♑️ 🆔 🌲 Apprendre à déployer des microservices. Partie 2. Kubernetes 🐂 🛶 👩‍👧‍👧

Bonjour, Habr!

Il s'agit de la deuxième partie d'une série d'articles «Apprendre à déployer des microservices». Dans la partie précédente, nous avons écrit 2 microservices simples - un backend et une passerelle, et avons compris comment les intégrer dans des images docker. Dans le même article, nous organiserons l'orchestration de nos conteneurs dockers à l'aide de Kubernetes. Nous allons configurer séquentiellement le lancement du système dans Minikube, puis l'adapter pour le déploiement dans le moteur Google Kubernetes.

Plan de série:

Création de services sur Spring Boot, collaboration avec Docker

Mots-clés: Java 11, Spring Boot, Docker, optimisation d'image
Développement du système de configuration et de déploiement de Kubernetes dans Google Kubernetes Engine

Mots-clés: Kubernetes, GKE, gestion des ressources, mise à l'échelle automatique, secrets
Création d'un graphique avec Helm 3 pour une gestion plus efficace des clusters

: Helm 3, chart deployment
Jenkins

: Jenkins configuration, plugins, separate configs repository

Kubernetes:

. , . , .
. , , .
. . .
. - , Docker-, Kubernetes , .
. ().

Kubernetes — , , . . Kubernetes- .

GitHub .

Kubernetes

Minikube — Kubernetes . . , , GKE. Google Cloud Platform - 300$ . 2+ (n1-standard-1).

Kubernetes

Kubernetes . . , .

Kubernetes:

Namespace — . , . .
Pod — . . , , , , .
ReplicaSet — , , . , . ReplicaSet — Deployment.
Deployment — , ReplicaSet'. .
Service — . , IP-. , . - , Service .

"" Kubernetes, .

. , . . , . :
- ClusterIP — . IP-, .
- NodePort — IP- ( ClusterIP) , . <NodeIP>:<NodePort>.
- LoadBalancer — NodePort , . IP- .
Kubernetes DNS , . .
ConfigMap — , , , .
Secret — . (№ SSL-), , base64- , . .
HorizontalPodAutoscaler — , .

Minikube configuration

Namespace:

kubectl create namespace msvc-ns

kubectl config set-context --current --namespace=msvc-ns

'msvc-ns'. , 'default'.

Kubernetes yaml- , CLI. yaml-.

ConfigMap

, . URL- . ConfigMap , ( ).

apiVersion: v1
kind: ConfigMap
metadata:
  name: urls-config
data:
  BACKEND_URL: "http://backend:8080/"

, Kubernetes . , 'backend' 8080 .

Secret

apiVersion: v1
kind: Secret
metadata:
  name: msvc-secret
type: Opaque
stringData:
  secret: secret

Opaque , -. , , Docker-, . stringData. base64, . :

data:
  secret: c2VjcmV0

Deployments

— .

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway
  labels:
    tier: gateway
    app: microservices
spec:
  replicas: 3
  selector:
    matchLabels:
      tier: gateway
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        tier: gateway
    spec:
      containers:
        - name: gateway
          image: anshelen/microservices-gateway:latest
          envFrom:
            - configMapRef:
                name: urls-config
          env:
            - name: SECRET
              valueFrom:
                secretKeyRef:
                  name: msvc-secret
                  key: secret
          readinessProbe:
              httpGet:
                path: /actuator/health
                port: 8080
              initialDelaySeconds: 5
              periodSeconds: 3
          ports:
            - containerPort: 8080
              protocol: TCP
          resources:
            limits:
              memory: "256Mi"
              cpu: "200m"
            requests:
              memory: "128Mi"
              cpu: "50m"

metadata.labels
, . , 'microservices' 'gateway'.
metadata.annotations — , .
spec.replicas
.
spec.selector.matchLabels
. , tier, 'backend'. spec.template , metadata.labels , .
spec.strategy
spec.strategy . 'rollingUpdate' , ReplicaSet, ReplicaSet', . ( / ) maxSurge maxUnavailable. , . spec.strategy , .
spec.templates
spec.templates .
spec.templates.metadata.labels
, spec.selector.matchLabels, "" .
spec.templates.spec.containers.image
. latest Docker-, , . , — Kubernetes. , . . 'latest' 4 , Jenkins.
spec.templates.spec.containers.envFrom.configMapRef
ConfigMap .
spec.templates.spec.containers.env
'SECRET', - 'secret'.
spec.templates.spec.containers.readinessProbe
. , . Kubernetes , 3 200, .

initialDelaySeconds — .
periodSeconds — .

livenessProbe, ( ).
spec.templates.spec.containers.ports
ports . ( -p 8080:8080).
spec.templates.spec.containers.resources
. limits — , requests — , . 200m — 200 ( ), Mi — .

