How to read config.json in Go lang? - go

Question

I have used the following code in filLib.go:
func LoadConfiguration(filename string) (Configuration, error) {
bytes, err := ioutil.ReadFile(filename)
if err != nil {
return Configuration{}, err
}
var c Configuration
err = json.Unmarshal(bytes, &c)
if err != nil {
return Configuration{}, err
}
return c, nil
}
But ioutil.ReadFile(filename) return *os.PathError.
Both the files config.json and filLib.go are in same folder.

Answer 1

The path of *.go file is not directly relevant to the working directory of the executing compiled code. Verify where your code thinks it actually is (compare to where you think it should be :).
import(
"os"
"fmt"
"log"
)
func main() {
dir, err := os.Getwd()
if err != nil {
log.Fatal(err)
}
fmt.Println(dir)
}

Answer 2

The issue might be with the filename you're providing. Below is the code sample that working fine for me.
func loadConfig() {
var AppConfig Conf
raw, err := ioutil.ReadFile("conf/conf.json")
if err != nil {
log.Println("Error occured while reading config")
return
}
json.Unmarshal(raw, &AppConfig)
}

Answer 3

I found this library enter link description here
It is a very simple and easy to use configuration library, allowing Json based config files for your Go application. Configuration provider reads configuration data from config.json file. You can get the string value of a configuration, or bind an interface to a valid JSON section by related section name convention parameter.
Consider the following config.json file:
{
"ConnectionStrings": {
"DbConnection": "Server=.;User Id=app;Password=123;Database=Db",
"LogDbConnection": "Server=.;User Id=app;Password=123;Database=Log"
},
"Caching": {
"ApplicationKey": "key",
"Host": "127.0.01"
},
"Website": {
"ActivityLogEnable": "true",
"ErrorMessages": {
"InvalidTelephoneNumber": "Invalid Telephone Number",
"RequestNotFound": "Request Not Found",
"InvalidConfirmationCode": "Invalid Confirmation Code"
}
},
"Services": {
"List": [
{
"Id": 1,
"Name": "Service1"
},
{
"Id": 2,
"Name": "Service2"
},
{
"Id": 3,
"Name": "Service3"
}
]
}
}
The following code displays how to access some of the preceding configuration settings. You can get config value via GetSection function with specifying Json sections as string parameter split by ":"
c, err := jsonconfig.GetSection("ConnectionStrings:DbConnection")
Any valid Json is a valid configuration type. You can also bind a struct via jsonconfig. For example, Caching configuration can be bind to valid struct:
type Caching struct {
ApplicationKey string
Host string
}
var c Caching
err = jsonconfig.Bind(&c, "Caching")