czezz's questions

POD nginx-pod executa o servidor HTTP escutando na porta 9000. SERVICE nginx-svc (ClusterIP) para ele é criado. Arquivos Yaml na parte inferior da postagem.

kubectl get po -ntest -o wide
NAME         READY   STATUS    RESTARTS   AGE   IP              NODE            NOMINATED NODE   READINESS GATES
nginx-curl   1/1     Running   0          57s   172.16.158.37   worker-node02   <none>           <none>
nginx-pod    1/1     Running   0          17m   172.16.87.229   worker-node01   <none>           <none>

kubectl -ntest get svc
NAME        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
nginx-svc   ClusterIP   172.17.22.178   <none>        9000/TCP   11s

Problema/Pergunta: Quando eu "enrolo" DE: pod nginx-curl PARA: nginx-pod IP 172.16.87.229 (aquele com nginx escutando na porta 9000), funciona:

 $ kubectl -ntest exec -it nginx-curl -- bash
 root@nginx-curl:/# curl  172.16.87.229:9000
 Works!

Quando eu "curl" FROM: pod nginx-curl TO: nginx-svc IP 172.17.22.178 não funciona:

$ kubectl -ntest exec -it nginx-curl -- bash
root@nginx-curl:/# curl 172.17.22.178:9000
curl: (7) Failed to connect to 172.17.22.178 port 9000: Connection refused

O que estou fazendo de errado? Por que o nginx-svc é inútil?

Meus arquivos YAML usados ​​para este teste: nginx-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  namespace: test
  labels:
    app: aaa
spec:
  containers:
    - name: nginx-container
      image: nginx:1.16
      command: ["/bin/sh","-c"]
      args: ["sed -i 's/listen  .*/listen 9000;/g' /etc/nginx/conf.d/default.conf && exec nginx -g 'daemon off;'"]
      ports:
        - containerPort: 9000
          name: "http-server"

nginx-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
  namespace: test
  labels:
    app: aaa
spec:
  type: ClusterIP
  selector:
    app: aaa
    name: nginx-pod
  ports:
    - port: 9000
      targetPort: 9000

Criei PV, PVC e adicionei esse PVC ao POD.

Problema/Pergunta: Ao adicionar PVC (no meu entendimento) é como anexar armazenamento externo/adicional. No entanto, quando me conecto ao POD, não vejo nenhum sistema de arquivos adicional. Por que?

kubectl exec -it pod1 -- bash
root@pod1:/# df -Th
Filesystem                        Type     Size  Used Avail Use% Mounted on
overlay                           overlay   31G  5.9G   23G  21% /
tmpfs                             tmpfs     64M     0   64M   0% /dev
shm                               tmpfs     64M     0   64M   0% /dev/shm
tmpfs                             tmpfs    197M  2.0M  195M   2% /etc/hostname
/dev/mapper/ubuntu--vg-ubuntu--lv ext4      31G  5.9G   23G  21% /etc/hosts
tmpfs                             tmpfs    1.9G   12K  1.9G   1% /run/secrets/kubernetes.io/serviceaccount
tmpfs                             tmpfs    983M     0  983M   0% /proc/acpi
tmpfs                             tmpfs    983M     0  983M   0% /proc/scsi
tmpfs                             tmpfs    983M     0  983M   0% /sys/firmware

Passos para reproduzir:

$ kubectl apply -f pv1.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv1
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  claimRef:
    namespace: default
    name: pvc1-volume
  hostPath:
    path: "/opt/storage"

kubectl get pv -o wide
NAME    CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                  STORAGECLASS   REASON   AGE   VOLUMEMODE
pv1     1Gi        RWO            Retain           Available   default/pvc1-volume    manual                  4s    Filesystem

$ kubectl apply -f  pvc1.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc1-volume
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Mi

$ kubectl apply -f pvc1.yaml
persistentvolumeclaim/pvc1-volume created

$ kubectl get pvc -o wide
NAME           STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE   VOLUMEMODE
pvc1-volume    Bound    pv1      1Gi        RWO            manual         8s    Filesystem

kubectl apply -f pod1.yaml
apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  volumes:
    - name: task-pv-storage
      persistentVolumeClaim:
        claimName: pvc1-volume
  containers:
    - name: nginx
      image: nginx:1.16
      ports:
        - containerPort: 80
          name: "http-server"
      volumeMounts:
        - mountPath: "/usr/share/nginx/html"
          name: task-pv-storage

kubectl get po
NAME          READY   STATUS    RESTARTS   AGE
pod1          1/1     Running   0          28s