Please enable JavaScript.

Coggle requires JavaScript to display documents.

Kubernetes (object model (object types (pods (scheduled together on the…

- - - - metadata
        
        labels
        
        app:nginx
      - spec
        
        containers
        
        name
        
        ports
        
        containerPort:80
        
        image
  - - - scheduled together on the same host
      - share same network namespace
      - mount the same volumes
      - the smallest and simplest Kubernetes object
      - the unit of deployment in Kubernetes
      - a single instance of the application
      - a logical collection of one or more containers
      - ephemeral in nature
      - do not have the capability to self-heal
    - - deployments
        
        provide declarative updates to Pods and ReplicaSets
      - replicaControllers
        
        replicaSets
        
        can be used independently, but they are mostly used by Deployments to orchestrate the Pod creation, deletion, and updates
      - used with Pods to handle a Pod's replication, fault tolerance, self-heal, etc
    - - service endpoint
      - service discovery
        
        environment variables
        
        dns
      - access scope
        
        cluster
        
        cluster and external
        
        map to an external object
      - service type
        
        clusterIP
        
        accessible only within the cluster
        
        nodePort
        
        redirect all the traffic to the assigned ClusterIP
        
        externalIp
        
        externalName
        
        a special ServiceType, that has no Selectors and does not define any endpoints
        
        returns a CNAME record of an externally configured service
        
        The primary use case of this ServiceType is to make externally configured services like my-database.example.com available inside the cluster, using just the name, like my-database, to other services inside the same Namespace
        
        loadbalancer
        
        NodePort and ClusterIP Services are automatically created, and the external load balancer will route to them
        
        The Services are exposed at a static port on each Worker Node
        
        The Service is exposed externally using the underlying Cloud provider's load balancer feature
      - logically groups Pods and a policy to access them. This grouping is achieved via Labels and Selectors
    - - volume types
        
        hostPath
        
        If the Pod dies, the content of the Volume is still available on the host
        
        emptyDir
        
        An empty Volume is created for the Pod as soon as it is scheduled on the Worker Node. The Volume's life is tightly coupled with the Pod. If the Pod dies, the content of emptyDir is deleted forever
        
        gcePersistentDisk
        
        can mount a Google Compute Engine (GCE) persistent disk into a Pod
        
        awsElasticBlockStore
        
        can mount an AWS EBS Volume into a Pod
        
        nfs
        
        can mount an NFS share
        
        iscsi
        
        secret
        
        can pass sensitive information, such as passwords, to Pods
        
        persistentVolumeClaim
        
        persistent volumes
        
        a network attached storage in the cluster, which is provisioned by the administrator
        
        persistent volumes claim
        
        a request for storage by a user
    - - Layer 7 HTTP load balancer for Services
      - TLS (Transport Layer Security)
      - Name-based virtual hosting
      - Path-based routing
      - Custom rules
      - Ingress controller
        
        watches the Master Node's API Server for changes in the Ingress resources and updates the Layer 7 load balancer accordingly
  - - - contains the objects created by the Kubernetes system
    - - a special namespace, which is readable by all users and used for special purposes, like bootstrapping a cluster
    - - contains the objects which belong to any other namespace
- - - - Plugins
        
        3rd party plugin
        
        MACvlan plugin
        
        IPvlan plugin
        
        bridge plugin
        
        loopback plugin
      - inside pod
        
        Network namespaces
      - across nodes
        
        Calico
        
        flannel
        
        Google container engine
        
        weave
      - external world
        
        kube-proxy