应用的蓝绿、金丝雀发布笔记
应用升级策略
Deployment.spec.strategy设置Recreate：同时删除所有副本，停机升级策略
不存在新老版本共存
存在某个时间段服务不可用
副本集一起Terminating，一起Pending，一起ContainerCreating，一起Running
RollingUpdate：默认滚动升级，不停机升级策略
- 不存在某个时间段服务不可用
- 切换过程,新老版本会共存
- 滚动更新核心参数
- maxUnavailable：滚动升级时允许的最大unavailable的pod数量，可以是整数或者百分比（默认25%）,这个值越小，越能保证服务稳定，更新越平滑；
- maxSurge：滚动升级时先启动的pod数量，可以是整数或者百分比（默认25%），这个值调的越大，副本更新速度越快；
停机升级
示例
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
selector:
app: nginx-v1
ports:
- protocol: TCP
port: 80
targetPort: 80
nodePort: 30179
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v1
namespace: default
labels:
app: nginx-v1
spec:
selector:
matchLabels:
app: nginx-v1
replicas: 3
strategy:
type: Recreate ## 需要显式指明停机升级策略，因为默认是滚动升级
template:
metadata:
labels:
app: nginx-v1
spec:
containers:
- name: nginx-v1
image: docker.m.daocloud.io/nginx:1.23.1
imagePullPolicy: IfNotPresent
接下来我们修改一下镜像版本，进行停机更新升级
image: docker.m.daocloud.io/nginx
滚动更新
默认就是滚动更新策略
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
selector:
app: nginx-v1
ports:
- protocol: TCP
port: 80
targetPort: 80
nodePort: 30179
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v1
namespace: default
labels:
app: nginx-v1
spec:
selector:
matchLabels:
app: nginx-v1
replicas: 3
# strategy:
# type: Recreate ## 需要显式指明停机升级策略，因为默认是滚动升级
template:
metadata:
labels:
app: nginx-v1
spec:
containers:
- name: nginx-v1
image: docker.m.daocloud.io/nginx:1.23.1
imagePullPolicy: IfNotPresent
- 可以通过更改以下字段，来变更每次被嘎的数量和启动新的版本的数量
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 25% ###最大被嘎的数量，越小，更新越平滑
maxSurge: 25% ### 启动新的pod数量，越大，副本更新越快
- 滚动更新：会有新旧版本同时存在的问题
蓝绿发布
发布原理
- svc的selector选择器
- v1版本和v2版本同时启动，然后通过修改svc一键切换
- 无缝升级，无缝回退，不存在两个版本共存的现象
- 生产环境推荐，只不过会增加资源开销
v1版本
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v1
namespace: default
labels:
app: nginx-v1
spec:
selector:
matchLabels:
app: nginx-v1
replicas: 3
template:
metadata:
labels:
app: nginx-v1
spec:
containers:
- name: nginx-v1
image: docker.m.daocloud.io/nginx:1.23.1
imagePullPolicy: IfNotPresent
v2版本
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v2
namespace: default
labels:
app: nginx-v2
spec:
selector:
matchLabels:
app: nginx-v2
replicas: 3
template:
metadata:
labels:
app: nginx-v2
spec:
containers:
- name: nginx-v2
image: docker.m.daocloud.io/nginx
imagePullPolicy: IfNotPresent
svc
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
selector:
app: nginx-v1
ports:
- protocol: TCP
port: 80
targetPort: 80
nodePort: 30179
type: NodePort
当前访问情况
修改svc的selector信息为v2然后观察
spec:
selector:
app: nginx-v2
while true;do curl -sI 192.168.1.225:30179 | grep -E 'Server|HTTP';done
金丝雀发布
金丝雀发布就是先发一个新版应用，但是是一个小比例范围，也叫灰度测试，如结果灰度测试通过，就把其余的v1版本全部替换程v2版本。如果测试没通过，就直接回退
- 新功能验证，适当的引流，适合金丝雀发布
v1
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v1
namespace: default
labels:
app: nginx-v1
spec:
selector:
matchLabels:
app: nginx
replicas: 3
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: docker.m.daocloud.io/nginx:1.23.1
imagePullPolicy: IfNotPresent
v2
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-v2
namespace: default
labels:
app: nginx-v2
spec:
selector:
matchLabels:
app: nginx
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: docker.m.daocloud.io/nginx
imagePullPolicy: IfNotPresent
svc
---
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
selector:
app: nginx
ports:
- protocol: TCP
port: 80
targetPort: 80
nodePort: 30179
type: NodePort
灰度测试成功，我们逐渐将流量切入过去即可
### 修改副本数即可
