From 9212f7494018c687430b5249d3aee8bebc4918ce Mon Sep 17 00:00:00 2001
From: techschool <58562849+techschool@users.noreply.github.com>
Date: Sun, 10 Apr 2022 15:27:06 +0200
Subject: [PATCH] extract user-agent and client-ip from grpc metadata (#34)

Co-authored-by: phamlequang <phamlequang@gmail.com>
---
 gapi/metadata.go       | 43 ++++++++++++++++++++++++++++++++++++++++++
 gapi/rpc_login_user.go |  5 +++--
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 gapi/metadata.go

diff --git a/gapi/metadata.go b/gapi/metadata.go
new file mode 100644
index 00000000..3be03454
--- /dev/null
+++ b/gapi/metadata.go
@@ -0,0 +1,43 @@
+package gapi
+
+import (
+	"context"
+
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+)
+
+const (
+	grpcGatewayUserAgentHeader = "grpcgateway-user-agent"
+	userAgentHeader            = "user-agent"
+	xForwardedForHeader        = "x-forwarded-for"
+)
+
+type Metadata struct {
+	UserAgent string
+	ClientIP  string
+}
+
+func (server *Server) extractMetadata(ctx context.Context) *Metadata {
+	mtdt := &Metadata{}
+
+	if md, ok := metadata.FromIncomingContext(ctx); ok {
+		if userAgents := md.Get(grpcGatewayUserAgentHeader); len(userAgents) > 0 {
+			mtdt.UserAgent = userAgents[0]
+		}
+
+		if userAgents := md.Get(userAgentHeader); len(userAgents) > 0 {
+			mtdt.UserAgent = userAgents[0]
+		}
+
+		if clientIPs := md.Get(xForwardedForHeader); len(clientIPs) > 0 {
+			mtdt.ClientIP = clientIPs[0]
+		}
+	}
+
+	if p, ok := peer.FromContext(ctx); ok {
+		mtdt.ClientIP = p.Addr.String()
+	}
+
+	return mtdt
+}
diff --git a/gapi/rpc_login_user.go b/gapi/rpc_login_user.go
index 314162c5..774ea199 100644
--- a/gapi/rpc_login_user.go
+++ b/gapi/rpc_login_user.go
@@ -42,12 +42,13 @@ func (server *Server) LoginUser(ctx context.Context, req *pb.LoginUserRequest) (
 		return nil, status.Errorf(codes.Internal, "failed to create refresh token")
 	}
 
+	mtdt := server.extractMetadata(ctx)
 	session, err := server.store.CreateSession(ctx, db.CreateSessionParams{
 		ID:           refreshPayload.ID,
 		Username:     user.Username,
 		RefreshToken: refreshToken,
-		UserAgent:    "",
-		ClientIp:     "",
+		UserAgent:    mtdt.UserAgent,
+		ClientIp:     mtdt.ClientIP,
 		IsBlocked:    false,
 		ExpiresAt:    refreshPayload.ExpiredAt,
 	})