From 439cb3e74f0d288e10a95d0d610160336a602d94 Mon Sep 17 00:00:00 2001
From: Adam Worrall <abw@google.com>
Date: Tue, 27 Jun 2017 17:11:32 -0700
Subject: [PATCH] Log the OS images used during cluster creation

---
 test/e2e/e2e.go                      |  5 ++
 test/e2e/framework/google_compute.go | 97 ++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+)

diff --git a/test/e2e/e2e.go b/test/e2e/e2e.go
index 8b2158a9999..b1dab7e0979 100644
--- a/test/e2e/e2e.go
+++ b/test/e2e/e2e.go
@@ -118,6 +118,11 @@ var _ = ginkgo.SynchronizedBeforeSuite(func() []byte {
 		framework.Failf("Failed to setup provider config: %v", err)
 	}
 
+	switch framework.TestContext.Provider {
+	case "gce", "gke":
+		framework.LogClusterImageSources()
+	}
+
 	c, err := framework.LoadClientset()
 	if err != nil {
 		glog.Fatal("Error loading client: ", err)
diff --git a/test/e2e/framework/google_compute.go b/test/e2e/framework/google_compute.go
index 726726b397a..8b6fbedfe19 100644
--- a/test/e2e/framework/google_compute.go
+++ b/test/e2e/framework/google_compute.go
@@ -17,8 +17,11 @@ limitations under the License.
 package framework
 
 import (
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"os/exec"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"time"
@@ -96,3 +99,97 @@ func DeleteGCEStaticIP(name string) error {
 	}
 	return nil
 }
+
+// Returns master & node image string, or error
+func lookupClusterImageSources() (string, string, error) {
+	// Given args for a gcloud compute command, run it with other args, and return the values,
+	// whether separated by newlines, commas or semicolons.
+	gcloudf := func(argv ...string) ([]string, error) {
+		args := []string{"compute"}
+		args = append(args, argv...)
+		args = append(args, "--project", TestContext.CloudConfig.ProjectID,
+			"--zone", TestContext.CloudConfig.Zone)
+		outputBytes, err := exec.Command("gcloud", args...).CombinedOutput()
+		str := strings.Replace(string(outputBytes), ",", "\n", -1)
+		str = strings.Replace(str, ";", "\n", -1)
+		lines := strings.Split(str, "\n")
+		if err != nil {
+			Logf("lookupDiskImageSources: gcloud error with [%#v]; err:%v", argv, err)
+			for _, l := range lines {
+				Logf(" > %s", l)
+			}
+		}
+		return lines, err
+	}
+
+	// Given a GCE instance, look through its disks, finding one that has a sourceImage
+	host2image := func(instance string) (string, error) {
+		// gcloud compute instances describe {INSTANCE} --format="get(disks[].source)"
+		// gcloud compute disks describe {DISKURL} --format="get(sourceImage)"
+		disks, err := gcloudf("instances", "describe", instance, "--format=get(disks[].source)")
+		if err != nil {
+			return "", err
+		} else if len(disks) == 0 {
+			return "", fmt.Errorf("instance %q had no findable disks", instance)
+		}
+		// Loop over disks, looking for the boot disk
+		for _, disk := range disks {
+			lines, err := gcloudf("disks", "describe", disk, "--format=get(sourceImage)")
+			if err != nil {
+				return "", err
+			} else if len(lines) > 0 && lines[0] != "" {
+				return lines[0], nil // break, we're done
+			}
+		}
+		return "", fmt.Errorf("instance %q had no disk with a sourceImage", instance)
+	}
+
+	// gcloud compute instance-groups list-instances {GROUPNAME} --format="get(instance)"
+	nodeName := ""
+	instGroupName := strings.Split(TestContext.CloudConfig.NodeInstanceGroup, ",")[0]
+	if lines, err := gcloudf("instance-groups", "list-instances", instGroupName, "--format=get(instance)"); err != nil {
+		return "", "", err
+	} else if len(lines) == 0 {
+		return "", "", fmt.Errorf("no instances inside instance-group %q", instGroupName)
+	} else {
+		nodeName = lines[0]
+	}
+
+	nodeImg, err := host2image(nodeName)
+	if err != nil {
+		return "", "", err
+	}
+	frags := strings.Split(nodeImg, "/")
+	nodeImg = frags[len(frags)-1]
+
+	masterName := TestContext.CloudConfig.MasterName
+	masterImg, err := host2image(masterName)
+	if err != nil {
+		return "", "", err
+	}
+	frags = strings.Split(masterImg, "/")
+	masterImg = frags[len(frags)-1]
+
+	return masterImg, nodeImg, nil
+}
+
+func LogClusterImageSources() {
+	masterImg, nodeImg, err := lookupClusterImageSources()
+	if err != nil {
+		Logf("Cluster image sources lookup failed: %v\n", err)
+		return
+	}
+	Logf("cluster-master-image: %s", masterImg)
+	Logf("cluster-node-image: %s", nodeImg)
+
+	images := map[string]string{
+		"master_os_image": masterImg,
+		"node_os_image":   nodeImg,
+	}
+
+	outputBytes, _ := json.MarshalIndent(images, "", "  ")
+	filePath := filepath.Join(TestContext.OutputDir, "images.json")
+	if err := ioutil.WriteFile(filePath, outputBytes, 0644); err != nil {
+		Logf("cluster images sources, could not write to %q: %v", filePath, err)
+	}
+}