Merge pull request #46738 from bdbauer/mysql

Automatic merge from submit-queue

StatefulSet upgrade test - replicated database (mysql)

**What this PR does / why we need it**:
Adds a new upgrade test. The test creates a statefulset with a replicated mysql database. It populates the database and then continually polls the data while performing an upgrade. 

Ultimately, this PR increases confidence of reliability during upgrades. It helps show that StatefulSets and Pod Disruption Budgets are doing what they're supposed to.  Code to pay attention to this was added for #38336.

Also vendors in a golang mysql client driver, for use in the test.

**Release note**:
```release-note
NONE
```

test/e2e/testing-manifests/statefulset/mysql-upgrade/configmap.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: mysql
+  labels:
+    app: mysql
+data:
+  master.cnf: |
+    [mysqld]
+    log-bin
+  slave.cnf: |
+    [mysqld]
+    super-read-only

test/e2e/testing-manifests/statefulset/mysql-upgrade/service.yaml

@@ -0,0 +1,27 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: mysql
+  labels:
+    app: mysql
+spec:
+  ports:
+  - name: mysql
+    port: 3306
+  clusterIP: None
+  selector:
+    app: mysql
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: mysql-read
+  labels:
+    app: mysql
+spec:
+  ports:
+  - name: mysql
+    port: 3306
+  selector:
+      app: mysql
+  type: LoadBalancer

