= Sesión 12 : k8s (traefik)
{{tag>devops cursos k8s}}
== k8s
=== lab (traefik)
  * traefik como ingress controller:<code yaml; traefik-rbac.yaml>
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller
rules:
  - apiGroups:
      - ""
    resources:
      - services
      - endpoints
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
- kind: ServiceAccount
  name: traefik-ingress-controller
  namespace: kube-system</code>
<code yaml; traekik-daemonset.yaml>
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
---
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress-lb
spec:
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress-lb
        name: traefik-ingress-lb
    spec:
      serviceAccountName: traefik-ingress-controller
      terminationGracePeriodSeconds: 60
      containers:
      - image: traefik
        name: traefik-ingress-lb
        ports:
        - name: http
          containerPort: 80
          hostPort: 80
        - name: admin
          containerPort: 8080
          hostPort: 8080
        securityContext:
          capabilities:
            drop:
            - ALL
            add:
            - NET_BIND_SERVICE
        args:
        - --api
        - --kubernetes
        - --logLevel=INFO
---
kind: Service
apiVersion: v1
metadata:
  name: traefik-ingress-service
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  ports:
    - protocol: TCP
      port: 80
      name: web
    - protocol: TCP
      port: 8080
      name: admin
</code>
esta versión no se ha desplegado correctamente VS la anterior
<code yaml; traefik-deployment.yaml>
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: traefik-ingress-controller
  namespace: kube-system
  labels:
    k8s-app: traefik-ingress-lb
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: traefik-ingress-lb
  template:
    metadata:
      labels:
        k8s-app: traefik-ingress-lb
        name: traefik-ingress-lb
    spec:
      serviceAccountName: traefik-ingress-controller
      terminationGracePeriodSeconds: 60
      containers:
      - image: traefik
        name: traefik-ingress-lb
        ports:
        - name: http
          containerPort: 80
        - name: admin
          containerPort: 8080
        args:
        - --api
        - --kubernetes
        - --logLevel=INFO
---
kind: Service
apiVersion: v1
metadata:
  name: traefik-ingress-service
  namespace: kube-system
spec:
  selector:
    k8s-app: traefik-ingress-lb
  ports:
    - protocol: TCP
      port: 80
      name: web
    - protocol: TCP
      port: 8080
      name: admin
  type: NodePort
</code>

=== lab (who)
[[https://medium.com/@geraldcroes/kubernetes-traefik-101-when-simplicity-matters-957eeede2cf8]]

<code yaml; whoami-deployment.yaml>
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: whoami-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: whoami
  template:
    metadata:
      labels:
        app: whoami
    spec:
      containers:
      - name: whoami-container
        image: containous/whoami
</code>

<code yaml; whoami-service.yaml>
apiVersion: v1
kind: Service
metadata:
  name: whoami-service
spec:
  ports:
  - name: http
    targetPort: 80
    port: 80
  selector:
    app: whoami
</code>

<code yaml; whoami-ingress.yaml>
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: whoami-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: whoami.localhost
    http:
      paths:
      - path: /
        backend:
          serviceName: whoami-service
          servicePort: http
</code>

si queremos NO tocar el localhost para que resuelva **whoami.localhost**, podemos lanzar este comando: ''curl -H 'Host: whoami.localhost' 192.168.99.100''

también podemos usar [[http://nip.io]]:
<code yaml; whoami-ingress.yaml>
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: whoami-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: whoami-192-168-99-100.nip.io
    http:
      paths:
      - path: /
        backend:
          serviceName: whoami-service
          servicePort: http
</code>
<code yaml; whoareyou-deployment.yaml>
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: whoareyou-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: whoareyou
  template:
    metadata:
      labels:
        app: whoareyou
    spec:
      containers:
      - name: whoareyou-container
        image: containous/whoami
---
apiVersion: v1
kind: Service
metadata:
  name: whoareyou-service
spec:
  ports:
  - name: http
    targetPort: 80
    port: 80
  selector:
    app: whoareyou
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: whoareyou-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: whoareyou-192-168-99-100.nip.io
    http:
      paths:
      - path: /
        backend:
          serviceName: whoareyou-service
          servicePort: http
</code>

