Alfred Sabitzer - K8s Applications mit MicroK8S auf Raspberry PI

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alfred@monitoring:~/GetInfo$ ll *.tar

-rw-rw-r-- 1 alfred alfred 326244864 Oct 15 21:27 getinfo.tar

alfred@monitoring:~/GetInfo$

Wir können aber auch das Dockerfile selbst exportieren.

alfred@monitoring:~/GetInfo$ docker ps -all

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

acdf3516a1ce docker.registry:5000/getinfo:20211015 "/GetInfo" 10 minutes ago Exited (2) 5 minutes ago funny_keller

alfred@monitoring:~/GetInfo$ docker export acdf3516a1ce > getinfo.tar

alfred@monitoring:~/GetInfo$

alfred@monitoring:~/GetInfo$ ll -h *.tar

-rw-rw-r-- 1 alfred alfred 311M Oct 15 21:32 getinfo.tar

alfred@monitoring:~/GetInfo$

alfred@monitoring:~/GetInfo$ tar -tvf getinfo.tar

Mit diesen Befehlen kann man überprüfen was alles im Container drinnenn ist (und das ist eine ganze Menge).

Nun pushen wir den Container in das remote-Repository. Es werden natürlich alle Layer gepushed (in dem Falle gab es die darunterliegenden Layer noch nicht).

alfred@monitoring:~/GetInfo$ docker push docker.registry:5000/getinfo:20211015

The push refers to repository [docker.registry:5000/getinfo]

cae68116d3ec: Pushed

dd68a1e5bd54: Pushed

00e2dc9bf745: Pushed

5a8d0b1f55c0: Pushed

8f352be1ccfe: Pushed

729e17fedb70: Pushed

08ae3e8fdb37: Pushed

6fe1ba639418: Pushed

fa0d2ce7179e: Pushed

092886e29cb5: Pushed

c8d42fc353a6: Pushed

6a91c97933c9: Pushed

ee420dfed78a: Pushed

20211015: digest: sha256:aa82ba777936d4cec354c0b9c5ece353751a96c9717375cfd58d3ed2beea5cf4 size: 3030

alfred@monitoring:~/GetInfo$

Kurze Kontrolle, ob der Container wirklich im Remote Repository gelandet ist.

alfred@monitoring:~/GetInfo$ curl docker.registry:5000/v2/_catalog

{"repositories":["getinfo","hello-world"]}

alfred@monitoring:~/GetInfo$ curl docker.registry:5000/v2/getinfo/tags/list

{"name":"getinfo","tags":["20211015"]}

alfred@monitoring:~/GetInfo$

Abbildung 22: Longhorn Plattengröße

Auch in der Longhorn-Anzeige kann man schön sehen, dass dieses Volume nicht mehr leer ist, und jetzt bereits ca. 1GB Platz braucht.

Nun erzeugen wir ein yaml-File.

---

apiVersion: apps/v1

kind: Deployment

metadata:

name: getinfo

#namespace: default

spec:

selector:

matchLabels:

app: getinfo

replicas: 1

template:

metadata:

labels:

app: getinfo

annotations:

sidecar.istio.io/inject: "false"

spec:

containers:

- name: getinfo

image: docker.registry:5000/getinfo:20211015

# resource limits

resources:

requests:

memory: "24Mi"

cpu: "500m" # half vcpu

limits:

memory: "64Mi"

cpu: "1000m" # one vcpu

env:

# currently no env vars used for this container

- name: FOO

value: bar

# check for lifetime liveness, restarts if dead

livenessProbe:

exec:

command:

- ls

initialDelaySeconds: 5

periodSeconds: 10

# check for initial readyness

readinessProbe:

exec:

command:

- ls

initialDelaySeconds: 3

periodSeconds: 3

# pod bekommt diesselbe Zeitzone wie der darunterliegende Node

volumeMounts:

- name: tz-local

mountPath: /etc/localtime

volumes:

- name: tz-local

hostPath: # abhängig vom darunterliegenden OS. Das hier ist linux.

path: /etc/localtime

restartPolicy: Always

dnsPolicy: ClusterFirst

---

apiVersion: v1

kind: Service

metadata:

name: getinfo-service

#namespace: default

labels:

app: getinfo

spec:

ports:

# port=available to other containers

- port: 8080

name: hello

# targetPort=exposed from inside container

targetPort: 8080

protocol: TCP

selector:

app: getinfo

---

Dieses yaml wenden wir nun im Cluster an.

alfred@pc1:~$ k apply -f getinfo.yaml

deployment.apps/getinfo created

service/getinfo-service created

alfred@pc1:~$ kubectl get all

NAME READY STATUS RESTARTS AGE

pod/webserver-slainte-67494d5d7b-hj99r 1/1 Running 22 67d

pod/getinfo-6c84cff999-mtf5v 1/1 Running 0 89s

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE

service/kubernetes ClusterIP 10.152.183.1 443/TCP 67d

service/webserver-slainte ClusterIP 10.152.183.125 443/TCP 67d