dept: refactor common parts of proxy setup for exec and port-forward

chore: update callers

internal/api/v1/application/exec.go

@@ -13,17 +13,13 @@ package application
 
 import (
 	"net/http"
-	"net/http/httputil"
-	"time"
 
 	"github.com/epinio/epinio/helpers/kubernetes"
 	"github.com/epinio/epinio/internal/application"
 	apierror "github.com/epinio/epinio/pkg/api/core/v1/errors"
 	"github.com/gin-gonic/gin"
 	v1 "k8s.io/api/core/v1"
-	thekubernetes "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
-	"k8s.io/client-go/rest"
 )
 
 func (hc Controller) Exec(c *gin.Context) apierror.APIErrors {
@@ -37,11 +33,6 @@ func (hc Controller) Exec(c *gin.Context) apierror.APIErrors {
 		return apierror.InternalError(err)
 	}
 
-	clientSetHTTP1, err := kubernetes.GetHTTP1Client(ctx)
-	if err != nil {
-		return apierror.InternalError(err)
-	}
-
 	app, err := application.Lookup(ctx, cluster, namespace, appName)
 	if err != nil {
 		return apierror.InternalError(err)
@@ -87,41 +78,22 @@ func (hc Controller) Exec(c *gin.Context) apierror.APIErrors {
 		return apierror.InternalError(err)
 	}
 
-	proxyRequest(c.Writer, c.Request, podToConnect, namespace, appData.Name, clientSetHTTP1)
-
-	return nil
-}
-
-func proxyRequest(rw http.ResponseWriter, req *http.Request, podName, namespace, container string, client thekubernetes.Interface) {
 	// https://github.com/kubernetes/kubectl/blob/2acffc93b61e483bd26020df72b9aef64541bd56/pkg/cmd/exec/exec.go#L352
-	attachURL := client.CoreV1().RESTClient().
+	attachURL := cluster.Kubectl.CoreV1().RESTClient().
 		Post().
 		Namespace(namespace).
 		Resource("pods").
-		Name(podName).
+		Name(podToConnect).
 		SubResource("exec").
 		VersionedParams(&v1.PodExecOptions{
 			Stdin:     true,
 			Stdout:    true,
 			Stderr:    true,
 			TTY:       true,
-			Container: container,
+			Container: appData.Name,
 			// https://github.com/rancher/dashboard/blob/37f40d7213ff32096bfefd02de77be6a0e7f40ab/components/nav/WindowManager/ContainerShell.vue#L22
 			Command: []string{"/bin/sh", "-c", "TERM=xterm-256color; export TERM; exec /bin/bash"},
 		}, scheme.ParameterCodec).URL()
 
-	httpClient := client.CoreV1().RESTClient().(*rest.RESTClient).Client
-	p := httputil.ReverseProxy{
-		Director: func(req *http.Request) {
-			req.URL = attachURL
-			req.Host = attachURL.Host
-			// let kube authentication work
-			delete(req.Header, "Cookie")
-			delete(req.Header, "Authorization")
-		},
-		Transport:     httpClient.Transport,
-		FlushInterval: time.Millisecond * 100,
-	}
-
-	p.ServeHTTP(rw, req)
+	return runProxy(ctx, c.Writer, c.Request, attachURL)
 }

internal/api/v1/application/portforward.go

@@ -13,15 +13,11 @@ package application
 
 import (
 	"net/http"
-	"net/http/httputil"
-	"time"
 
 	"github.com/epinio/epinio/helpers/kubernetes"
 	"github.com/epinio/epinio/internal/application"
 	apierror "github.com/epinio/epinio/pkg/api/core/v1/errors"
 	"github.com/gin-gonic/gin"
-	thekubernetes "k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/rest"
 )
 
 func (hc Controller) PortForward(c *gin.Context) apierror.APIErrors {
@@ -35,11 +31,6 @@ func (hc Controller) PortForward(c *gin.Context) apierror.APIErrors {
 		return apierror.InternalError(err)
 	}
 
-	clientSetHTTP1, err := kubernetes.GetHTTP1Client(ctx)
-	if err != nil {
-		return apierror.InternalError(err)
-	}
-
 	app, err := application.Lookup(ctx, cluster, namespace, appName)
 	if err != nil {
 		return apierror.InternalError(err)
@@ -80,33 +71,14 @@ func (hc Controller) PortForward(c *gin.Context) apierror.APIErrors {
 		podToConnect = podNames[0]
 	}
 
-	forwardRequest(c.Writer, c.Request, podToConnect, namespace, clientSetHTTP1)
-
-	return nil
-}
-
-func forwardRequest(rw http.ResponseWriter, req *http.Request, podName, namespace string, client thekubernetes.Interface) {
 	// https://github.com/kubernetes/kubectl/blob/2acffc93b61e483bd26020df72b9aef64541bd56/pkg/cmd/portforward/portforward.go#L409
-	forwardURL := client.CoreV1().RESTClient().
+	forwardURL := cluster.Kubectl.CoreV1().RESTClient().
 		Post().
 		Resource("pods").
 		Namespace(namespace).
-		Name(podName).
+		Name(podToConnect).
 		SubResource("portforward").
 		URL()
 
-	httpClient := client.CoreV1().RESTClient().(*rest.RESTClient).Client
-	p := httputil.ReverseProxy{
-		Director: func(req *http.Request) {
-			req.URL = forwardURL
-			req.Host = forwardURL.Host
-			// let kube authentication work
-			delete(req.Header, "Cookie")
-			delete(req.Header, "Authorization")
-		},
-		Transport:     httpClient.Transport,
-		FlushInterval: time.Millisecond * 100,
-	}
-
-	p.ServeHTTP(rw, req)
+	return runProxy(ctx, c.Writer, c.Request, forwardURL)
 }

internal/api/v1/application/proxy.go

@@ -0,0 +1,49 @@
+// Copyright © 2021 - 2023 SUSE LLC
+// 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 application
+
+import (
+	"context"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"time"
+
+	"github.com/epinio/epinio/helpers/kubernetes"
+	apierror "github.com/epinio/epinio/pkg/api/core/v1/errors"
+	"k8s.io/client-go/rest"
+)
+
+func runProxy(ctx context.Context, rw http.ResponseWriter, req *http.Request, destination *url.URL) apierror.APIErrors {
+	clientSetHTTP1, err := kubernetes.GetHTTP1Client(ctx)
+	if err != nil {
+		return apierror.InternalError(err)
+	}
+
+	httpClient := clientSetHTTP1.CoreV1().RESTClient().(*rest.RESTClient).Client
+
+	p := httputil.ReverseProxy{
+		Director: func(req *http.Request) {
+			req.URL = destination
+			req.Host = destination.Host
+			// let kube authentication work
+			delete(req.Header, "Cookie")
+			delete(req.Header, "Authorization")
+		},
+		Transport:     httpClient.Transport,
+		FlushInterval: time.Millisecond * 100,
+	}
+
+	p.ServeHTTP(rw, req)
+
+	return nil
+}