Wait for memory to be reclaimed after node_e2e MemoryEviction test

This helps prevent interference with other tests that run immediately
after the MemoryEviction test.

test/e2e_node/memory_eviction_test.go

@@ -17,13 +17,18 @@ limitations under the License.
 package e2e_node
 
 import (
+	"encoding/json"
 	"fmt"
+	"io/ioutil"
+	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/stats"
 	"k8s.io/kubernetes/test/e2e/framework"
 
 	. "github.com/onsi/ginkgo"
@@ -96,6 +101,60 @@ var _ = framework.KubeDescribe("MemoryEviction [Slow] [Serial]", func() {
 
 			}, 60*time.Minute, 5*time.Second).Should(Equal(true))
 
+			// Wait for available memory to decrease to a reasonable level before ending the test.
+			// This prevents interference with tests that start immediately after this one.
+			Eventually(func() bool {
+				glog.Infof("Waiting for available memory to decrease to a reasonable level before ending the test.")
+
+				summary := stats.Summary{}
+				client := &http.Client{}
+				req, err := http.NewRequest("GET", "http://localhost:10255/stats/summary", nil)
+				if err != nil {
+					glog.Warningf("Failed to build http request: %v", err)
+					return false
+				}
+				req.Header.Add("Accept", "application/json")
+				resp, err := client.Do(req)
+				if err != nil {
+					glog.Warningf("Failed to get /stats/summary: %v", err)
+					return false
+				}
+				contentsBytes, err := ioutil.ReadAll(resp.Body)
+				if err != nil {
+					glog.Warningf("Failed to read /stats/summary: %+v", resp)
+					return false
+				}
+				contents := string(contentsBytes)
+				decoder := json.NewDecoder(strings.NewReader(contents))
+				err = decoder.Decode(&summary)
+				if err != nil {
+					glog.Warningf("Failed to parse /stats/summary to go struct: %+v", resp)
+					return false
+				}
+				if summary.Node.Memory.AvailableBytes == nil {
+					glog.Warningf("summary.Node.Memory.AvailableBytes was nil, cannot get memory stats.")
+					return false
+				}
+				if summary.Node.Memory.WorkingSetBytes == nil {
+					glog.Warningf("summary.Node.Memory.WorkingSetBytes was nil, cannot get memory stats.")
+					return false
+				}
+				avail := *summary.Node.Memory.AvailableBytes
+				wset := *summary.Node.Memory.WorkingSetBytes
+
+				// memory limit = avail + wset
+				limit := avail + wset
+				halflimit := limit / 2
+
+				// Wait for at least half of memory limit to be available
+				glog.Infof("Current available memory is: %d bytes. Waiting for at least %d bytes available.", avail, halflimit)
+				if avail >= halflimit {
+					return true
+				}
+
+				return false
+			}, 5*time.Minute, 5*time.Second).Should(Equal(true))
+
 		})
 	})