Istio详细使用-灰度发布

蓝绿部署

所谓蓝绿部署是指在你的生产环境中同时有两套完全一致的应用，基于一套正在服务于线上环境，所有的请求都打到该环境中，当你的应用版本需要更新的时候，你直接在另外一套系统中部署新的版本，然后把流量切换到新的版本中。

蓝绿部署优缺点：

优点

你可以随意地去安装「备份的那一套环境」，而不需要动线上的环境，这样的话即使出错也没影响。同时因为有两套环境的存在，你也可以及时地进行回滚操作。
缺点

因为有两套环境的存在它的成本稍微有点高

灰度发布（金丝雀发布）

灰度发布（又名金丝雀发布）可以用来实现业务从老版本到新版本的平滑过渡，并避免升级过程中出现的问题对用户造成的影响。

金丝雀发布”的来源于矿工们用金丝雀对矿井进行空气测试的做法。以前矿工挖煤的时候，矿工下矿井前会先把金丝雀放进去，或者挖煤的时候一直带着金丝雀。金丝雀对甲烷和一氧化碳浓度比较敏感，会先报警。所以大家都用“金丝雀”来搞最先的测试。

下图中，左下方的少部分用户就被当作“金丝雀”来用于测试新上线的1.1版本。如果新版本出现问题，“金丝雀”们会报警，但不会影响其他用户业务的正常运行。

灰度发布（金丝雀发布）的流程如下：

准备和生产环境隔离的“金丝雀”服务器上。
将新版本的服务部署到“金丝雀”服务器上。
对“金丝雀”服务器上的服务进行自动化和人工测试。
测试通过后，将“金丝雀”服务器连接到生产环境，将少量生产流量导入到“金丝雀”服务器中。
如果在线测试出现问题，则通过把生产流量从“金丝雀”服务器中重新路由到老版本的服务的方式进行回退，修复问题后重新进行发布。
如果在线测试顺利，则逐渐把生产流量按一定策略逐渐导入到新版本服务器中。
待新版本服务稳定运行后，删除老版本服务。

Istio实现灰度发布(金丝雀发布)的操作步骤

1.环境安装

参考Istio官网使用 Helm 安装搭建Istio环境

2.部署V1、V2版本服务

# Copyright Istio 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.

##################################################################################################
# This file defines the services, service accounts, and deployments for the Bookinfo sample.
#
# To apply all 4 Bookinfo services, their corresponding service accounts, and deployments:
#
#   kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml
#
# Alternatively, you can deploy any resource separately:
#
#   kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml -l service=reviews # reviews Service
#   kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml -l account=reviews # reviews ServiceAccount
#   kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml -l app=reviews,version=v3 # reviews-v3 Deployment
##################################################################################################

