K0s kasutamine

Sissejuhatus

TODO

Tööpõhimõte

TODO

Paigaldamine

Järgnevas kirjeldatakse k0s süsteemi paigaldamise variatsioone.

Paigaldamine - vanilla

Väited

• süsteem töötab ilma k0s seadistuseta
• ei ole paigaldatud pv jaoks vajalikku storage class lahendust paigaldamise osana
• ei ole paigaldatud ingress controller'it paigaldamise osana

https://docs.k0sproject.io/v1.27.5+k0s.0/install/, kõige lihtsamal juhtumil paigadamine ja käivitamine

# curl -sSLf https://get.k0s.sh | sudo sh
Downloading k0s from URL: https://github.com/k0sproject/k0s/releases/download/v1.27.5+k0s.0/k0s-v1.27.5+k0s.0-amd64
k0s is now executable in /usr/local/bin

# k0s install controller --single
# k0s start
# k0s status
# k0s kubectl get nodes

k0s protsesside lõpetamine ja süsteemist eemaldamine

# k0s stop
# k0s reset
# reboot

Paigaldamine - vanilla + openebs

Väited

• paigaldust juhitakse k0s seadistusfailiga
• paigaldamise käigus tekib lisaks 'Paigaldamine - vanilla' olukorrale openebs storage lahendus
• https://docs.k0sproject.io/v1.27.5+k0s.0/storage/ (navigeerida 'Usage -> Storage (CSI)')

esmalt moodustatakse k0s seadistusfail

# mkdir /etc/k0s
# k0s config create > /etc/k0s/k0s.yaml

ning kasutatakse k0s.yaml failis muu hulgas sektsiooni (need direktiivid ei esine tõenäoliselt litrally järjest, aga on spreitud sobivalt)

spec:
  extensions:
    storage:
      type: openebs_local_storage

k0s süsteemi käivitamine toimub üldiselt samamoodi nagu vanilla juhtumil, kuid install tuleb teha koos -c suvandiga

# k0s install controller --single -c /etc/k0s/k0s.yaml

Oodatav tulemus on, et süsteemis on olemas openebs storage class

# k0s kubectl get storageclass
NAME               PROVISIONER        RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
openebs-device     openebs.io/local   Delete          WaitForFirstConsumer   false                  6d2h
openebs-hostpath   openebs.io/local   Delete          WaitForFirstConsumer   false                  6d2h

Storage class saab kasutada nt sellise nginx yaml abil

apiVersion: v1
kind: Namespace
metadata:
  name: web

---
apiVersion: v1
kind: Service
metadata:
  name: web-server-service
  namespace: web
spec:
  selector:
    app: web
  ports:
    - protocol: TCP
      port: 5000
      targetPort: 80

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nginx-pvc
  namespace: web
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: openebs-hostpath
  resources:
    requests:
      storage: 512Mi

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: web
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx 
        name: nginx
        volumeMounts:
        - name: persistent-storage
          mountPath: /var/lib/nginx
      volumes:
      - name: persistent-storage
        persistentVolumeClaim:
          claimName: nginx-pvc

Deployimiseks sobib öelda

# kubectl apply -f create-pvc.yaml

Tulemusena tekib deployment, eriti kasutatakse pv/pvc ressursse (pv ei ole namespace põhine ressurss)

# k0s kubectl get pvc -n web
NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS       AGE
nginx-pvc   Bound    pvc-4bba23d7-eeb6-4485-b1df-b2b4c6657665   512Mi      RWO            openebs-hostpath   58s

# k0s kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM           STORAGECLASS       REASON   AGE
pvc-4bba23d7-eeb6-4485-b1df-b2b4c6657665   512Mi      RWO            Delete           Bound    web/nginx-pvc   openebs-hostpath            49s

Kustutamiseks sobib öelda

# kubectl delete -f create-pvc.yaml

Paigaldamine - vanilla + metallb

Väited

• https://docs.k0sproject.io/v1.27.5+k0s.0/examples/metallb-loadbalancer/
• iga service on ligipääsetav isikliku ip aadressiga (mis võimaldab service juures kasutada personaalset sertifikaati)
• service saab pakkuda teenust suvalisel pordil (st ei ole nö ingress kontrolleri 80/443/http/tcp vms piirangut)