test/e2e/testing-manifests/statefulset/mysql-upgrade/statefulset.yaml

@@ -0,0 +1,159 @@
+apiVersion: apps/v1beta1
+kind: StatefulSet
+metadata:
+  name: mysql
+spec:
+  serviceName: mysql
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: mysql
+      annotations:
+        pod.beta.kubernetes.io/init-containers: '[
+          {
+            "name": "init-mysql",
+            "image": "mysql:5.7",
+            "command": ["bash", "-c", "
+              set -ex\n
+              [[ `hostname` =~ -([0-9]+)$ ]] || exit 1\n
+              ordinal=${BASH_REMATCH[1]}\n
+              echo [mysqld] > /mnt/conf.d/server-id.cnf\n
+              echo server-id=$((100 + $ordinal)) >> /mnt/conf.d/server-id.cnf\n
+              if [[ $ordinal -eq 0 ]]; then\n
+                cp /mnt/config-map/master.cnf /mnt/conf.d/\n
+              else\n
+                cp /mnt/config-map/slave.cnf /mnt/conf.d/\n
+              fi\n
+            "],
+            "volumeMounts": [
+              {"name": "conf", "mountPath": "/mnt/conf.d"},
+              {"name": "config-map", "mountPath": "/mnt/config-map"}
+            ]
+          },
+          {
+            "name": "clone-mysql",
+            "image": "gcr.io/google-samples/xtrabackup:1.0",
+            "command": ["bash", "-c", "
+              set -ex\n
+              [[ -d /var/lib/mysql/mysql ]] && exit 0\n
+              [[ `hostname` =~ -([0-9]+)$ ]] || exit 1\n
+              ordinal=${BASH_REMATCH[1]}\n
+              [[ $ordinal -eq 0 ]] && exit 0\n
+              ncat --recv-only mysql-$(($ordinal-1)).mysql 3307 | xbstream -x -C /var/lib/mysql\n
+              xtrabackup --prepare --target-dir=/var/lib/mysql\n
+            "],
+            "volumeMounts": [
+              {"name": "data", "mountPath": "/var/lib/mysql", "subPath": "mysql"},
+              {"name": "conf", "mountPath": "/etc/mysql/conf.d"}
+            ]
+          }
+        ]'
+    spec:
+      containers:
+      - name: mysql
+        image: mysql:5.7.15
+        env:
+        - name: MYSQL_ALLOW_EMPTY_PASSWORD
+          value: "1"
+        ports:
+        - name: mysql
+          containerPort: 3306
+        volumeMounts:
+        - name: data
+          mountPath: /var/lib/mysql
+          subPath: mysql
+        - name: conf
+          mountPath: /etc/mysql/conf.d
+        resources:
+          requests:
+            cpu: 1
+            memory: 1Gi
+        livenessProbe:
+          exec:
+            command: ["mysqladmin", "ping"]
+          initialDelaySeconds: 30
+          timeoutSeconds: 5
+        readinessProbe:
+          exec:
+            command: ["mysql", "-h", "127.0.0.1", "-e", "SELECT 1"]
+          initialDelaySeconds: 5
+          timeoutSeconds: 1
+      - name: xtrabackup
+        image: gcr.io/google-samples/xtrabackup:1.0
+        ports:
+        - name: xtrabackup
+          containerPort: 3307
+        command:
+        - bash
+        - "-c"
+        - |
+          set -ex
+          cd /var/lib/mysql
+
+          if [[ -f xtrabackup_slave_info ]]; then
+            mv xtrabackup_slave_info change_master_to.sql.in
+            rm -f xtrabackup_binlog_info
+          elif [[ -f xtrabackup_binlog_info ]]; then
+            [[ `cat xtrabackup_binlog_info` =~ ^(.*?)[[:space:]]+(.*?)$ ]] || exit 1
+            rm xtrabackup_binlog_info
+            echo "CHANGE MASTER TO MASTER_LOG_FILE='${BASH_REMATCH[1]}',\
+                  MASTER_LOG_POS=${BASH_REMATCH[2]}" > change_master_to.sql.in
+          fi
+
+          if [[ -f change_master_to.sql.in ]]; then
+            echo "Waiting for mysqld to be ready (accepting connections)"
+            until mysql -h 127.0.0.1 -e "SELECT 1"; do sleep 1; done
+
+            echo "Initializing replication from clone position"
+            mv change_master_to.sql.in change_master_to.sql.orig
+            mysql -h 127.0.0.1 <<EOF
+          $(<change_master_to.sql.orig),
+            MASTER_HOST='mysql-0.mysql',
+            MASTER_USER='root',
+            MASTER_PASSWORD='',
+            MASTER_CONNECT_RETRY=10;
+          START SLAVE;
+          EOF
+          fi
+
+          exec ncat --listen --keep-open --send-only --max-conns=1 3307 -c \
+            "xtrabackup --backup --slave-info --stream=xbstream --host=127.0.0.1 --user=root"
+        volumeMounts:
+        - name: data
+          mountPath: /var/lib/mysql
+          subPath: mysql
+        - name: conf
+          mountPath: /etc/mysql/conf.d
+        resources:
+          requests:
+            cpu: 100m
+            memory: 100Mi
+      volumes:
+      - name: conf
+        emptyDir: {}
+      - name: config-map
+        configMap:
+          name: mysql
+  volumeClaimTemplates:
+  - metadata:
+      name: data
+      annotations:
+        volume.alpha.kubernetes.io/storage-class: default
+    spec:
+      accessModes: ["ReadWriteOnce"]
+      resources:
+        requests:
+          storage: 10Gi
+---
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+ name: mysql-pdb 
+ labels:
+   pdb: mysql
+spec:
+ minAvailable: 2
+ selector:
+   matchLabels:
+     app: mysql

test/e2e/testing-manifests/statefulset/mysql-upgrade/tester.yaml

@@ -0,0 +1,48 @@
+apiVersion: apps/v1beta1
+kind: Deployment
+metadata:
+  name: mysql-test-server
+spec:
+  replicas: 3
+  template:
+    metadata:
+      labels:
+        app: test-server
+    spec:
+      containers:
+      - name: test-server
+        image: gcr.io/google-containers/mysql-e2e-test:0.1
+        imagePullPolicy: Always
+        ports:
+        - containerPort: 8080
+        readinessProbe:
+          httpGet:
+            path: /healthz
+            port: 8080
+          initialDelaySeconds: 2
+          periodSeconds: 2
+---
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: tester-pdb
+  labels:
+    pdb: test-server
+spec:
+  minAvailable: 1
+  selector:
+    matchLabels:
+      app: test-server
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: test-server
+  name: test-server
+spec:
+  ports:
+    - port: 8080
+  selector:
+    app: test-server
+  type: LoadBalancer

