Alfred Sabitzer - K8s Applications mit MicroK8S auf Raspberry PI

Removing intermediate container 03fd6b04a839

---> e62606c61d94

Step 7/8 : EXPOSE 80

---> Running in 2b3562abb146

Removing intermediate container 2b3562abb146

---> 121727752180

Step 8/8 : CMD ["hallo"]

---> Running in cfa9e78598dc

Removing intermediate container cfa9e78598dc

---> 52dfdc427a61

Successfully built 52dfdc427a61

Successfully tagged docker.registry:5000/hello-world:20211003

alfred@monitoring:~/dev/hello-world$

Anzeige im lokalen Repository.

alfred@monitoring:~/go$ docker images

REPOSITORY TAG IMAGE ID CREATED SIZE

docker.registry:5000/hello-world 20211003 ebe5a2422dca 24 seconds ago 2.1MB

alfred@monitoring:~/go$

Wir können den Inhalt untersuchen, indem wir den Docker in ein Tar-File exportieren.

alfred@monitoring:~/go$ docker ps -lq

fc63f4826cff

alfred@monitoring:~/go$

alfred@monitoring:~/go$ mkdir test

alfred@monitoring:~/go$ docker export fc63f4826cff > ./test/hello-world.tar

alfred@monitoring:~/go$ cd test/

alfred@monitoring:~/go/test$ tar -xf hello-world.tar

alfred@monitoring:~/go/test$ ll

total 4132

drwxrwxr-x 6 alfred alfred 4096 Oct 3 09:37 ./

drwxrwxr-x 4 alfred alfred 4096 Oct 3 09:37 ../

-rwxr-xr-x 1 alfred alfred 0 Oct 3 09:32 .dockerenv*

drwxr-xr-x 4 alfred alfred 4096 Oct 3 09:32 dev/

drwxr-xr-x 2 alfred alfred 4096 Oct 3 09:32 etc/

-rwxrwxr-x 1 alfred alfred 2097605 Sep 30 11:26 hello-world*

-rw-rw-r-- 1 alfred alfred 2105344 Oct 3 09:37 hello-world.tar

drwxr-xr-x 2 alfred alfred 4096 Oct 3 09:32 proc/

drwxr-xr-x 2 alfred alfred 4096 Oct 3 09:32 sys/

alfred@monitoring:~/go/test$

Wir können das Image auch lokal starten.

alfred@monitoring:~/dev/hello-world$ docker run docker.registry:5000/hello-world:20211003

hello world

alfred@monitoring:~/dev/hello-world$

Pushen in das remote-Repository. In dem Falle gibt es einen darunter liegenden den Layer schon.

alfred@monitoring:~/dev/hello-world$ docker push docker.registry:5000/hello-world:20211003

The push refers to repository [docker.registry:5000/hello-world]

6fa65fc3457a: Pushed

af86841dfdf3: Pushed

001055a1bdf7: Pushed

350991c52258: Pushed

93bd567aa306: Pushed

b48145e02449: Pushed

20211003: digest: sha256:cf16e57415939719367e5e17c09d2f17e36af2c1b84f24208f5750ea2c18b485 size: 1570

alfred@monitoring:~/dev/hello-world$

Anzeige aller vorhandenen Images im Remote Repository

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

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

alfred@monitoring:~/go$

alfred@monitoring:~/go$ curl docker.registry:5000/v2/hello-world/tags/list

{"name":"hello-world","tags":["20211003","20211001","20210830","20210930"]}

alfred@monitoring:~/go$

alfred@monitoring:~/go$ curl docker.registry:5000/v2/hello-world/manifests/20211003

{

"schemaVersion": 1,

"name": "hello-world",

"tag": "20211003",

"architecture": "arm64",

"fsLayers": [

{

"blobSum": "sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4"

},

{

"blobSum": "sha256:34b32ef7cc99133a34d56a284820986ce50c2ff9c1864da8557458489d7428a1"

