[5] MicroK8s – Magazyny

Aby włączyć wbudowane w MicroK8s magazyny skonfiguruj go tak jak poniżej.
[1] Włącz wbudowany magazyn na pierwszym/głównym węźle

[root@vlsr01 ~]# export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/lib64"
[root@vlsr01 ~]# microk8s enable storage
Enabling default storage class
deployment.apps/hostpath-provisioner created
storageclass.storage.k8s.io/microk8s-hostpath created
serviceaccount/microk8s-hostpath created
clusterrole.rbac.authorization.k8s.io/microk8s-hostpath created
clusterrolebinding.rbac.authorization.k8s.io/microk8s-hostpath created
Storage will be available soon

# uruchomiony zostaje pods [hostpath-provisioner]
[root@vlsr01 ~]# microk8s kubectl -n kube-system get pods
NAME READY STATUS RESTARTS AGE
calico-node-vq9h7 1/1 Running 0 2d1h
metrics-server-8bbfb4bdb-x2rrq 1/1 Running 2 2d2h
calico-kube-controllers-847c8c99d-mv2g6 1/1 Running 2 2d3h
calico-node-574jj 1/1 Running 2 2d3h
kubernetes-dashboard-7ffd448895-fq852 1/1 Running 0 6h57m
dashboard-metrics-scraper-6c4568dc68-mh6jd 1/1 Running 0 6h57m
hostpath-provisioner-5c65fbdb4f-5qm5d 1/1 Running 0 6h57m
coredns-86f78bb79c-kptf4 1/1 Running 0 6h57m

[2] W tym przykładzie użyjemy magazynu do zdefiniowania obiektu PVC (Persistent Volume Claim)

[root@vlsr01 ~]# mcedit zl-pvc.yml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
# dowolna nazwa
name: zl-pvc
spec:
# tryby dostępu:
# - ReadWriteMany (RW z wielu węzłów)
# - ReadWriteOnce (RW z węzła)
# - ReadOnlyMany (R z wielu węzłów)
accessModes:
- ReadWriteMany
# sprecyzuj microk8s-hostpath
storageClassName: microk8s-hostpath
resources:
requests:
# rozmiar magazynu do użycia
storage: 1Gi

[root@vlsr01 ~]# microk8s kubectl create -f zl-pvc.yml
persistentvolumeclaim/zl-pvc created

[root@vlsr01 ~]# microk8s kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-e5ee45b5-83e0-4c6d-a2c1-688357e58aaf 1Gi RWX Delete Bound default/zl-pvc microk8s-hostpath 8s

[root@vlsr01 ~]# microk8s kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
zl-pvc Bound pvc-e5ee45b5-83e0-4c6d-a2c1-688357e58aaf 1Gi RWX microk8s-hostpath 26s

# dla przykładu stwórzmy kapsułę nginx
# UWAGA NA WCIĘCIA!!!
[root@vlsr01 ~]# mcedit nginx-zl.yml
apiVersion: v1
kind: Pod
metadata:
name: nginx-zl
labels:
name: nginx-zl
spec:
containers:
- name: nginx-zl
image: fedora/nginx
ports:
- name: web
containerPort: 80
volumeMounts:
- name: zl-persistent-volume
mountPath: /usr/share/nginx/html
volumes:
- name: zl-persistent-volume
persistentVolumeClaim:
# wpisz nazwę utworzonego wcześniej PVC
claimName: zl-pvc

[root@vlsr01 ~]# microk8s kubectl create -f nginx-zl.yml
pod/nginx-zl created
[root@vlsr01 ~]# microk8s kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-zl 1/1 Running 0 81s 10.1.86.210 vlsr01.zicher.lab <none> <none>

# potwierdź ścieżkę PVC
[root@vlsr01 ~]# microk8s kubectl describe -n kube-system pod/hostpath-provisioner-5c65fbdb4f-5qm5d | grep PV_DIR
PV_DIR: /var/snap/microk8s/common/default-storage
[root@vlsr01 ~]# microk8s kubectl describe pvc/zl-pvc | grep ^Volume:
Volume: pvc-e5ee45b5-83e0-4c6d-a2c1-688357e58aaf

# stwórz testową stronę
[root@vlsr01 ~]# echo "MicroK8s - ZICHER.LAB" > /var/snap/microk8s/common/default-storage/default-zl-pvc-pvc-e5ee45b5-83e0-4c6d-a2c1-688357e58aaf/index.html

# sprawdź czy to działa
[root@vlsr01 ~]# curl 10.1.86.210
MicroK8s - ZICHER.LAB