Kubetest2 - Setup SSH keys for GCE

Originally I had thought we were relying on ssh keys mounted from a secret,
it turns out kubetest 1 generated the keys indirectly through gcloud.

This runs the same command as kubetest 1, creating and uploading the SSH keys.

tests/e2e/kubetest2-kops/deployer/common.go

@@ -27,6 +27,7 @@ import (
 	"time"
 
 	"k8s.io/klog/v2"
+	"k8s.io/kops/tests/e2e/kubetest2-kops/gce"
 	"k8s.io/kops/tests/e2e/pkg/kops"
 	"k8s.io/kops/tests/e2e/pkg/target"
 	"sigs.k8s.io/kubetest2/pkg/boskos"
@@ -74,14 +75,6 @@ func (d *deployer) initialize() error {
 			d.SSHPublicKeyPath = os.Getenv("AWS_SSH_PUBLIC_KEY_FILE")
 		}
 	case "gce":
-		// These environment variables are defined by the "preset-k8s-ssh" prow preset
-		// https://github.com/kubernetes/test-infra/blob/432c6e7dca38f0785901a6159275524cec369c4a/config/prow/config.yaml#L639-L656
-		if d.SSHPrivateKeyPath == "" {
-			d.SSHPrivateKeyPath = os.Getenv("JENKINS_GCE_SSH_PRIVATE_KEY_FILE")
-		}
-		if d.SSHPublicKeyPath == "" {
-			d.SSHPublicKeyPath = os.Getenv("JENKINS_GCE_SSH_PUBLIC_KEY_FILE")
-		}
 		if d.GCPProject == "" {
 			klog.V(1).Info("No GCP project provided, acquiring from Boskos")
 
@@ -103,6 +96,15 @@ func (d *deployer) initialize() error {
 			}
 			d.GCPProject = resource.Name
 			klog.V(1).Infof("Got project %s from boskos", d.GCPProject)
+
+			if d.SSHPrivateKeyPath == "" && d.SSHPublicKeyPath == "" {
+				privateKey, publicKey, err := gce.SetupSSH(d.GCPProject)
+				if err != nil {
+					return err
+				}
+				d.SSHPrivateKeyPath = privateKey
+				d.SSHPublicKeyPath = publicKey
+			}
 		}
 	}
 	if d.SSHUser == "" {

tests/e2e/kubetest2-kops/gce/ssh.go

@@ -0,0 +1,53 @@
+/*
+Copyright 2021 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 gce
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"k8s.io/klog/v2"
+	"sigs.k8s.io/kubetest2/pkg/exec"
+)
+
+func SetupSSH(project string) (string, string, error) {
+	dir, err := os.MkdirTemp("kops", "ssh")
+	if err != nil {
+		return "", "", err
+	}
+
+	privateKey := filepath.Join(dir, "key")
+	configArgs := []string{
+		"gcloud",
+		"compute",
+		fmt.Sprintf("--project=%v", project),
+		"config-ssh",
+		fmt.Sprintf("--ssh-key-file=%v", privateKey),
+	}
+	klog.Info(strings.Join(configArgs, " "))
+	cmd := exec.Command(configArgs[0], configArgs[1:]...)
+
+	exec.InheritOutput(cmd)
+	err = cmd.Run()
+	if err != nil {
+		return "", "", err
+	}
+
+	return privateKey, fmt.Sprintf("%v.pub", privateKey), nil
+}