test/e2e/upgrades/BUILD

@@ -18,6 +18,7 @@ go_library(
         "horizontal_pod_autoscalers.go",
         "ingress.go",
         "job.go",
+        "mysql.go",
         "persistent_volumes.go",
         "secrets.go",
         "services.go",

test/e2e/upgrades/mysql.go

@@ -0,0 +1,209 @@
+/*
+Copyright 2017 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 upgrades
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"path/filepath"
+	"strconv"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/kubernetes/pkg/util/version"
+	"k8s.io/kubernetes/test/e2e/framework"
+)
+
+const mysqlManifestPath = "test/e2e/testing-manifests/statefulset/mysql-upgrade"
+
+// MySqlUpgradeTest implements an upgrade test harness that polls a replicated sql database.
+type MySqlUpgradeTest struct {
+	ip               string
+	successfulWrites int
+	nextWrite        int
+	ssTester         *framework.StatefulSetTester
+}
+
+func (MySqlUpgradeTest) Name() string { return "mysql-upgrade" }
+
+func (MySqlUpgradeTest) Skip(upgCtx UpgradeContext) bool {
+	minVersion := version.MustParseSemantic("1.5.0")
+
+	for _, vCtx := range upgCtx.Versions {
+		if vCtx.Version.LessThan(minVersion) {
+			return true
+		}
+	}
+	return false
+}
+
+func mysqlKubectlCreate(ns, file string) {
+	path := filepath.Join(framework.TestContext.RepoRoot, mysqlManifestPath, file)
+	framework.RunKubectlOrDie("create", "-f", path, fmt.Sprintf("--namespace=%s", ns))
+}
+
+func (t *MySqlUpgradeTest) getServiceIP(f *framework.Framework, ns, svcName string) string {
+	svc, err := f.ClientSet.CoreV1().Services(ns).Get(svcName, metav1.GetOptions{})
+	Expect(err).NotTo(HaveOccurred())
+	ingress := svc.Status.LoadBalancer.Ingress
+	if len(ingress) == 0 {
+		return ""
+	}
+	return ingress[0].IP
+}
+
+// Setup creates a StatefulSet, HeadlessService, a Service to write to the db, and a Service to read
+// from the db. It then connects to the db with the write Service and populates the db with a table
+// and a few entries. Finally, it connects to the db with the read Service, and confirms the data is
+// available. The db connections are left open to be used later in the test.
+func (t *MySqlUpgradeTest) Setup(f *framework.Framework) {
+	ns := f.Namespace.Name
+	statefulsetPoll := 30 * time.Second
+	statefulsetTimeout := 10 * time.Minute
+	t.ssTester = framework.NewStatefulSetTester(f.ClientSet)
+
+	By("Creating a configmap")
+	mysqlKubectlCreate(ns, "configmap.yaml")
+
+	By("Creating a mysql StatefulSet")
+	t.ssTester.CreateStatefulSet(mysqlManifestPath, ns)
+
+	By("Creating a mysql-test-server deployment")
+	mysqlKubectlCreate(ns, "tester.yaml")
+
+	By("Getting the ingress IPs from the test-service")
+	err := wait.PollImmediate(statefulsetPoll, statefulsetTimeout, func() (bool, error) {
+		if t.ip = t.getServiceIP(f, ns, "test-server"); t.ip == "" {
+			return false, nil
+		}
+		if _, err := t.countNames(); err != nil {
+			framework.Logf("Service endpoint is up but isn't responding")
+			return false, nil
+		}
+		return true, nil
+	})
+	Expect(err).NotTo(HaveOccurred())
+	framework.Logf("Service endpoint is up")
+
+	By("Adding 2 names to the database")
+	Expect(t.addName(strconv.Itoa(t.nextWrite))).NotTo(HaveOccurred())
