From ca67d0e6f5aa765a17d8b2b9e8d697f9be365782 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Sat, 4 Jun 2022 22:22:27 +0200
Subject: [PATCH] detect servers S3 implementation

---
 pkg/server/server.go | 34 ++++++++++++++++++++++++++++++++++
 pkg/server/setup.go  |  2 ++
 2 files changed, 36 insertions(+)

diff --git a/pkg/server/server.go b/pkg/server/server.go
index 7a8feab..c0c80d1 100644
--- a/pkg/server/server.go
+++ b/pkg/server/server.go
@@ -1,17 +1,31 @@
 package server
 
 import (
+	"net/http"
 	"net/url"
+	"strings"
 
 	"github.com/aws/aws-sdk-go/service/s3"
 	"github.com/stv0g/gose/pkg/config"
 )
 
+type Implementation string
+
+const (
+	ImplementationAWS                = "AmazonS3"
+	ImplementationMinio              = "MinIO"
+	ImplementationGoogleCloudStorage = "UploadServer"
+	ImplementationDigitalOceanSpaces = "DigitalOceanSpaces"
+	ImplementationUnknown            = "Unknown"
+)
+
 // Server is a abstraction of an S3 server/bucket
 type Server struct {
 	*s3.S3
 
 	Config *config.S3Server
+
+	Implementation Implementation
 }
 
 // GetURL returns the full endpoint URL of the S3 server
@@ -53,3 +67,23 @@ func (s *Server) GetExpirationClass(cls string) *config.Expiration {
 
 	return nil
 }
+
+func (s *Server) DetectImplementation() Implementation {
+	if strings.Contains(s.Config.Endpoint, "digitaloceanspaces.com") {
+		return ImplementationDigitalOceanSpaces
+	} else if strings.Contains(s.Config.Endpoint, "storage.googleapis.com") {
+		return ImplementationGoogleCloudStorage
+	} else {
+		u := s.GetObjectURL("not-existing")
+
+		if r, err := http.Get(u.String()); err != nil {
+			return ImplementationUnknown
+		} else {
+			if svr := r.Header.Get("Server"); svr == "" {
+				return ImplementationUnknown
+			} else {
+				return Implementation(svr)
+			}
+		}
+	}
+}
diff --git a/pkg/server/setup.go b/pkg/server/setup.go
index 3196155..6588be9 100644
--- a/pkg/server/setup.go
+++ b/pkg/server/setup.go
@@ -9,6 +9,8 @@ import (
 
 // Setup initializes the S3 bucket (life-cycle rules & CORS)
 func (s *Server) Setup() error {
+	s.Implementation = s.DetectImplementation()
+
 	// Create bucket if it does not exist yet
 	if _, err := s.GetBucketPolicy(&s3.GetBucketPolicyInput{
 		Bucket: aws.String(s.Config.Bucket),