feat: Add env variable support for config (#24)

config/config.go

@@ -2,11 +2,18 @@ package config
 
 import (
 	"fmt"
-	"os"
+	"strings"
 
+	"github.com/mitchellh/mapstructure"
 	"github.com/ojo-network/ethereum-api/pool"
 	"github.com/ojo-network/indexer/server"
-	"gopkg.in/yaml.v3"
+	"github.com/spf13/viper"
+)
+
+const (
+	configFileType    = "yaml"
+	envVariablePrefix = "eth_api"
+	structTagName     = "yaml"
 )
 
 type Exchange struct {
@@ -23,15 +30,33 @@ type Config struct {
 func ParseConfig(filePath string) (*Config, error) {
 	config := Config{}
 
-	yamlFile, err := os.ReadFile(filePath)
-	if err != nil {
-		return nil, err
+	vpr := viper.New()
+	vpr.SetConfigFile(filePath)
+	vpr.SetConfigType(configFileType)
+	vpr.SetEnvPrefix(envVariablePrefix)
+	vpr.AutomaticEnv()
+	vpr.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+
+	if err := vpr.ReadInConfig(); err != nil {
+		return &config, fmt.Errorf("couldn't load config: %s", err)
+	}
+
+	tagConfig := func(decoderConfig *mapstructure.DecoderConfig) {
+		decoderConfig.TagName = structTagName
 	}
 
-	err = yaml.Unmarshal(yamlFile, &config)
-	if err != nil {
-		return nil, err
+	if err := vpr.Unmarshal(&config, tagConfig); err != nil {
+		return &config, fmt.Errorf("couldn't read config: %s", err)
 	}
+
+	// Split NodeUrls from environment variables
+	for i := range config.Exchanges {
+		envVarName := fmt.Sprintf("exchanges.%d.node_urls", i)
+		if v := vpr.GetString(envVarName); v != "" {
+			config.Exchanges[i].NodeUrls = strings.Split(v, ",")
+		}
+	}
+
 	return &config, config.Validate()
 }
 

sample-config.yaml

@@ -2,8 +2,7 @@
 exchanges:
   - name: "uniswap"
     node_urls:
-      - "wss://ethereum-mainnet.core.chainstack.com/ws/5f899c2bcc20c7d53a77f049887752ca"
-      - "wss://ethereum.publicnode.com"
+      - "YOUR NODE URL HERE"
     pools:
       - address: "0x88e6a0c2ddd26feeb64f039a2c41296fcb3f5640"
         base: "WETH"
@@ -55,7 +54,7 @@ exchanges:
         invert_price: false
   - name: "camelot"
     node_urls:
-      - "wss://arbitrum-one-rpc.publicnode.com"
+      - "YOUR NODE URL HERE"
     pools:
       - address: "0x8Bf9C3975172c57E37b3D1c1348e9b5280FB3BaA"
         base: "MILKTIA"
@@ -65,7 +64,7 @@ exchanges:
         invert_price: false
   - name: "balancer"
     node_urls:
-      - "wss://mainnet.infura.io/ws/v3/6849a09aeeb044b592d46bcdce07ccef"
+      - "YOUR NODE URL HERE"
     pools:
       - address: "0x4216d5900a6109bba48418b5e2AB6cc4e61Cf477"
         base: "AMPHRETH"
@@ -117,7 +116,7 @@ exchanges:
         invert_price: false
   - name: "pancake"
     node_urls:
-      - "wss://mainnet.infura.io/ws/v3/6849a09aeeb044b592d46bcdce07ccef"
+      - "YOUR NODE URL HERE"
     pools:
       - address: "0x365EA9E5Cec960390f35b6509548e84073168A8B"
         base: "SWBTC"