Multitenant streams api (#72)

streams/handler/handler.go

@@ -1,6 +1,9 @@
 package handler
 
 import (
+	"fmt"
+	"regexp"
+	"strings"
 	"time"
 
 	"github.com/micro/micro/v3/service/errors"
@@ -11,6 +14,7 @@ import (
 var (
 	TokenTTL          = time.Minute
 	ErrMissingTopic   = errors.BadRequest("MISSING_TOPIC", "Missing topic")
+	ErrInvalidTopic   = errors.BadRequest("MISSING_TOPIC", "Invalid topic")
 	ErrMissingToken   = errors.BadRequest("MISSING_TOKEN", "Missing token")
 	ErrMissingMessage = errors.BadRequest("MISSING_MESSAGE", "Missing message")
 	ErrInvalidToken   = errors.Forbidden("INVALID_TOKEN", "Invalid token")
@@ -22,6 +26,7 @@ type Token struct {
 	Token     string `gorm:"primaryKey"`
 	Topic     string
 	ExpiresAt time.Time
+	Namespace string
 }
 
 type Streams struct {
@@ -29,3 +34,18 @@ type Streams struct {
 	Events events.Stream
 	Time   func() time.Time
 }
+
+// fmtTopic returns a topic string with namespace prefix and hyphens replaced with dots
+func fmtTopic(ns, topic string) string {
+	// events topic names can only be alphanumeric and "."
+	return fmt.Sprintf("%s.%s", strings.ReplaceAll(ns, "-", "."), topic)
+}
+
+// validateTopicInput validates that topic is alphanumeric
+func validateTopicInput(topic string) error {
+	reg := regexp.MustCompile("^[a-zA-Z0-9]+$")
+	if len(reg.FindString(topic)) == 0 {
+		return ErrInvalidTopic
+	}
+	return nil
+}