Added tls for http clients (#5766)

* Added global http client

* Added Do func for global http client

* Changed the code to use the global http client

* Fix http client in volume uploader

* Fixed pkg name

* Fixed http util funcs

* Fixed http client for bench_filer_upload

* Fixed http client for stress_filer_upload

* Fixed http client for filer_server_handlers_proxy

* Fixed http client for command_fs_merge_volumes

* Fixed http client for command_fs_merge_volumes and command_volume_fsck

* Fixed http client for s3api_server

* Added init global client for main funcs

* Rename global_client to client

* Changed:
- fixed NewHttpClient;
- added CheckIsHttpsClientEnabled func
- updated security.toml in scaffold

* Reduce the visibility of some functions in the util/http/client pkg

* Added the loadSecurityConfig function

* Use util.LoadSecurityConfiguration() in NewHttpClient func

weed/server/filer_server_handlers_proxy.go

@@ -3,24 +3,13 @@ package weed_server
 import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/security"
-	"github.com/seaweedfs/seaweedfs/weed/util"
 	"github.com/seaweedfs/seaweedfs/weed/util/mem"
 	"io"
 	"math/rand"
 	"net/http"
+	util_http "github.com/seaweedfs/seaweedfs/weed/util/http"
 )
 
-var (
-	client *http.Client
-)
-
-func init() {
-	client = &http.Client{Transport: &http.Transport{
-		MaxIdleConns:        1024,
-		MaxIdleConnsPerHost: 1024,
-	}}
-}
-
 func (fs *FilerServer) maybeAddVolumeJwtAuthorization(r *http.Request, fileId string, isWrite bool) {
 	encodedJwt := fs.maybeGetVolumeJwtAuthorizationToken(fileId, isWrite)
 
@@ -71,14 +60,14 @@ func (fs *FilerServer) proxyToVolumeServer(w http.ResponseWriter, r *http.Reques
 		}
 	}
 
-	proxyResponse, postErr := client.Do(proxyReq)
+	proxyResponse, postErr := util_http.GetGlobalHttpClient().Do(proxyReq)
 
 	if postErr != nil {
 		glog.Errorf("post to filer: %v", postErr)
 		w.WriteHeader(http.StatusInternalServerError)
 		return
 	}
-	defer util.CloseResponse(proxyResponse)
+	defer util_http.CloseResponse(proxyResponse)
 
 	for k, v := range proxyResponse.Header {
 		w.Header()[k] = v