From 6cdc2da4c20ca3161bceb2da62fa08c29c56c3bb Mon Sep 17 00:00:00 2001
From: Amritansh Amritansh <aamritan@redhat.com>
Date: Tue, 9 Jun 2026 11:31:21 +0530
Subject: [PATCH] Add agnhost-h2c-server

---
 test/images/agnhost/VERSION              |  2 +-
 test/images/agnhost/agnhost.go           |  2 +
 test/images/agnhost/h2c-server/server.go | 74 ++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 test/images/agnhost/h2c-server/server.go

diff --git a/test/images/agnhost/VERSION b/test/images/agnhost/VERSION
index e604dbd28b0..d1524d4046f 100644
--- a/test/images/agnhost/VERSION
+++ b/test/images/agnhost/VERSION
@@ -1 +1 @@
-2.63.0
+2.64.0
diff --git a/test/images/agnhost/agnhost.go b/test/images/agnhost/agnhost.go
index 088932e4e09..1ca954742d4 100644
--- a/test/images/agnhost/agnhost.go
+++ b/test/images/agnhost/agnhost.go
@@ -32,6 +32,7 @@ import (
 	"k8s.io/kubernetes/test/images/agnhost/fakeregistryserver"
 	grpchealthchecking "k8s.io/kubernetes/test/images/agnhost/grpc-health-checking"
 	"k8s.io/kubernetes/test/images/agnhost/guestbook"
+	h2cserver "k8s.io/kubernetes/test/images/agnhost/h2c-server"
 	"k8s.io/kubernetes/test/images/agnhost/inclusterclient"
 	"k8s.io/kubernetes/test/images/agnhost/liveness"
 	logsgen "k8s.io/kubernetes/test/images/agnhost/logs-generator"
@@ -94,6 +95,7 @@ func main() {
 	rootCmd.AddCommand(webhook.CmdWebhook)
 	rootCmd.AddCommand(openidmetadata.CmdTestServiceAccountIssuerDiscovery)
 	rootCmd.AddCommand(grpchealthchecking.CmdGrpcHealthChecking)
+	rootCmd.AddCommand(h2cserver.CmdH2CServer)
 	rootCmd.AddCommand(vishhstress.CmdStress)
 	rootCmd.AddCommand(podcertificatesigner.CmdPodCertificateSigner)
 	rootCmd.AddCommand(mtlsclient.CmdMtlsClient)
diff --git a/test/images/agnhost/h2c-server/server.go b/test/images/agnhost/h2c-server/server.go
new file mode 100644
index 00000000000..5ff22b903e5
--- /dev/null
+++ b/test/images/agnhost/h2c-server/server.go
@@ -0,0 +1,74 @@
+/*
+Copyright The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package h2cserver offers a tiny HTTP/2 cleartext (h2c) web server for probe testing.
+package h2cserver
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+
+	"github.com/spf13/cobra"
+	"golang.org/x/net/http2"
+)
+
+// CmdH2CServer is used by agnhost Cobra.
+var CmdH2CServer = &cobra.Command{
+	Use:   "h2c-server",
+	Short: "Starts a simple HTTP/2 cleartext (h2c) server",
+	Long:  "Starts a simple HTTP/2 cleartext server with prior knowledge on the given --port. Responds with 200 OK to all requests.",
+	Args:  cobra.MaximumNArgs(0),
+	Run:   main,
+}
+
+var (
+	port int
+)
+
+func init() {
+	CmdH2CServer.Flags().IntVar(&port, "port", 80, "Port number.")
+}
+
+func main(cmd *cobra.Command, args []string) {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+		w.WriteHeader(http.StatusOK)
+		_, _ = fmt.Fprintf(w, "ok")
+	})
+
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+	if err != nil {
+		log.Fatalf("Error from net.Listen(): %s", err)
+	}
+
+	h2s := &http2.Server{}
+	srv := &http.Server{Handler: handler}
+
+	log.Printf("Serving h2c on port %d.\n", port)
+
+	for {
+		c, err := l.Accept()
+		if err != nil {
+			log.Fatalf("Error from Accept(): %s", err)
+		}
+		go h2s.ServeConn(c, &http2.ServeConnOpts{
+			Handler:    handler,
+			BaseConfig: srv,
+		})
+	}
+}