- ubuntu系统,macOS更好,windows玩的溜也行.
摘要
kubernates功能繁杂,刚接触之人,即使勉力窥得全貌,但实际应用中,用不到一成.借助rancher,不但省去数日苦修的功夫,又可直接使用k8s常用成熟的功能.简单了解下k8s的基础架构和基本命令,即可上手.
配置rancher-cli
1. 下载\配置\登录
- 下载链接
- Linux下配置环境变量可以任意目录下执行rancher命令
- 在rancher网页版控制台创建token,使用rancher loginde 命令登录
rancher login https://xx.xx.xx.xx/v3 --token xxxxxxxxxx
2. 集群监控命令
- 切换命名空间
jia@jia:~$ rancher context switch
NUMBER CLUSTER NAME PROJECT ID PROJECT NAME PROJECT DESCRIPTION
1 xqkj-kubernetes c-6mxlt:p-d5h6f 系统空间 System project created for the cluster
2 xqkj-kubernetes c-6mxlt:p-qr9kv zy
3 xqkj-kubernetes c-6mxlt:p-xgcdx 默认空间 Default project created for the cluster
4 xqkj-kubernetes-pro c-xmqxg:p-62jtx System System project created for the cluster
5 xqkj-kubernetes-pro c-xmqxg:p-m8tjm Default Default project created for the cluster
Select a Project:3
INFO[0008] Setting new context to project 默认空间
INFO[0008] Saving config to /home/jia/.rancher/cli2.json
- 查看集群状态
jia@jia:~$ rancher kubectl cluster-info
Kubernetes master is running at https://47.102.41.70/k8s/clusters/c-6mxlt
metrics-server is running at https://47.102.41.70/k8s/clusters/c-6mxlt/api/v1/namespaces/kube-system/services/heapster/proxy
KubeDNS is running at https://47.102.41.70/k8s/clusters/c-6mxlt/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
- 查看node状态
jia@jia:~$ rancher kubectl top nodes
NAME CPU(cores) CPU% MEMORY(bytes) MEMORY%
cn-shanghai.i-uf62lelgjwuyiwuxfp6j 121m 6% 5163Mi 75%
cn-shanghai.i-uf68nqijeqfoc81wkqvb 160m 8% 5923Mi 86%
cn-shanghai.i-uf68nqijeqfoc81wkqvc 141m 7% 4379Mi 64%
- 查看pod状态
jia@jia:~$ rancher kubectl top pods
NAME CPU(cores) MEMORY(bytes)
apollo-admin-694b45b7bc-86sm9 3m 383Mi
apollo-config-7496bf6d7f-xq5fr 6m 455Mi
bell-5489bcdc56-qfgrg 8m 766Mi
confucius-697c5c5fd5-fhj4b 14m 1049Mi
kotler-59c7cd7c48-fqw9s 13m 745Mi
platon-95c5c8cfc-dh2zl 9m 1054Mi
socrates-546bcd7f5b-5vbhp 11m 944Mi
zipkin-db66577bc-k44sx 4m 254Mi
- 查看pod详情
jia@jia:~$ rancher kubectl describe pod apollo-admin-694b45b7bc-86sm9
Name: apollo-admin-694b45b7bc-86sm9
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: cn-shanghai.i-uf68nqijeqfoc81wkqvb/172.19.100.137
Start Time: Mon, 22 Apr 2019 13:34:34 +0800
Labels: pod-template-hash=694b45b7bc
workload.user.cattle.io/workloadselector=deployment-default-apollo-admin
Annotations: cattle.io/timestamp: 2019-04-22T05:34:34Z
field.cattle.io/ports:
[[{"containerPort":8090,"dnsName":"apollo-admin-loadbalancer","kind":"LoadBalancer","name":"8090tcp80873","protocol":"TCP","sourcePort":80...
Status: Running
IP: 10.0.1.185
Controlled By: ReplicaSet/apollo-admin-694b45b7bc
Containers:
apollo-admin:
Container ID: docker://d8b9bcf44b6df9a713e3f23ac756d3cd73e6ed091744f3c9d8aae964d9dcaafe
Image: registry-vpc.cn-shanghai.aliyuncs.com/quanwai_base/base:apollo-adminserviceV1
Image ID: docker-pullable://registry-vpc.cn-shanghai.aliyuncs.com/quanwai_base/base@sha256:d6ba0ee2152fac329eaf34442f533cd45e55ec3004a7fcb1bd67aaaee786ce3d
...............