Paigaldamiseks sobib kasutada custom k0s seadistusfailis lisaks sektsiooni

spec:
  extensions:
    helm:
      repositories:
      - name: metallb
        url: https://metallb.github.io/metallb
      charts:
      - name: metallb
        chartname: metallb/metallb
        namespace: metallb

ning paigaldada k0s nö tavalisel viisil custom seadistust arvestades. Seejärel moodustada IPAddressPool ja L2Advertisement tüüpi ressursid, kasutada sobivat ip vahemikku

---
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: first-pool
  namespace: metallb-system
spec:
  addresses:
  - 192.168.10.120-192.168.10.124

---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: example
  namespace: metallb-system

Tulemusena on olemas vastavad ressursid

# k0s kubectl get IPAddressPool -n metallb
NAME         AGE
first-pool   9m51s

# k0s kubectl get  L2Advertisement -n metallb
NAME      AGE
example   9m54s

MetalLB võimalusi kasutava service paigaldamiseks sobib kasutada sellist manifesti

# cat create-metallb-base-service.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: web
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-server
  namespace: web
spec:
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
      - name: httpd
        image: httpd:2.4.53-alpine
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: web-server-service
  namespace: web
spec:
  selector:
    app: web
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: LoadBalancer

ning öelda

# k0s kubectl apply -f create-metallb-base-service.yaml

Tulemusena saab brauserist pöörduda aadressile http://192.168.10.120/ (konkreetne ip valitakse pool sees nii nagu ta parasjagu valitakse), küsida saab nii

# k0s kubectl get service -n web
NAME                 TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)        AGE
web-server-service   LoadBalancer   10.106.230.54   192.168.10.120   80:32482/TCP   6s

Paigaldamine - nginx ingress kontroller + nodeport

Väited

• https://docs.k0sproject.io/v1.27.5+k0s.0/examples/nginx-ingress/ - 'Install NGINX using NodePort'

Lahenduse paigaldamiseks sobib öelda

# k0s kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/baremetal/deploy.yaml
# k0s kubectl get pods -n ingress-nginx
NAME                                        READY   STATUS      RESTARTS   AGE
ingress-nginx-admission-create-pmsdz        0/1     Completed   0          12m
ingress-nginx-admission-patch-7g225         0/1     Completed   0          12m
ingress-nginx-controller-5d45d7c8c4-rrntc   1/1     Running     0          12m

# k0s kubectl get services -n ingress-nginx
NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
ingress-nginx-controller             NodePort    10.105.213.93   <none>        80:30798/TCP,443:30764/TCP   13m
ingress-nginx-controller-admission   ClusterIP   10.104.36.218   <none>        443/TCP                      13m

# k0s kubectl -n ingress-nginx get ingressclasses
NAME    CONTROLLER             PARAMETERS   AGE
nginx   k8s.io/ingress-nginx   <none>       13m

# k0s kubectl -n ingress-nginx annotate ingressclasses nginx ingressclass.kubernetes.io/is-default-class="true"

Deploymiseks sobib kasutada

# cat create-nodeport-based-ingress-service.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: web
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-server
  namespace: web
spec:
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
      - name: httpd
        image: httpd:2.4.53-alpine
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: web-server-service
  namespace: web
spec:
  selector:
    app: web
  ports:
    - protocol: TCP
      port: 5000
      targetPort: 80
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-server-ingress
  namespace: web
spec:
  ingressClassName: nginx
  rules:
  - host: web.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: web-server-service
            port:
              number: 5000

Deploymiseks sobib öelda

# k0s kubectl apply -f create-nodeport-based-ingress-service.yaml

Tulemuse vaatlemiseks tuleb töökohaarvutis tekitada /etc/hosts faili rida '192.168.10.164 web.example.com' ning paistab (vt eelmise väljundi nö dünaamiliselt seadistatud portide väärtusi)

• http://web.example.com:30798/
• https://web.example.com:30764/

Paigaldamine - nginx ingress kontroller + loadbalancer

Väited

• https://docs.k0sproject.io/v1.27.5+k0s.0/examples/nginx-ingress/ - 'Install NGINX using LoadBalancer'
• peab olema sooritatud eelpool kirjeldatud metallb paigaldus
• peab olema sooritatud eelmises punktis juhendatud nö nginx ingress kontrolleri NodePort paigaldus

Lõpuks tuleb nginx controller nodeport paigaldust kohendada - asendada NodePort -> LoadBalancer; ning veenduda, et muudatus kehtestub

