1、编写源代码及Dockerfile
test.py
from flask import Flask
import socket
app = Flask(__name__)
@app.route('/')
def hello():
return socket.gethostbyname(socket.gethostname())
if __name__ == '__main__':
app.run(host='0.0.0.0', port=5001)
requirements.txt
flask
Docfile
FROM python:3.8-slim-buster
# 设置工作目录
WORKDIR /app
# 将当前目录下的所有文件复制到容器的工作目录
COPY . /app
# 安装 Flask 和其他依赖项
RUN pip install -r requirements.txt
# 指定端口号
EXPOSE 5001
# 在容器启动时运行命令
CMD ["python", "/app/test.py"]
2、打包镜像：docker build -t liu/test .
3、登录阿里云仓库：docker login --username=用户名 registry.cn-hangzhou.aliyuncs.com，输入密码
4、docker images查看镜像ID，给镜像打tag：docker tag 镜像ID registry.cn-hangzhou.aliyuncs.com/csugis/我的仓库:版本号
5、推送到远程仓库：docker push registry.cn-hangzhou.aliyuncs.com/csugis/我的仓库:版本号
6、编写部署文件test01.yaml
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: flask-web-app
labels:
app: flask-web-app
version: v1
spec:
replicas: 3
selector:
matchLabels:
app: flask-web-app
version: v1
template:
metadata:
labels:
app: flask-web-app
version: v1
spec:
containers:
- name: flask-web-app
image: registry.cn-hangzhou.aliyuncs.com/csugis/我的仓库:版本号
ports:
- containerPort: 5001
---
apiVersion: v1
kind: Service
metadata:
name: flask-web-app-service
spec:
type: NodePort
ports:
- port: 5001
protocol: TCP
targetPort: 5001
nodePort: 32510
name: http
selector:
app: flask-web-app
version: v1
7、在部署机上执行：kubectl apply -f test01.yaml
[root@node app]# kubectl apply -f test01.yaml
deployment.apps/flask-web-app created
service/flask-web-app-service created
8、查看部署情况：
[root@k8s-master01 ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
flask-web-app-service NodePort 10.68.51.169 <none> 5001:32510/TCP 10s
kubernetes ClusterIP 10.68.0.1 <none> 443/TCP 9d
9[root@k8s-master01 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
flask-web-app-59d498b4c4-8p6kj 1/1 Running 0 32s 172.20.5.27 192.168.209.135 <none> <none>
flask-web-app-59d498b4c4-s2bbb 1/1 Running 0 32s 172.20.4.35 192.168.209.134 <none> <none>
flask-web-app-59d498b4c4-vsgw8 1/1 Running 0 32s 172.20.3.19 192.168.209.133 <none> <none>
9、测试
[root@k8s-master01 ~]# curl 10.68.51.169:5001
172.20.5.27
[root@k8s-master01 ~]# curl 10.68.51.169:5001
172.20.4.35
[root@k8s-master01 ~]# curl 10.68.51.169:5001
172.20.3.19
开始试了一天，出现一个问题：服务只在一个节点上有响应，请求另外两个节点上的pod服务均返回
curl: (7) Failed connect to 172.20.4.34:5001; Connection refused这样的报错
经过kubectl logs flask-web-app-58fd7f9888-brmj6查看日志
[root@k8s-master01 ~]# kubectl logs flask-web-app-58fd7f9888-brmj6
* Serving Flask app 'test'
* Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
* Running on http://127.0.0.1:5001
Press CTRL+C to quit
[root@k8s-master01 ~]# kubectl logs flask-web-app-58fd7f9888-6s9c6
* Serving Flask app 'test'
* Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
* Running on all addresses (0.0.0.0)
* Running on http://127.0.0.1:5001
* Running on http://172.20.3.18:5001
Press CTRL+C to quit
kubectl exec -it flask-web-app-58fd7f9888-brmj6 -n default bash进入容器排查
[root@k8s-master01 ~]# kubectl exec -it flask-web-app-58fd7f9888-brmj6 -n default bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
root@flask-web-app-58fd7f9888-brmj6:/app# ls
test.py
root@flask-web-app-58fd7f9888-brmj6:/app# cat test.py
from flask import Flask
import socket
app = Flask(__name__)
@app.route('/')
def hello():
return socket.gethostbyname(socket.gethostname())
if __name__ == '__main__':
app.run(port=5001)
发现问题出在镜像的版本上。可以正确返回的那个节点上的代码是最新正确版，另外两个是之前的版本(没写port=0.0.0.0)，但是他们都是同一个版本号v1，导致不同机器上的代码不一致。然后重新打tag上传镜像，并重新部署才得到正确的返回
删除deployment：kubectl delete deployment flask-web-app
删除svc：kubectl delete svc flask-web-app-service