensitive. This causes the problem that environment variables can't match
+	// the exact key and therefore will not be unmarshalled as expected anymore. Example:
+	// YAML path: minion.endToEnd.enabled
+	// ENV path: MINION_ENDTOEND_ENABLED => minion.endtoend.enabled
+	// Internal key: minion.endToEnd.enabled
+	// See issue: https://github.com/redpanda-data/kminion/issues/179
+	keys := make(map[string]interface{}, len(k.Keys()))
+	for _, key := range k.Keys() {
+		keys[strings.ToLower(key)] = k.Get(key)
+	}
+	k.Delete("")
+	err = k.Load(confmap.Provider(keys, "."), nil)
+	if err != nil {
+		return Config{}, fmt.Errorf("failed to unmarshal confmap variables into config struct: %w", err)
+	}
+
 	err = k.Unmarshal("", &cfg)
 	if err != nil {
 		return Config{}, err