Services

Every App needs to be exposed to something, either an UI, API or other containers.However with Kubernetes we don’t directly connect to the containers running the App, because those might be on another node or there might be multiple “high available” containers for the App. Instead we use what is called Services. Services are simply put “Internal Load-Balancers”, they also guaranteed to be reachable by (internal!) DNS name and (in some cases) prevent traffic from reaching your App when the healthcheck isn’t finished yet (or is failing).

Two kinds of services

Main Service

Every App must have a main service, the primary connection for users or other apps, whether it’s a webUI, an API, a database connection or something else. Keep in mind that every App is unique, some may have one service called main, while others may need multiple services with distinct names. Also, every App uses different ports, so make sure to alter accordingly.

- variable: service
  group: "Networking"
  label: "Configure Service(s)"
  schema:
    type: dict
    attrs:
      - variable: main
        label: "Main Service"
        description: "The Primary service on which the healthcheck runs, often the webUI"
        schema:
          type: dict
          attrs:
            - variable: enabled
              label: "Enable the service"
              schema:
                type: boolean
                default: true
                hidden: true
            - variable: type
              label: "Service Type"
              description: "ClusterIP's are only internally available, nodePorts expose the container to the host node System, Loadbalancer exposes the service using the system loadbalancer"
              schema:
                type: string
                default: "NodePort"
                enum:
                  - value: "NodePort"
                    description: "NodePort"
                  - value: "ClusterIP"
                    description: "ClusterIP"
                  - value: "LoadBalancer"
                    description: "LoadBalancer"
            - variable: loadBalancerIP
              label: "LoadBalancer IP"
              description: "LoadBalancerIP"
              schema:
                show_if: [["type", "=", "LoadBalancer"]]
                type: string
                default: ""
                required: true
            - variable: externalIPs
              label: "External IP's"
              description: "External IP's"
              schema:
                show_if: [["type", "=", "LoadBalancer"]]
                type: list
                default: []
                items:
                  - variable: externalIP
                    label: "External IP"
                    required: true
                    schema:
                      type: string
            - variable: ports
              label: "Service's Port(s) Configuration"
              schema:
                type: dict
                attrs:
                  - variable: main
                    label: "Main Service Port Configuration"
                    schema:
                      type: dict
                      attrs:
                        - variable: enabled
                          label: "Enable the port"
                          schema:
                            type: boolean
                            default: true
                            hidden: true
                        - variable: protocol
                          label: "Port Type"
                          schema:
                            type: string
                            default: "HTTP"
                            hidden: false
                            enum:
                              - value: HTTP
                                description: "HTTP"
                              - value: "HTTPS"
                                description: "HTTPS"
                              - value: TCP
                                description: "TCP"
                              - value: "UDP"
                                description: "UDP"
                        - variable: port
                          label: "Container Port"
                          schema:
                            type: int
                            default: 5076
                            editable: false
                            hidden: true
                        - variable: targetport
                          label: "Target Port"
                          description: "This port exposes the container port on the service"
                          schema:
                            type: int
                            default: 5076
                            editable: true
                            hidden: false
                            required: true
                        - variable: nodePort
                          label: "Node Port (Optional)"
                          description: "This port gets exposed to the node. Only considered when service type is NodePort"
                          schema:
                            type: int
                            min: 9000
                            max: 65535
                            default: 36041
                            required: true