, , .

Services

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: backend
  name: backend
spec:
  ports:
    - port: 8080
      protocol: TCP
      targetPort: 8080
  selector:
    tier: backend

spec.ports.targetPort — , spec.ports.port — . spec.selector , , tier, 'backend'. , ClusterIP, http://backend:8080.

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: gateway
  name: gateway
spec:
  ports:
    - nodePort: 30500
      port: 80
      protocol: TCP
      targetPort: 8080
  selector:
    tier: gateway
  type: NodePort

Minikube, , NodePort. spec.ports.nodePort — . , 30000-32767.

Minikube

deploy.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: urls-config
data:
  BACKEND_URL: "http://backend:8080/"

---

apiVersion: v1
kind: Secret
metadata:
  name: msvc-secret
type: Opaque
stringData:
  secret: secret

---

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: backend
  name: backend
spec:
  ports:
    - port: 8080
      protocol: TCP
      targetPort: 8080
  selector:
    tier: backend

---

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: gateway
  name: gateway
spec:
  ports:
    - nodePort: 30500
      port: 80
      protocol: TCP
      targetPort: 8080
  selector:
    tier: gateway
  type: NodePort

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend
  labels:
    tier: backend
    app: microservices
spec:
  replicas: 3
  selector:
    matchLabels:
      tier: backend
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        tier: backend
    spec:
      containers:
        - name: backend
          image: anshelen/microservices-backend:latest
          envFrom:
            - configMapRef:
                name: urls-config
          ports:
            - containerPort: 8080
              protocol: TCP
          readinessProbe:
            httpGet:
              path: /actuator/health
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 3
          resources:
            limits:
              memory: "256Mi"
              cpu: "200m"
            requests:
              memory: "128Mi"
              cpu: "50m"

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway
  labels:
    tier: gateway
    app: microservices
spec:
  replicas: 3
  selector:
    matchLabels:
      tier: gateway
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        tier: gateway
    spec:
      containers:
        - name: gateway
          image: anshelen/microservices-gateway:latest
          envFrom:
            - configMapRef:
                name: urls-config
          env:
            - name: SECRET
              valueFrom:
                secretKeyRef:
                  name: msvc-secret
                  key: secret
          readinessProbe:
              httpGet:
                path: /actuator/health
                port: 8080
              initialDelaySeconds: 5
              periodSeconds: 3
          ports:
            - containerPort: 8080
              protocol: TCP
          resources:
            limits:
              memory: "256Mi"
              cpu: "200m"
            requests:
              memory: "128Mi"
              cpu: "50m"

kubectl apply -f deploy.yaml

Kubernetes URL :

minikube service gateway --url -n msvc-ns

for i in `seq 50`; do curl $(minikube service gateway --url -n msvc-ns) && echo; done

( ):

Number of requests 1 (gateway 544429797, secret secret)
Number of requests 1 (gateway 1543772618, secret secret)
Number of requests 2 (gateway 544429797, secret secret)
Number of requests 3 (gateway 544429797, secret secret)
Number of requests 4 (gateway 544429797, secret secret)
Number of requests 1 (gateway -1940767433, secret secret)
Number of requests 2 (gateway -1940767433, secret secret)
Number of requests 2 (gateway 1543772618, secret secret)
Number of requests 5 (gateway 544429797, secret secret)
...