3. 部署常用命令
所有部署命令都必须指定资源描述文件deployment
- kubectl apply -f
若资源不存在则创建,存在则更新
jia@jia:~/IdeaProjects/kotler$ rancher kubectl apply -f deployment.yaml
configmap/filebeat-kotler unchanged
deployment.apps/kotler configured
使用rancher控制台管理k8s集群
只要明确以下几点,即可利用rancher控制台简单管理k8s集群
-
镜像仓库
公用仓库是默认的,私有仓库需要配置,如不配置,则无法下载自己的镜像.私有仓库配置如下图:
image -
容器开放端口
一般容器都需要开放端口,让外部访问,按照k8s容器端口访问规则,rancher提供以下几种选项:
image -
容器挂载卷
- 挂载配置卷
-
声明配置卷
image -
挂载配置卷
image
-
- 挂载存储卷
- 存储卷就是要存储文件的,所有集群下的容器均可访问,好像是分布式文件存储的感觉.在解决神策打点数据采集的问题时,就是通过NAS存储方案解决的.
- 首先要在阿里云上申请NAS存储服务,再利用rancher在集群上创建PV.最后在命令空间下创建PVC.PV就是持久卷-集群共享,所有得在集群上创建,PVC是在命名空间下声明的PV属性(读写权限,大小等).
- 挂载配置卷
创建PV
创建PV
创建PVC
创建PVC
使用卷
使用卷
3. 容器共享卷
共享卷是同一个pod下,多个容器共享同一个目录,在使用filebeat采集服务容器日志的时候,就需要filebeat容器共享服务容器的日志目录.(同一个pod下服务容器作为主容器,日志收集容器叫做伴随容器).
在主容器创建空目录卷,同样的在伴随容器也创建,两者的挂载目录要一致.
创建空目录卷
- 容器健康检查
服务要提供心跳检测接口,以便k8s检查容器心跳,判断容器状态,及时调度容器.
rancher上配置如下:
image
有几个地方需要注意一下.给服务留下充足的初始化时间,心跳检测不宜太频繁,时间间隔大概30秒即可.超时时间设置为3~5秒.
livenessProbe: # 存活探针检查
failureThreshold: 3 # 默认失败次数
httpGet:
path: /promotion/heartbeat
port: 8081
scheme: HTTP
initialDelaySeconds: 60
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 3
readinessProbe: # 就绪状态检查
failureThreshold: 3
httpGet:
path: /promotion/heartbeat
port: 8081
scheme: HTTP
initialDelaySeconds: 60
periodSeconds: 5
successThreshold: 2
timeoutSeconds: 3
-
注入主机环境变量
环境变量主要作为服务启动时区分正式测试环境配置的钥匙.无论以何种形式引用环境变量,最终都是一个key-value形式的Linux环境变量.
image
- env: # 注入环境变量
- name: APOLLO_META
value: http://139.224.169.234:8086
- name: env
value: dev
- name: ZK_ADDRESS
valueFrom:
configMapKeyRef:
name: configmap
key: ZK_ADDRESS
- 资源限定
资源限定包括两项,启动时请求的资源和运行时最高可利用资源.资源是指CPU和memory.
image
resources:
limits:
cpu: 200m
memory: 256Mi
requests:
cpu: 20m
memory: 128Mi
kubernates的deployment文件
#定义日志收集相关配置的一个configmap
apiVersion: v1
kind: ConfigMap # 声明这个资源的类型
metadata:
name: filebeat-kotler # 声明配置的名称
namespace: default # 声明命令空间
data: # data属性下是具体配置内容,配置内容直接元模原样copy出来就行.
