1. 概述

默认istio的limist是：

　　cpu: 2000m 
　　memory: 1024Mi

request也是很大，部署用例一多，很浪费资源，所以就想修改istio的默认配置

2. 生成当前的manifest文件

istioctl manifest generate > generated-manifest.yaml

这个文件很大，有1w多行，我就不贴出来了，这个是istio的部署文件。

3. 修改manifest文件

这里8850行修改limits/request的cpu/memory：

"proxy": {
          "autoInject": "enabled",
          "clusterDomain": "cluster.local",
          "componentLogLevel": "misc:error",
          "enableCoreDump": false,
          "excludeIPRanges": "",
          "excludeInboundPorts": "",
          "excludeOutboundPorts": "",
          "holdApplicationUntilProxyStarts": false,
          "image": "proxyv2",
          "includeIPRanges": "*",
          "includeInboundPorts": "*",
          "includeOutboundPorts": "",
          "logLevel": "warning",
          "privileged": false,
          "readinessFailureThreshold": 30,
          "readinessInitialDelaySeconds": 1,
          "readinessPeriodSeconds": 2,
          "resources": {
            "limits": {
              "cpu": "100m",
              "memory": "200Mi"
            },
            "requests": {
              "cpu": "10m",
              "memory": "50Mi"
            }
          },
          "statusPort": 15020,
          "tracer": "zipkin"
        },
        "proxy_init": {
          "image": "proxyv2",
          "resources": {
            "limits": {
              "cpu": "100m",
              "memory": "200Mi"
            },
            "requests": {
              "cpu": "10m",
              "memory": "10Mi"
            }
          }
        },

还有10287行这里修改limits/request的cpu/memory：

 readinessProbe:
            failureThreshold: 30
            httpGet:
              path: /healthz/ready
              port: 15021
              scheme: HTTP
            initialDelaySeconds: 1
            periodSeconds: 2
            successThreshold: 1
            timeoutSeconds: 1
          resources:
            limits:
              cpu: 100m
              memory: 200Mi
            requests:
              cpu: 10m
              memory: 50Mi

4. 根据manifest文件重新安装istio

卸载：

istioctl uninstall —purge

如果没有装过istio,先要执行以下命令：

sudo kubectl create namespace istio-system 

sudo istioctl manifest generate --set values.defaultRevision=default

通过kubectl安装istio：

kubectl apply -f generated-manifest.yaml

验证安装：

istioctl verify-install -f generated-manifest.yaml

修改以后看下其他pod是否limit正常：

sudo kubectl describe nodes

可以看到limitrange都正常了。