+	Expect(t.addName(strconv.Itoa(t.nextWrite))).NotTo(HaveOccurred())
+
+	By("Verifying that the 2 names have been inserted")
+	count, err := t.countNames()
+	Expect(err).NotTo(HaveOccurred())
+	Expect(count).To(Equal(2))
+}
+
+// Test continually polls the db using the read and write connections, inserting data, and checking
+// that all the data is readable.
+func (t *MySqlUpgradeTest) Test(f *framework.Framework, done <-chan struct{}, upgrade UpgradeType) {
+	var writeSuccess, readSuccess, writeFailure, readFailure int
+	By("Continuously polling the database during upgrade.")
+	go wait.Until(func() {
+		_, err := t.countNames()
+		if err != nil {
+			framework.Logf("Error while trying to read data: %v", err)
+			readFailure++
+		} else {
+			readSuccess++
+		}
+	}, framework.Poll, done)
+
+	wait.Until(func() {
+		err := t.addName(strconv.Itoa(t.nextWrite))
+		if err != nil {
+			framework.Logf("Error while trying to write data: %v", err)
+			writeFailure++
+		} else {
+			writeSuccess++
+		}
+	}, framework.Poll, done)
+
+	t.successfulWrites = writeSuccess
+	framework.Logf("Successful reads: %d", readSuccess)
+	framework.Logf("Successful writes: %d", writeSuccess)
+	framework.Logf("Failed reads: %d", readFailure)
+	framework.Logf("Failed writes: %d", writeFailure)
+
+	// TODO: Not sure what the ratio defining a successful test run should be. At time of writing the
+	// test, failures only seem to happen when a race condition occurs (read/write starts, doesn't
+	// finish before upgrade interferes).
+
+	readRatio := float64(readSuccess) / float64(readSuccess+readFailure)
+	writeRatio := float64(writeSuccess) / float64(writeSuccess+writeFailure)
+	if readRatio < 0.75 {
+		framework.Failf("Too many failures reading data. Success ratio: %f", readRatio)
+	}
+	if writeRatio < 0.75 {
+		framework.Failf("Too many failures writing data. Success ratio: %f", writeRatio)
+	}
+}
+
+// Teardown performs one final check of the data's availability.
+func (t *MySqlUpgradeTest) Teardown(f *framework.Framework) {
+	count, err := t.countNames()
+	Expect(err).NotTo(HaveOccurred())
+	Expect(count >= t.successfulWrites).To(BeTrue())
+}
+
+// addName adds a new value to the db.
+func (t *MySqlUpgradeTest) addName(name string) error {
+	val := map[string][]string{"name": {name}}
+	t.nextWrite++
+	r, err := http.PostForm(fmt.Sprintf("http://%s:8080/addName", t.ip), val)
+	if err != nil {
+		return err
+	}
+	defer r.Body.Close()
+	if r.StatusCode != http.StatusOK {
+		b, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			return err
+		}
+		return fmt.Errorf(string(b))
+	}
+	return nil
+}
+
+// countNames checks to make sure the values in testing.users are available, and returns
+// the count of them.
+func (t *MySqlUpgradeTest) countNames() (int, error) {
+	r, err := http.Get(fmt.Sprintf("http://%s:8080/countNames", t.ip))
+	if err != nil {
+		return 0, err
+	}
+	defer r.Body.Close()
+	if r.StatusCode != http.StatusOK {
+		b, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			return 0, err
+		}
+		return 0, fmt.Errorf(string(b))
+	}
+	var count int
+	if err := json.NewDecoder(r.Body).Decode(&count); err != nil {
+		return 0, err
+	}
+	return count, nil
+}