python application deploy with minikube

Docker image 생성 및 deployment 생성

아래와 같이 Dockerfile을 생성하고 Build하여 image로 생성한다.

jacob@jacob-laptop:~/workspaces/hellopy$ cat Dockerfile 
FROM python:3.7.4
EXPOSE 8000
CMD python -m SimpleHTTPServer
jacob@jacob-laptop:~/workspaces/hellopy$ docker build -t hello-py:v1 .
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM python:3.7.4
 ---> 02d2bb146b3b
Step 2/3 : EXPOSE 8000
 ---> Using cache
 ---> b72c3a572cbd
Step 3/3 : CMD python -m SimpleHTTPServer
 ---> Using cache
 ---> 8ed128fb4a3e
Successfully built 8ed128fb4a3e
Successfully tagged hello-py:v1

생성된 Docker image를 사용하영 kubectl로 deployment를 생성한다.

jacob@jacob-laptop:~/workspaces/hellopy$ kubectl run hello-py --image=hello-py:v1 --port=8000 --image-pull-policy=Never
kubectl run --generator=deployment/apps.v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create instead.
deployment.apps/hello-py created

실제 생성된 pod를 확인한다.

jacob@jacob-laptop:~/workspaces/hellopy$ kubectl get pods --context=minikube
NAME                                READY   STATUS             RESTARTS   AGE
hello-py-5844b45b8b-thcth           0/1     CrashLoopBackOff   8          18m
nginx-deployment-54f57cf6bf-hhwlv   1/1     Running            0          32m
nginx-deployment-54f57cf6bf-v94k8   1/1     Running            0          32m

CrashLoopBackOff 현상확인

확인시 pod에 CrashLoopBackOff문제가 있음을 확인할 수 있다. 이를 좀더 명확히 확인하고자 log를 확인한다.

jacob@jacob-laptop:~/workspaces/hellopy$ kubectl logs hello-py-5844b45b8b-thcth
/usr/local/bin/python: No module named SimpleHTTPServer

application 문제해결 및 deployment 업데이트

확인된 로그상에서 SimpleHTTPServer Module을 찾을수 없음을 말하고 있다.

python 3.X대 부터는 SimpleHTTPServer module 대신 http.server를 사용할 수 있다.

Dockerfile을 수정하여 다시 deployment를 생성해보자.

jacob@jacob-laptop:~/workspaces/hellopy$ cat Dockerfile 
FROM python:3.7.4
EXPOSE 8000
CMD python3 -m http.server
jacob@jacob-laptop:~/workspaces/hellopy$ docker build -t hello-py:v2 .
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM python:3.7.4
 ---> 02d2bb146b3b
Step 2/3 : EXPOSE 8000
 ---> Using cache
 ---> b72c3a572cbd
Step 3/3 : CMD python3 -m http.server
 ---> Running in 4cacb174f630
Removing intermediate container 4cacb174f630
 ---> 4ac44ef8d878
Successfully built 4ac44ef8d878
Successfully tagged hello-py:v2

다시 build된 이미지를 기존 deployment내 image에 업데이트 한다.

jacob@jacob-laptop:~/workspaces/hellopy$ kubectl set image deployment/hello-py hello-py=hello-py:v2
deployment.apps/hello-py image updated

이후 다시 pod를 확인해보면 다음과 같이 다시 정상 deploy되었음을 확인할 수 있다.

jacob@jacob-laptop:~/workspaces/hellopy$ kubectl get pods
NAME                                READY   STATUS        RESTARTS   AGE
hello-py-5844b45b8b-thcth           0/1     Terminating   11         32m
hello-py-7bb87fd7bf-4vcck           1/1     Running       0          8s
nginx-deployment-54f57cf6bf-hhwlv   1/1     Running       0          46m
nginx-deployment-54f57cf6bf-v94k8   1/1     Running       0          46m
jacob@jacob-laptop:~/workspaces/hellopy$ kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
hello-py-7bb87fd7bf-4vcck           1/1     Running   0          12s
nginx-deployment-54f57cf6bf-hhwlv   1/1     Running   0          46m
nginx-deployment-54f57cf6bf-v94k8   1/1     Running   0          46m

마지막으로 minikube를 통해 웹접속을 수행해보자.

jacob@jacob-laptop:~/workspaces/hellopy$ minikube service hello-py
|-----------|----------|-------------|-----------------------------|
| NAMESPACE |   NAME   | TARGET PORT |             URL             |
|-----------|----------|-------------|-----------------------------|
| default   | hello-py |             | http://192.168.99.102:30234 |
|-----------|----------|-------------|-----------------------------|
🎉  Opening kubernetes service  default/hello-py in default browser...

browser가 출력되고 정상적으로 웹접속이 이루어짐을 확인할 수 있다.

참고사이트

https://medium.com/humanscape-tech/kubernetes-%EB%8F%84%EC%9E%85-%EC%A0%84-minikube-%EC%82%AC%EC%9A%A9%EA%B8%B0-2eb2b6d8e444