add sexy-tips.md

SUMMARY.md

@@ -43,6 +43,7 @@
 - [Docker 中文指南](https://github.com/widuu/chinese_docker/blob/master/SUMMARY.md)
 - [Docker 官方文档](https://docs.docker.com/reference/)
 - [阿里k8s 项目实战手册](k8s&container/ali-kubernetes.pdf)
+- [k8s 奇淫巧计](k8s&container/sexy-tips.md)
 - [k8s 数据持久化](k8s&container/storage-examples.md)
 - [k8s 技术文档](k8s&container/k8s-map.pdf)
 - [云原生介绍](k8s&container/cloud-native.pdf)

k8s&container/sexy-tips.md

@@ -0,0 +1,184 @@
+# k8s 使用的一些技巧
+
+
+
+## 在容器中获取pod 的IP
+
+设置一个环境变量来引用 resource 的状态字段：
+
+```yaml
+kind: StatefulSet
+apiVersion: apps/v1
+metadata:
+  name: redis-app
+  namespace: ops
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      containers:
+        - name: redis
+          image: 'redis:5.0'
+          command:
+            - redis-server
+          args:
+            - /etc/redis/redis.conf
+            - '--protected-mode'
+            - 'no'
+            - '--cluster-announce-ip'
+            - $(POD_IP)
+          ports:
+            - name: redis
+              containerPort: 6379
+              protocol: TCP
+          env:
+            - name: POD_IP
+              valueFrom:
+                fieldRef:
+                  apiVersion: v1
+                  fieldPath: status.podIP
+
+```
+
+
+
+## pod 使用外部DNS
+
+修改 `coredns` 的使用的 `ConfigMap`
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: coredns
+  namespace: kube-system
+data:
+  Corefile: |
+    .:53 {
+        errors
+        health {
+          lameduck 5s
+        }
+        hosts {
+          10.8.30.157  test-master
+          10.8.30.152  test-n1
+          10.8.30.156  test-n2
+          10.8.30.155  test-n3
+          10.8.30.161  test-n4
+          10.8.30.141  test-n5
+          10.8.30.35   node35
+          10.8.30.36   node36
+          10.8.30.37   node37
+          10.8.30.38   node38
+          fallthrough
+        }
+        ready
+        kubernetes cluster.local in-addr.arpa ip6.arpa {
+          pods insecure
+          fallthrough  in-addr.arpa ip6.arpa
+          ttl 30
+        }
+        prometheus :9153
+        # upstreamNameservers
+        forward . 114.114.114.114 223.5.5.5 {
+          max_concurrent 1000
+        }
+        cache 30
+        loop
+        reload
+        loadbalance
+    }
+    # stubDomains
+    k8s.com:53 {
+      errors
+      cache 30
+      forward . 192.168.10.10
+    } 
+      
+```
+
+## 创建一个Ubuntu测试容器
+
+
+
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: test
+  labels:
+    app: test
+spec:
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: test
+    spec:
+      containers:
+      - image: ubuntu:20.04
+        name: test
+        command: ["/bin/bash","-c","while true; do sleep 1000; done"]
+        imagePullPolicy: IfNotPresent
+```
+
+
+
+## 强制删除某 pod
+
+
+
+```shell
+kubectl delete pod <pod>  [-n <namespace>] --force --grace-period=0
+```
+
+
+
+## 使容器内时间与宿主机同步
+
+我们下载的很多容器内的时区都是格林尼治时间，与北京时间差8小时，这将导致容器内的日志和文件创建时间与实际时区不符，有两种方式解决这个问题：
+
+- 修改镜像中的时区配置文件
+- 将宿主机的时区配置文件`/etc/localtime`使用volume方式挂载到容器中
+
+第二种方式比较简单，无需重新制作镜像：
+
+```yaml
+apiVersion: apps/v1 # for versions before 1.8.0 use apps/v1beta1
+kind: Deployment
+metadata:
+  name: test
+  namespace: test
+  labels:
+    app: test
+spec:
+  selector:
+    matchLabels:
+      app: test
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: test
+    spec:
+      containers:
+      - name: test
+        image: ubuntu:20.04
+        volumeMounts:
+        - name: localtime
+          mountPath: /etc/localtime
+      volumes:
+      - name: localtime
+        hostPath:
+          path: /etc/localtime
+
+```
+
+
+