Number of requests 1 (gateway 544429797, secret secret)
Number of requests 1 (gateway 1543772618, secret secret)
Number of requests 2 (gateway 544429797, secret secret)
Number of requests 3 (gateway 544429797, secret secret)
Number of requests 4 (gateway 544429797, secret secret)
Number of requests 1 (gateway -1940767433, secret secret)
Number of requests 2 (gateway -1940767433, secret secret)
Number of requests 2 (gateway 1543772618, secret secret)
Number of requests 5 (gateway 544429797, secret secret)
Number of requests 3 (gateway 1543772618, secret secret)
Number of requests 6 (gateway 544429797, secret secret)
Number of requests 3 (gateway -1940767433, secret secret)
Number of requests 4 (gateway 1543772618, secret secret)
Number of requests 7 (gateway 544429797, secret secret)
Number of requests 4 (gateway -1940767433, secret secret)
Number of requests 8 (gateway 544429797, secret secret)
Number of requests 9 (gateway 544429797, secret secret)
Number of requests 10 (gateway 544429797, secret secret)
Number of requests 5 (gateway 1543772618, secret secret)
Number of requests 5 (gateway -1940767433, secret secret)
Number of requests 6 (gateway -1940767433, secret secret)
Number of requests 7 (gateway -1940767433, secret secret)
Number of requests 6 (gateway 1543772618, secret secret)
Number of requests 8 (gateway -1940767433, secret secret)
Number of requests 7 (gateway 1543772618, secret secret)
Number of requests 11 (gateway 544429797, secret secret)
Number of requests 12 (gateway 544429797, secret secret)
Number of requests 8 (gateway 1543772618, secret secret)
Number of requests 9 (gateway -1940767433, secret secret)
Number of requests 10 (gateway -1940767433, secret secret)
Number of requests 11 (gateway -1940767433, secret secret)
Number of requests 9 (gateway 1543772618, secret secret)
Number of requests 10 (gateway 1543772618, secret secret)
Number of requests 11 (gateway 1543772618, secret secret)
Number of requests 12 (gateway -1940767433, secret secret)
Number of requests 12 (gateway 1543772618, secret secret)
Number of requests 13 (gateway 544429797, secret secret)
Number of requests 13 (gateway 1543772618, secret secret)
Number of requests 13 (gateway -1940767433, secret secret)
Number of requests 14 (gateway 1543772618, secret secret)
Number of requests 14 (gateway -1940767433, secret secret)
Number of requests 15 (gateway -1940767433, secret secret)
Number of requests 14 (gateway 544429797, secret secret)
Number of requests 15 (gateway 544429797, secret secret)
Number of requests 16 (gateway 544429797, secret secret)
Number of requests 17 (gateway 544429797, secret secret)
Number of requests 15 (gateway 1543772618, secret secret)
Number of requests 16 (gateway 1543772618, secret secret)
Number of requests 16 (gateway -1940767433, secret secret)
Number of requests 17 (gateway 1543772618, secret secret)

, . , , . - , -, , . , , . , 1 , 1000, "" , 1000 . , , , . .

kubectl get <object-type> — . 'pod', 'service', 'deployment' . 'all'.
kubectl get <object-type> <object-name> -o yaml — yaml-.
kubectl describe <object-type> <object-name> — .
kubectl cluster-info — .
kubectl top pod/node — /.

kubectl apply -f <file/directory> — .
kubectl delete <object-type> <object-name> — .
kubectl scale deployment <deployment-name> --replicas=n — . : n = 0, n, .
kubectl edit <object-type> <object-name> — .
kubectl rollout undo deployment <deployment-name> — .

kubectl logs <pod-name> — . -f .
kubectl port-forward <pod-name> <host-port>:<container-port> — . .
kubectl exec -it <pod-name> -- /bin/sh — .
kubectl run curl --image=radial/busyboxplus:curl -i --tty — . curl, , , .
kubectl get events --sort-by='.metadata.creationTimestamp' — Kubernetes. , , , .

GKE configuration

, , , Google Kubernetes Engine.

Services

GKE , IP-. , LoadBalancer:

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: gateway
  name: gateway
spec:
  selector:
    tier: gateway
  ports:
    - port: 80
      protocol: TCP
      targetPort: 8080
  type: LoadBalancer

, , . , GCP ( VPC -> IP-) , , spec.loadBalancerIp.

HorizontalPodAutoscalers

HorizontalPodAutoscaler . Minikube (- ), GKE .

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: backend
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: backend
  minReplicas: 1
  maxReplicas: 3
  targetCPUUtilizationPercentage: 50

spec.scaleTargetRef , backend. , 1 3 50%. , ( ), requests.cpu .