filebeat.yml: |
filebeat.prospectors:
- input_type: log
paths:
- "/data/applogs/kotler/kotler.log"
fields:
project: kotler-test
multiline:
pattern: ^\d{4}
negate: true
match: after
max_lines: 1000
timeout: 10s
output.logstash:
hosts: ["172.19.1.12:5044"]
---
apiVersion: apps/v1beta2
kind: Deployment # 声明资源类型
metadata: # 声明资源的元数据包括标签和注解(给选择器选择,方便调度),都是ke-value形式
annotations:
deployment.kubernetes.io/revision: "4"
field.cattle.io/creatorId: u-nbbnv
field.cattle.io/publicEndpoints: '[{"port":8093,"protocol":"TCP","serviceName":"default:kotler-loadbalancer","allNodes":false}]'
labels:
cattle.io/creator: norman
workload.user.cattle.io/workloadselector: deployment-default-kotler
name: kotler
namespace: default
spec: # 控制器的规描述
progressDeadlineSeconds: 600
replicas: 1 # 启动几个容器
revisionHistoryLimit: 10
selector: # 选择器
matchLabels:
workload.user.cattle.io/workloadselector: deployment-default-kotler
strategy: # 升级策略
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
type: RollingUpdate
template: # 模板,创建和升级容器的模板
metadata:
annotations:
cattle.io/timestamp: 2019-03-15T08:52:38Z
field.cattle.io/ports: '[[{"containerPort":8081,"dnsName":"kotler-loadbalancer","kind":"LoadBalancer","name":"8081tcp80913","protocol":"TCP","sourcePort":8093}]]'
labels:
workload.user.cattle.io/workloadselector: deployment-default-kotler
spec: # 容器具体的描述
containers:
- env: # 注入环境变量
- name: APOLLO_META
value: http://139.224.169.234:8086
- name: env
value: dev
- name: ZK_ADDRESS
valueFrom:
configMapKeyRef:
name: configmap
key: ZK_ADDRESS
image: registry-vpc.cn-shanghai.aliyuncs.com/quanwai_pre/pre:kotlerV37
imagePullPolicy: Always # 镜像拉去策略
livenessProbe: # 存活探针
failureThreshold: 3 # 默认失败次数
httpGet:
path: /promotion/heartbeat
port: 8081
scheme: HTTP
initialDelaySeconds: 60
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 3
name: kotler
volumeMounts: # 绑定的卷
- name: applogs
mountPath: /data/applogs/kotler
- name: kotler-pv
mountPath: /data/appdatas/sa
- name: cat
mountPath: /data/appdatas/cat
ports: # 端口声明
- containerPort: 8081
name: 8081tcp80913
protocol: TCP
readinessProbe: # 就绪状态检查
failureThreshold: 3
httpGet:
path: /promotion/heartbeat
port: 8081
scheme: HTTP
initialDelaySeconds: 60
periodSeconds: 5
successThreshold: 2
timeoutSeconds: 3
resources:
limits:
cpu: 200m
memory: 256Mi
requests:
cpu: 20m
memory: 128Mi
- image: registry-vpc.cn-shanghai.aliyuncs.com/quanwai_base/base:filebeat # 伴随容器的配置,和主容器类似
imagePullPolicy: Always
name: filebeat
args: [
"-c", "/etc/filebeat/filebeat.yml",
"-e",
]
volumeMounts:
- name: applogs
mountPath: /data/applogs/kotler
- name: filebeat
mountPath: /etc/filebeat
volumes: # pod声明的卷
- name: applogs
emptyDir: {}
- name: filebeat
configMap:
name: filebeat-kotler
- name: cat
configMap:
name: cat-config
- name: kotler-pv # pvc
persistentVolumeClaim:
claimName: nas-for-kubernetes
dnsPolicy: ClusterFirst
restartPolicy: Always # pod的失败重启策略
后记
k8s的sidecar(日志收集方案),启动一个名叫filebeat的伴随容器,共享主容器的日志目录,收集主容器的日志,上报到logstash.每个主容器都有对应的伴随容器.
基于阿里云NAS的存储方案,云存储方案的选择是有坑的,第一次选用的是OSS,结果是多容器读写同一个文件会产写数据丢失的情况,也就是说并不是所有存储方案都能适用所有的数据读写场景.初步看来,OSS方案,很方便向共享空间上传文件,
,适合读的场景,NAS方案更适合对文件写频繁的情况下.
