[k8s]一些技巧性的yaml和dockerfile-docker学习思路
我会把一些dockerfile和yaml的技巧性东西不定期搜集到这里docker学习思路
三部曲:
[*]1,vm会搭建服务
[*]2,docker会跑服务
[*]3,k8s集群会调度该服务
存储
[*]vm1 vm2 共享存储,vm1的容器挂了直接调度到vm2(docker存储驱动实现)
网络
[*]物理机安装flannel,使两台docker上容器能通(物理机/容器搭建etcd集群)
[*]物理机搭建openvswitch,实现两台docker
监控
[*]cadvisor会跑
[*]物理机安装grafana,物理机安装promethus(实现nodeexplore和mysqlexplore)
[*]容器跑promethus +cadvisor+grafana
[*]容器跑cadvisor+influendb+grafana
[*]容器跑elk,物理机跑filebeat搜集容器日志
pod的一些技巧
参考: https://jimmysong.io/kubernetes-handbook/appendix/tricks.html
[*]在容器中获取 Pod 的IP
[*]指定容器的启动参数
[*]让Pod调用宿主机的docker能力
[*]使用Init container初始化应用配置
[*]使容器内时间与宿主机同步
[*]在Pod中获取宿主机的主机名、namespace等
[*]配置Pod使用外部DNS
dockerfile
tomcat 启动
EXPOSE 8080
CMD ["catalina.sh", "run"]
nginx日志和启动
# forward request and error logs to docker log collector
RUN ln -sf /dev/stdout /var/log/nginx/access.log \
&& ln -sf /dev/stderr /var/log/nginx/error.log
EXPOSE 80
STOPSIGNAL SIGTERM
CMD ["nginx", "-g", "daemon off;"]
yaml 让busybox当计数器
apiVersion: v1
kind: Pod
metadata:
name: counter
spec:
containers:
- name: count
image: busybox
args:
相当于
docker run -d --name=b1 busyboxi=0; while true; do echo "$i: $(date)"; i=$((i+1)); sleep 1; done
docker run -d \ --log-driver=fluentd \
--log-opt fluentd-address=localhost:24224 \
--log-opt tag="log-test-container-A" \
busybox sh -c 'while true; do echo "This is a log message from container A"; sleep 10; done;'
yaml 让busybox执行一个脚本
参考: https://kubernetes.io/docs/concepts/cluster-administration/logging/
apiVersion: v1
kind: Pod
metadata:
name: counter
spec:
containers:
- name: count
image: busybox
args:
- /bin/sh
- -c
- >
i=0;
while true;
do
echo "$i: $(date)" >> /var/log/1.log;
echo "$(date) INFO $i" >> /var/log/2.log;
i=$((i+1));
sleep 1;
done
volumeMounts:
- name: varlog
mountPath: /var/log
- name: count-log-1
image: busybox
args:
volumeMounts:
- name: varlog
mountPath: /var/log
- name: count-log-2
image: busybox
args:
volumeMounts:
- name: varlog
mountPath: /var/log
volumes:
- name: varlog
emptyDir: {}
yaml 让busybox睡5min
参考: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/#dns-policy
apiVersion: v1
kind: Pod
metadata:
name: busybox
namespace: default
spec:
containers:
- image: busybox
command:
- sleep
- "3600"
imagePullPolicy: IfNotPresent
name: busybox
restartPolicy: Always
dockerfile拷贝目录的一个坑
参考: https://stackoverflow.com/questions/26504846/copy-directory-to-other-directory-at-docker-using-add-command
## 拷贝文件不需要写目标
FROM centos
COPY 2.txt /usr/local/
## 拷贝目录则需要这样写,目标,不然拷贝不进去
FROM centos
COPY mysql /usr/local/mysql
设置容器的TZ另一种办法
## override default time zone (Etc/UTC) if TZ variable is set
if [ ! -z "$TZ" ]; then
ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
fi
k8s集群里pod高负载访问apiserver的8080(api对外地址)
因为api对内地址是443
集群api如果有3台,则需要负载访问,咋办呢? 自定义svc,endpoint,实现对外负载(如果只有一个apiserver,则直连即可)
kind: Endpoints
apiVersion: v1
metadata:
name: kube-apiserver-http
namespace: kube-public
subsets:
- addresses:
- ip: 192.168.x.132
- ip: 192.168.x.133
- ip: 192.168.x.134
ports:
- name: http
port: 8080
protocol: TCP
kind: Service
apiVersion: v1
metadata:
labels:
app-name: kube-apiserver-http
name: kube-apiserver-http
namespace: kube-public
spec:
ports:
- name: http
port: 80
targetPort: 8080
protocol: TCP
sessionAffinity: ClientIP
command写法和容器privileged模式设置(cni部署网络)/容器获取宿主机(外界/或集群ns的名字)参数
参考: https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml
https://feisky.gitbooks.io/kubernetes/network/flannel/#cni集成
http://cizixs.com/2017/05/23/container-network-cni
command: [ "/opt/bin/flanneld", "--ip-masq", "--kube-subnet-mgr" ] securityContext:
privileged: true
env: - name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
参考
env: - name: MY_POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: MY_POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: MY_POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
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