HorizontalPodAutoscaler' .

Quotas

. , (multitenant environment). , :

apiVersion: v1  
kind: ResourceQuota  
metadata:  
  name: msvc-quota  
spec:  
  hard:
    limits.cpu: "2"  
    limits.memory: 4Gi

- , . , , CLI (. kubectl run), LimitRange:

apiVersion: v1  
kind: LimitRange  
metadata:  
  name: msvc-default-resources  
spec:  
  limits: 
    - default:
        memory: "512Mi"  
        cpu: "250m"  
      defaultRequest:  
        memory: "256Mi"  
        cpu: "50m"  
      type: Container

, .

GKE

scripts_gke/.

create_quotas.yaml

apiVersion: v1  
kind: ResourceQuota  
metadata:  
  name: msvc-quota  
spec:  
  hard:
    limits.cpu: "2"  
    limits.memory: 4Gi

---  

apiVersion: v1  
kind: LimitRange  
metadata:  
  name: msvc-default-resources  
spec:  
  limits: 
    - default:
        memory: "512Mi"  
        cpu: "250m"  
      defaultRequest:  
        memory: "256Mi"  
        cpu: "50m"  
      type: Container

deploy.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: urls-config
data:
  BACKEND_URL: "http://backend:8080/"

---

apiVersion: v1
kind: Secret
metadata:
  name: msvc-secret
type: Opaque
stringData:
  secret: secret

---

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: backend
  name: backend
spec:
  ports:
    - port: 8080
      protocol: TCP
      targetPort: 8080
  selector:
    tier: backend

---

apiVersion: v1
kind: Service
metadata:
  labels:
    tier: gateway
  name: gateway
spec:
  selector:
    tier: gateway
  ports:
    - port: 80
      protocol: TCP
      targetPort: 8080
  type: LoadBalancer

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend
  labels:
    tier: backend
    app: microservices
spec:
  replicas: 2
  selector:
    matchLabels:
      tier: backend
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        tier: backend
    spec:
      containers:
        - name: backend
          image: anshelen/microservices-backend:latest
          envFrom:
            - configMapRef:
                name: urls-config
          ports:
            - containerPort: 8080
              protocol: TCP
          readinessProbe:
            httpGet:
              path: /actuator/health
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 3
          resources:
            limits:
              memory: "512Mi"
              cpu: "250m"
            requests:
              memory: "256Mi"
              cpu: "50m"

---

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: backend
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: backend
  minReplicas: 1
  maxReplicas: 3
  targetCPUUtilizationPercentage: 50

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway
  labels:
    tier: gateway
    app: microservices
spec:
  replicas: 2
  selector:
    matchLabels:
      tier: gateway
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        tier: gateway
    spec:
      containers:
        - name: gateway
          image: anshelen/microservices-gateway:latest
          envFrom:
            - configMapRef:
                name: urls-config
          env:
            - name: SECRET
              valueFrom:
                secretKeyRef:
                  name: msvc-secret
                  key: secret
          readinessProbe:
              httpGet:
                path: /actuator/health
                port: 8080
              initialDelaySeconds: 5
              periodSeconds: 3
          ports:
            - containerPort: 8080
              protocol: TCP
          resources:
            limits:
              memory: "512Mi"
              cpu: "250m"
            requests:
              memory: "256Mi"
              cpu: "50m"

---

apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: gateway
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: gateway
  minReplicas: 1
  maxReplicas: 3
  targetCPUUtilizationPercentage: 50

scripts_gke:

kubectl apply -f scripts_gke/

, . URL :

kubectl get svc gateway -o jsonpath='{.status.loadBalancer.ingress[0].ip}'

HorizontalPodAutoscaler' .

Kubernetes- Google Kubernetes Engine.

, , , . , … - , Kubernetes. ( ) Helm.

Dans la troisième partie de cette série d'articles, nous abordons Helm 3, créons un graphique de barre pour notre système et le mettons dans un référentiel créé sur la base des pages GitHub.

Apprendre à déployer des microservices. Partie 2. Kubernetes

Kubernetes

Kubernetes

Minikube configuration

Namespace:

ConfigMap

Secret

Deployments

Services

Minikube

GKE configuration

Services

HorizontalPodAutoscalers

Quotas

GKE

More articles: