how to load toml settings (GOLANG) - postgresql

Question

I'm trying to use toml to store the connection settings of a database.
I want to load these settings that are in a config.toml file and thus do my operations
I tried the following:
go code:
func Init() *sql.DB {
config, err := toml.LoadFile("config.toml")
if err != nil {
log.Fatal("Erro ao carregar variaveis de ambiente")
}
host := config.Get("postgres.host").(string)
port := config.Get("postgres.port").(string)
user := config.Get("postgres.user").(string)
password := config.Get("postgres.password").(string)
dbname := config.Get("postgres.dbname").(string)
stringConnection := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s", host, port, user, password, dbname)
db, err := sql.Open("postgres", stringConnection)
if err != nil {
panic(err)
}
fmt.Println("Sucesso ao realizar conexão com o banco de dados")
err = db.Ping()
return db
}
config.toml:
[postgres]
host = "localhost"
port = 5432
user = "postgres"
password = "ivaneteJC"
dbname = "webhook"
this attempt is returning an error, which unfortunately I do not know how to proceed
error:
panic: interface conversion: interface {} is int64, not string
Any solution ?

Answer 1

As for your error, like #tkausl said, you define port as integer, and not a string, yet you do type assertion of the value to string in this line
port := config.Get("postgres.port").(string)
Change the string to int64 like the error said and you should be fine.
Are you using the https://github.com/pelletier/go-toml package? If so, this package seems to also support unmarshalling config files into Go struct directly. This is a more convenient approach instead of having to config.Get each config one by one.
type PostgreConfig struct {
Host string
Port int
User string
Password string
Dbname string
}
type MyConfig struct {
Postgres *PostgreConfig
}
// Read the toml file content
doc, err := os.ReadFile("config.toml")
if err != nil {
panic(err)
}
// Parse the content
var cfg MyConfig
err = toml.Unmarshal(doc, &cfg)
if err != nil {
panic(err)
}
fmt.Println(cfg.Postgres.Host)
fmt.Println(cfg.Postgres.Port)

Answer 2

The solution with minimal changes：
// solution 1
port := config.Get("postgres.port")
stringConnection := fmt.Sprintf("host=%s port=%v user=%s password=%s dbname=%s", host, port, user, password, dbname)
// solution 2
port := config.Get("postgres.port").(int64)
stringConnection := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s", host, port, user, password, dbname)
// solution 3
// config.toml
port = "5432"