added config file slice support (#5122)

* added config file slice support

* ReadMe update

README.md

@@ -175,6 +175,48 @@ C:\ProgramData\chocolatey\lib\mingw\tools\install\mingw64\bin
   **Please also note the default WSL2 environment has its own IP address which does not match the one of the network
   interface of Windows host: take this into account when configuring NAT for port 30303 on your router.**
 
+### Using TOML or YAML Config Files
+
+You can set Erigon flags through a YAML or TOML configuration file with the flag `--config`. The flags set in the configuration
+file can be overwritten by writing the flags directly on Erigon command line
+
+## Example
+
+`./build/bin/erigon --config ./config.yaml --chain=goerli
+
+Assuming we have `chain : "mainnet" in our configuration file, by adding `--chain=goerli` allows the overwrite of the flag inside
+of the yaml configuration file and sets the chain to goerli
+
+## TOML 
+
+Example of setting up TOML config file
+
+```
+`datadir = 'your datadir'
+port = "1111"
+chain = "mainnet"
+http = "true"
+"private.api.addr"="localhost:9090"
+
+"http.api" = ["eth","debug","net"]
+```
+
+## YAML 
+
+Example of setting up a YAML config file
+
+```
+datadir : 'your datadir'
+port : "1111"
+chain : "mainnet"
+http : "true"
+private.api.addr : "localhost:9090"
+
+http.api : ["eth","debug","net"]
+```
+
+
+
 ### Beacon Chain (Consensus Layer)
 
 Erigon can be used as an Execution Layer (EL) for Consensus Layer clients (CL). Default configuration is OK. CL

cmd/erigon/main.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"reflect"
+	"strings"
 
 	"github.com/ledgerwatch/erigon-lib/common/dbg"
 	"github.com/ledgerwatch/erigon/cmd/utils"
@@ -68,7 +70,7 @@ func runErigon(cliCtx *cli.Context) {
 func setFlagsFromConfigFile(ctx *cli.Context, filePath string) error {
 	fileExtension := filepath.Ext(filePath)
 
-	fileConfig := make(map[string]string)
+	fileConfig := make(map[string]interface{})
 
 	if fileExtension == ".yaml" {
 		yamlFile, err := os.ReadFile(filePath)
@@ -91,13 +93,25 @@ func setFlagsFromConfigFile(ctx *cli.Context, filePath string) error {
 	} else {
 		return errors.New("config files only accepted are .yaml and .toml")
 	}
-
 	// sets global flags to value in yaml/toml file
 	for key, value := range fileConfig {
 		if !ctx.GlobalIsSet(key) {
-			err := ctx.GlobalSet(key, value)
-			if err != nil {
-				return err
+			if reflect.ValueOf(value).Kind() == reflect.Slice {
+				sliceInterface := value.([]interface{})
+				s := make([]string, len(sliceInterface))
+				for i, v := range sliceInterface {
+					s[i] = v.(string)
+				}
+				fmt.Println(s)
+				err := ctx.GlobalSet(key, strings.Join(s[:], ","))
+				if err != nil {
+					return err
+				}
+			} else {
+				err := ctx.GlobalSet(key, value.(string))
+				if err != nil {
+					return err
+				}
 			}
 		}
 	}