# k0s kubectl edit service ingress-nginx-controller -n ingress-nginx
service/ingress-nginx-controller edited

# k0s kubectl get services -n ingress-nginx
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)                      AGE
ingress-nginx-controller             LoadBalancer   10.105.213.93   192.168.10.120   80:30798/TCP,443:30764/TCP   20m
ingress-nginx-controller-admission   ClusterIP      10.104.36.218   <none>           443/TCP                      20m

kus

• märgata external-ip väärtust 192.168.10.120
• pöörduda töökohaarvutist aadressilt https://web.example.com/ kusjuures see dns nimi peab lahenduma ip aadressiks 192.168.10.120.

Paigaldamine - nginx ingress kontroller + hostport

Väited

• https://docs.k0sproject.io/v1.27.5+k0s.0/examples/nginx-ingress - 'Install NGINX using host network'

Paigaldamiseks lähtepunktiks sobib kasutada vanilla k0s süsteemi, st puudub ingress kontroller ning puudub metallb. Esmalt kopeeritakse nginx ingress kontrolleri deploy.yaml fail

# wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/baremetal/deploy.yaml

failist leitakse üles seal juba olev Deployment sektsioon (ainuke), ja selles leitakse sobiv koht parameetrile 'hostNetwork: true' ja lisatakse

spec:
  template:
    spec:
      hostNetwork: true

Seejärel deploitakse custom seadistausega ingress kontroller

# k0s kubectl apply -f deploy.yaml

Tulemusena kuulab host port 80 ja 443 (nt kui 'netstat -lnpt' abil küsida). Ootus on et töökohaarvutist saab brauseriga küsida https://web.example.com/ kusjuures dns nimele vastab ip aadress 192.168.10.164 (st host ip aadress).

TODO

Paigaldamine - traefik

Väited

• https://docs.k0sproject.io/v1.27.5+k0s.0/examples/traefik-ingress/

k0s tarkvara paigaldamiseks sobib öelda

# curl -sSLf https://get.k0s.sh | sudo sh

kus

• TODO

Moodustada vaikimisi seadistusfail

# mkdir /etc/k0s
# k0s config create > /etc/k0s/k0s.yaml

Lisada seadistusfaili

• openebs storage
• metallb
• traefik

Kokku on seadistusfail selline, lisatud lõigud on tähistatud

# cat /etc/k0s/k0s.yaml
apiVersion: k0s.k0sproject.io/v1beta1
kind: ClusterConfig
metadata:
  creationTimestamp: null
  name: k0s
spec:
  api:
    address: 192.168.10.182
    k0sApiPort: 9443
    port: 6443
    sans:
    - 192.168.10.182
    - fe80::9867:8bff:fef0:3754
    tunneledNetworkingMode: false
  controllerManager: {}

# alates siit

  extensions:
    helm:
      repositories:
      - name: traefik
        url: https://traefik.github.io/charts
      - name: bitnami
        url: https://charts.bitnami.com/bitnami
      charts:
      - name: traefik
        chartname: traefik/traefik
        version: "20.5.3"
        namespace: default
      - name: metallb
        chartname: bitnami/metallb
        version: "2.5.4"
        namespace: default
        values: |2
          configInline:
            address-pools:
            - name: generic-cluster-pool
              protocol: layer2
              addresses:
             - 192.168.10.131-192.168.10.135
    storage:
      type: openebs_local_storage

# lopetades siin

  installConfig:
    users:
      etcdUser: etcd
      kineUser: kube-apiserver
      konnectivityUser: konnectivity-server
      kubeAPIserverUser: kube-apiserver
      kubeSchedulerUser: kube-scheduler
...

Paigaldatakse

# k0s install controller --single

Käivitada, seejuures tekitatakse systemd unit seadistus

# k0s start

systemd unit seadistust saab esitada

# systemctl status k0scontroller

Tulemusena on ootus et kubernetest saab kasutada, nt

# export KUBECONFIG=/var/lib/k0s/pki/admin.conf
# k0s kubectl get nodes
NAME          STATUS   ROLES           AGE     VERSION
k0s-traefik   Ready    control-plane   2m35s   v1.27.3+k0s

cert-manager kasutamine

TODO

Monitooringu kasutamine

TODO

Velero varundamise kasutamine

TODO

Kasulikud lisamaterjalid

• TODO