Adding support to configuration files and an example configuration file.

config.json

@@ -0,0 +1,13 @@
+{
+    "db": {
+        "engine": "postgres",
+        "user": "wwwshop",
+        "password": "wwwshop",
+        "host": "localhost",
+        "port": 5432,
+        "database": "wwwshop",
+        "options": {
+            "sslmode": "disable"
+        }
+    }
+}

wwwshop/config/config.go

@@ -0,0 +1,73 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strings"
+    "bytes"
+    "errors"
+)
+
+type Config struct {
+	DB DB `json:"db"`
+}
+
+type DB struct {
+	Engine   string `json:"engine"`
+	User     string `json:"user"`
+	Password string `json:"password"`
+	Host     string `json:"host"`
+	Port     int64  `json:"port"`
+	Database string `json:"database"`
+	Options  map[string]string
+}
+
+var search_dir = "."
+
+func New() (*Config, error) {
+	data, err := ioutil.ReadFile(strings.Join([]string{search_dir, "/config.json"}, ""))
+	if err != nil {
+		return nil, err
+	}
+	var config Config
+	decoder := json.NewDecoder(bytes.NewReader(data))
+	decoder.Decode(&config)
+	return &config, nil
+}
+
+func (self DB) GetURL() (*string, error) {
+	if !(CheckWord(self.Engine) && CheckWord(self.User) && CheckWord(self.Password) && CheckWord(self.Database) && CheckHost(self.Host)) {
+		return nil, errors.New("Database configuration doesn't pass the constraints.")
+	}
+	return_string := fmt.Sprintf("%s://%s:%s@%s:%d/%s", self.Engine, self.User, self.Password, self.Host, self.Port, self.Database)
+	if self.Options != nil && len(self.Options) > 0 {
+		return_string = strings.Join([]string{return_string, "?"}, "")
+		for key, value := range self.Options {
+			return_string = strings.Join([]string{
+				return_string,
+				strings.Join([]string{key, value}, "="),
+			}, "&")
+		}
+	}
+	return &return_string, nil
+}
+
+func CheckHost(word string) bool {
+	match, err := regexp.MatchString("^(\\w|\\.)+$", word)
+	if err != nil {
+		fmt.Println(err.Error())
+		return false
+	}
+	return match
+}
+
+func CheckWord(word string) bool {
+	match, err := regexp.MatchString("^\\w+$", word)
+	if err != nil {
+		fmt.Println(err.Error())
+		return false
+	}
+	return match
+}

wwwshop/dao/database/database.go

@@ -1,6 +1,7 @@
 package database
 
 import (
+	"WWWShop/wwwshop/config"
 	"database/sql"
 	"fmt"
 	"github.com/golang-migrate/migrate/v4"
@@ -12,7 +13,12 @@ import (
 )
 
 func DB() *sql.DB {
-	db, err := sql.Open("postgres", os.Getenv("DATABASE_URL"))
+	configuration, err := config.New()
+	url_postgres, err := configuration.DB.GetURL()
+    if err != nil {
+        log.Fatal(err)
+    }
+	db, err := sql.Open("postgres", *url_postgres)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
 		os.Exit(1)
@@ -30,6 +36,6 @@ func Migrate(db *sql.DB) {
 		log.Fatal(err)
 	}
 	if err := m.Up(); err != nil {
-		log.Fatal(err)
+        log.Println(err)
 	}
 }

wwwshop/wwwshop.go

@@ -4,6 +4,7 @@ import (
     "net/http"
     c "WWWShop/wwwshop/controller"
     u "WWWShop/wwwshop/controller/usercontroller"
+    d "WWWShop/wwwshop/dao/database"
 )
 
 type WWWShop struct {}
@@ -15,6 +16,7 @@ func New() WWWShop {
 
 
 func (self WWWShop) Init() {
+    d.Migrate(d.DB())
     user_controller := c.GenerateController(u.New())
     http.Handle("/user", user_controller)
     http.Handle("/user/", user_controller)