feat: Bundle assets in binary using go:embed (#340)

Fixes #47

config/config_test.go

@@ -17,7 +17,6 @@ import (
 	"github.com/TwiN/gatus/v4/alerting/provider/telegram"
 	"github.com/TwiN/gatus/v4/alerting/provider/twilio"
 	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v4/config/ui"
 	"github.com/TwiN/gatus/v4/config/web"
 	"github.com/TwiN/gatus/v4/core"
 	"github.com/TwiN/gatus/v4/storage"
@@ -39,10 +38,6 @@ func TestLoadDefaultConfigurationFile(t *testing.T) {
 
 func TestParseAndValidateConfigBytes(t *testing.T) {
 	file := t.TempDir() + "/test.db"
-	ui.StaticFolder = "../web/static"
-	defer func() {
-		ui.StaticFolder = "./web/static"
-	}()
 	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
 storage:
   type: sqlite

config/ui/ui.go

@@ -4,6 +4,8 @@ import (
 	"bytes"
 	"errors"
 	"html/template"
+
+	"github.com/TwiN/gatus/v4/web"
 )
 
 const (
@@ -14,10 +16,6 @@ const (
 )
 
 var (
-	// StaticFolder is the path to the location of the static folder from the root path of the project
-	// The only reason this is exposed is to allow running tests from a different path than the root path of the project
-	StaticFolder = "./web/static"
-
 	ErrButtonValidationFailed = errors.New("invalid button configuration: missing required name or link")
 )
 
@@ -71,7 +69,7 @@ func (cfg *Config) ValidateAndSetDefaults() error {
 		}
 	}
 	// Validate that the template works
-	t, err := template.ParseFiles(StaticFolder + "/index.html")
+	t, err := template.ParseFS(static.FileSystem, static.IndexPath)
 	if err != nil {
 		return err
 	}

config/ui/ui_test.go

@@ -6,10 +6,6 @@ import (
 )
 
 func TestConfig_ValidateAndSetDefaults(t *testing.T) {
-	StaticFolder = "../../web/static"
-	defer func() {
-		StaticFolder = "./web/static"
-	}()
 	cfg := &Config{
 		Title:  "",
 		Header: "",