tsk-4: Adding CORS support (#53)

Closes #4

Reviewed-on: phoenix/textsender-api#53
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/config/config.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 
 	"git.kundeng.us/phoenix/textsender-models/tx0/config"
 	"github.com/joho/godotenv"
@@ -18,6 +19,7 @@ type Config struct {
 	ResetDB      bool
 	JWTSecret    string `env:"JWT_SECRET" required:"true"`
 	TwilioConfig *config.TwiloConfig
+	AllowedOrigins []string
 }
 
 type ConnectionInfo struct {
@@ -68,11 +70,13 @@ func Load() (*Config, *config.TwiloConfig, error) {
 	if cfg, err := TwilioConfig(); err != nil {
 		return nil, nil, err
 	} else {
+		allowedOrigins := unpackAllowedOrigins()
 		return &Config{
 			DBConnString: dbConnString,
 			ServerPort:   *port,
 			ResetDB:      *resetDb,
 			JWTSecret:    os.Getenv("JWT_SECRET"),
+			AllowedOrigins: allowedOrigins,
 		}, cfg, nil
 	}
 }
@@ -128,6 +132,12 @@ func UnpackDBConnString() (connInfo ConnectionInfo) {
 	return
 }
 
+func unpackAllowedOrigins() []string {
+	allowedOriginsRaw := os.Getenv("ALLOWED_ORIGINS")
+	allowedOriginsSplit := strings.Split(allowedOriginsRaw, ",")
+	return allowedOriginsSplit
+}
+
 func TwilioConfig() (*config.TwiloConfig, error) {
 	authSid := os.Getenv("TWILIO_AUTH_SID")
 	serviceSid := os.Getenv("TWILIO_SERVICE_SID")