=== lab (flocker)
  * ''minukube dashboard'' : lanza proceso dashboard web

==== instalar (sin flocker) un WP y MYSQL
  * mysql:<code yaml; mysql-secrets.yaml>
apiVersion: v1
kind: Secret
metadata:
  name: mysql-secret
type: Opaque
data:
  password: cm9vdA==
</code>
<code yaml; mysql.yaml>
apiVersion: v1
kind: Service
metadata:
  name: wordpress-mysql
  labels:
    app: wordpress
spec:
  ports:
    - port: 3306
  selector:
    app: wordpress
    tier: mysql
  clusterIP: None
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
  labels:
    app: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress-mysql
  labels:
    app: wordpress
spec:
  selector:
    matchLabels:
      app: wordpress
      tier: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: wordpress
        tier: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-secret
              key: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-pv-claim
</code>
<code yaml; wordpress.yaml>
apiVersion: v1
kind: Service
metadata:
  name: wordpress-service
  labels:
    app: wordpress
spec:
  ports:
  - name: http
    targetPort: 80
    port: 80
# - port: 80
  selector:
    app: wordpress
    tier: frontend
#  type: LoadBalancer
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: wp-pv-claim
  labels:
    app: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
#  replicas: 1
  selector:
    matchLabels:
      app: wordpress
      tier: frontend
#  strategy:
#    type: Recreate
  template:
    metadata:
      labels:
        app: wordpress
        tier: frontend
    spec:
      containers:
      - image: wordpress:4.8-apache
        name: wordpress
        env:
        - name: WORDPRESS_DB_HOST
          value: wordpress-mysql
        - name: WORDPRESS_DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mysql-secret
              key: password
        ports:
        - containerPort: 80
          name: wordpress
        volumeMounts:
        - name: wordpress-persistent-storage
          mountPath: /var/www/html
      volumes:
      - name: wordpress-persistent-storage
        persistentVolumeClaim:
          claimName: wp-pv-claim
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: wordpress-ingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: wordpress-192-168-99-100.nip.io
    http:
      paths:
      - path: /
        backend:
          serviceName: wordpress-service
          servicePort: http
</code>


  * ''kubectl edit <objeto>''
  * ''kubectl scale --replicas=3 deployment/<pod>''
  * ''kubectl autscale --min=3 --max=10 --cpu-percent=2 deplyment/<pod>''
  * ''kubectl get all --all-namespaces''
  * ''kubetel get all --namespace=<namespace>''
    * lo que no se muestra:
      * ''kubectl get pv''
      * ''kubectl get pvc''
      * ''kubectl get ingresses''
  * ''kubectl api-resources''

==== flocker
  * instalación: [[https://flocker.readthedocs.io/en/latest/kubernetes-integration/]] <- fails!
  * [[https://github.com/linux-on-ibm-z/docs/wiki/Building-Flocker]] <- fails!
  * [[https://flocker.readthedocs.io/en/latest/supported/flockercontainers.html#flocker-containers]]

== objetos kubernetes
  * replicationcontroller: [[https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller/]]
  * replicaset: [[https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/]]
  * deployment: [[https://kubernetes.io/docs/concepts/workloads/controllers/deployment/]]
    * rollout, concepto de log de revisiones de deployment
    * sección deployment, sección replicaset, sección pod
  * daemonset: [[https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/]]
  * statefulsets: [[https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/]]
    * storageclassname : servicio de gestión de volúmenes
  * persistentvolumes: [[https://kubernetes.io/docs/concepts/storage/persistent-volumes/]]
    * modos: 
      * readWriteOnce : solo un POD puede usar ese volumen para lectura/escritura
      * readOnlyMany
      * readWriteMany
    * persistentVolumeProvisioning: [[https://github.com/kubernetes/examples/blob/master/staging/persistent-volume-provisioning/README.md]]
    * storage classes: [[https://kubernetes.io/docs/concepts/storage/storage-classes/]]
  * secrets: [[https://kubernetes.io/docs/concepts/configuration/secret/]]
  * labels: [[https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/]]
== otros
  * ''helm fetch <>'' : descarga