##################################################################################################
# Details service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: details
  labels:
    app: details
    service: details
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: details
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-details
  labels:
    account: details
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: details-v1
  labels:
    app: details
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: details
      version: v1
  template:
    metadata:
      labels:
        app: details
        version: v1
    spec:
      serviceAccountName: bookinfo-details
      containers:
      - name: details
        image: docker.io/istio/examples-bookinfo-details-v1:1.18.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Ratings service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: ratings
  labels:
    app: ratings
    service: ratings
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: ratings
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-ratings
  labels:
    account: ratings
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ratings-v1
  labels:
    app: ratings
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ratings
      version: v1
  template:
    metadata:
      labels:
        app: ratings
        version: v1
    spec:
      serviceAccountName: bookinfo-ratings
      containers:
      - name: ratings
        image: docker.io/istio/examples-bookinfo-ratings-v1:1.18.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Reviews service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: reviews
  labels:
    app: reviews
    service: reviews
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: reviews
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-reviews
  labels:
    account: reviews
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v1
  labels:
    app: reviews
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v1
  template:
    metadata:
      labels:
        app: reviews
        version: v1
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v1:1.18.0
        imagePullPolicy: IfNotPresent
        env:
        - name: LOG_DIR
          value: "/tmp/logs"
        ports:
        - containerPort: 9080
        volumeMounts:
        - name: tmp
          mountPath: /tmp
        - name: wlp-output
          mountPath: /opt/ibm/wlp/output
      volumes:
      - name: wlp-output
        emptyDir: {}
      - name: tmp
        emptyDir: {}
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v2
  labels:
    app: reviews
    version: v2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v2
  template:
    metadata:
      labels:
        app: reviews
        version: v2
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v2:1.18.0
        imagePullPolicy: IfNotPresent
        env:
        - name: LOG_DIR
          value: "/tmp/logs"
        ports:
        - containerPort: 9080
        volumeMounts:
        - name: tmp
          mountPath: /tmp
        - name: wlp-output
          mountPath: /opt/ibm/wlp/output
      volumes:
      - name: wlp-output
        emptyDir: {}
      - name: tmp
        emptyDir: {}
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v3
  labels:
    app: reviews
    version: v3
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v3
  template:
    metadata:
      labels:
        app: reviews
        version: v3
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v3:1.18.0
        imagePullPolicy: IfNotPresent
        env:
        - name: LOG_DIR
          value: "/tmp/logs"
        ports:
        - containerPort: 9080
        volumeMounts:
        - name: tmp
          mountPath: /tmp
        - name: wlp-output
          mountPath: /opt/ibm/wlp/output
      volumes:
      - name: wlp-output
        emptyDir: {}
      - name: tmp
        emptyDir: {}
---
##################################################################################################
# Productpage services
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: productpage
  labels:
    app: productpage
    service: productpage
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: productpage
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-productpage
  labels:
    account: productpage
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: productpage-v1
  labels:
    app: productpage
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: productpage
      version: v1
  template:
    metadata:
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "9080"
        prometheus.io/path: "/metrics"
      labels:
        app: productpage
        version: v1
    spec:
      serviceAccountName: bookinfo-productpage
      containers:
      - name: productpage
        image: docker.io/istio/examples-bookinfo-productpage-v1:1.18.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
        volumeMounts:
        - name: tmp
          mountPath: /tmp
      volumes:
      - name: tmp
        emptyDir: {}
---

3.配置virtual-service和网关服务

apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: bookinfo-gateway
spec:
  # The selector matches the ingress gateway pod labels.
  # If you installed Istio using Helm following the standard documentation, this would be "istio=ingress"
  selector:
    istio: ingress # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: bookinfo
spec:
  hosts:
  - "*"
  gateways:
  - bookinfo-gateway
  http:
  - match:
    - uri:
        exact: /productpage
    - uri:
        prefix: /static
    - uri:
        exact: /login
    - uri:
        exact: /logout
    - uri:
        prefix: /api/v1/products
    route:
    - destination:
        host: productpage
        port:
          number: 9080
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: productpage
spec:
  hosts:
  - productpage
  http:
  - route:
    - destination:
        host: productpage
        subset: v1
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v1
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - route:
    - destination:
        host: ratings
        subset: v1
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: details
spec:
  hosts:
  - details
  http:
  - route:
    - destination:
        host: details
        subset: v1
---

4.配置destination-rule服务

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: productpage
spec:
  host: productpage
  subsets:
  - name: v1
    labels:
      version: v1
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: ratings
spec:
  host: ratings
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v2-mysql
    labels:
      version: v2-mysql
  - name: v2-mysql-vm
    labels:
      version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: details
spec:
  host: details
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
---

此时系统中部署了V1和V2两个版本的reviews服务，但所有的业务流量都被规则reviews-default导向了V1，如下图所示：

多次刷新访问页面如下：

5.将测试流量导入到V2版本的reviews服务

在进行模拟测试时，由于测试环境和生产环境的网络，服务器，操作系统等环境存在差异，很难完全模拟生产环境进行测试。为了减少环境因素的对测试结果的影响，我们希望能在生产环境中进行上线前的测试，但如果没有很好的隔离措施，可能会导致测试影响已上线的业务，对企业造成损失。

通过采用Istio的路由规则，可以在类生产环境中进行测试，又完全隔离了线上用户的生产流量和测试流量，最小化模拟测试对已上线业务的影响。如下图所示：

创建一条规则，将用户名为 test-user 的流量导入到V2

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - match:
    - headers:
        end-user:
          exact: test-user 
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1

结果如下：

6.将部分生产流量导入到V2版本的reviews服务

在线上模拟测试完成后，如果系统测试情况良好，可以通过规则将一部分用户流量导入到V2版本的服务中，进行小规模的“金丝雀”测试。

修改规则将50%的流量导入V2版本

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1
      weight: 50
    - destination:
        host: reviews
        subset: v2
      weight: 50

7.将所有生产流量导入到到V2版本的reviews服务

如果新版本的服务运行正常，则可以将所有流量导入到V2版本。

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v2
      weight: 100