}

],

"history": [

{

"v1Compatibility": "{\"architecture\":\"arm64\",\"config\":{\"Hostname\":\"\",\"Domainname\":\"\",\"User\":\"\",\"AttachStdin\":false,\"AttachStdout\":false,\"AttachStderr\":false,\"Tty\":false,\"OpenStdin\":false,\"StdinOnce\":false,\"Env\":[\"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin\"],\"Cmd\":[\"/hello-world\"],\"Image\":\"sha256:c7642e609037b051e03214a85ddc50434de042a6b08c23bcac16dcb92629ee46\",\"Volumes\":null,\"WorkingDir\":\"\",\"Entrypoint\":null,\"OnBuild\":null,\"Labels\":null},\"container\":\"6d8917fc20a0fcbece354d49781ee260e15cb02df65c35efa5978f583948f9c4\",\"container_config\":{\"Hostname\":\"6d8917fc20a0\",\"Domainname\":\"\",\"User\":\"\",\"AttachStdin\":false,\"AttachStdout\":false,\"AttachStderr\":false,\"Tty\":false,\"OpenStdin\":false,\"StdinOnce\":false,\"Env\":[\"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin\"],\"Cmd\":[\"/bin/sh\",\"-c\",\"#(nop) \",\"CMD [\\\"/hello-world\\\"]\"],\"Image\":\"sha256:c7642e609037b051e03214a85ddc50434de042a6b08c23bcac16dcb92629ee46\",\"Volumes\":null,\"WorkingDir\":\"\",\"Entrypoint\":null,\"OnBuild\":null,\"Labels\":{}},\"created\":\"2021-10-03T07:40:42.472956387Z\",\"docker_version\":\"20.10.7\",\"id\":\"031921ba69921f2705920021974bfdc500b6f42530f679aa56481bdbf1543d3e\",\"os\":\"linux\",\"parent\":\"91fdfdcec09b0c57e4f28bd9c1d199796b66e5162c2e0432f8a9dc689952e13c\",\"throwaway\":true,\"variant\":\"v8\"}"

},

{

"v1Compatibility": "{\"id\":\"91fdfdcec09b0c57e4f28bd9c1d199796b66e5162c2e0432f8a9dc689952e13c\",\"created\":\"2021-10-03T07:40:35.230309736Z\",\"container_config\":{\"Cmd\":[\"/bin/sh -c #(nop) COPY file:c46bbf237d2238c6f6241fa3c853f5d4861e4981bd19d09a99fa3f1ef76ed73a in / \"]}}"

}

],

"signatures": [

{

"header": {

"jwk": {

"crv": "P-256",

"kid": "AADV:MDEU:C5BD:UTIA:ME3T:42HB:WJUA:GTV4:DHU6:KPQM:OXBY:RRAS",

"kty": "EC",

"x": "PEw45Fk1zyjGc6iHHYh6_Ydk3mxLC8UE1mvlo_6XY24",

"y": "8e-Ad67SUvJMaYHjlyh05hqv7kcekIm6J-jR8It9unA"

},

"alg": "ES256"

},

"signature": "0iZv8OxENn9Oo_2eTyIQpfxFgBBsIW1z4p0AfkxP-bBxDE-1i5SN76FTwsLdTI9SRHnyY6R0_AoMSB1gWacdeA",

"protected": "eyJmb3JtYXRMZW5ndGgiOjIxMjUsImZvcm1hdFRhaWwiOiJDbjAiLCJ0aW1lIjoiMjAyMS0xMC0wM1QwODoxNjoxM1oifQ"

}

]

alfred@monitoring:~/go$

Somit ist das Image im Repository. Jetzt brauchen wir noch eine Service Definition.

alfred@pc1:/opt/cluster/go$ cat hello-world.yaml

---

apiVersion: apps/v1

kind: Deployment

metadata:

name: hello-world

#namespace: default

spec:

selector:

matchLabels:

app: hello-world

replicas: 1

template:

metadata:

labels:

app: hello-world

annotations:

sidecar.istio.io/inject: "false"

spec:

containers:

- name: hello-world

image: docker.registry:5000/hello-world:20211003

# 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:

- /hello-world

initialDelaySeconds: 5

periodSeconds: 10

# check for initial readyness

readinessProbe:

exec:

command:

- /hello-world

initialDelaySeconds: 3

periodSeconds: 3

restartPolicy: Always

dnsPolicy: ClusterFirst

---

apiVersion: v1

kind: Service

metadata:

name: hello-world-service

#namespace: default

labels:

app: hello-world

spec:

ports:

# port=available to other containers

- port: 1234

name: hello

# targetPort=exposed from inside container

targetPort: 1234

protocol: TCP

selector:

app: hello-world

---

alfred@pc1:/opt/cluster/go$

Nun installieren wir den Service.

alfred@pc1:/opt/cluster/go$ kubectl apply -f hello-world.yaml

deployment.apps/hello-world created

service/hello-world-service created

alfred@pc1:/opt/cluster/go$

Wir kontrollieren ob der Service richtig gestartet wird.

alfred@pc1:/opt/cluster/go$ kubectl describe -n default pod hello-world-6bb7844865-4j5bw

Name: hello-world-6bb7844865-4j5bw

Namespace: default

Priority: 0

Node: pc5/192.168.0.205

Start Time: Sun, 03 Oct 2021 20:56:03 +0200