Install DTC

This topic describes installing the Dynamic Traffic Controller (DTC) on a supported Kubernetes cluster. This document assumes you have already installed ExternalDNS and configured it for your DNS provider (likely NS1). For details on
installing ExternalDNS, see ExternalDNS.

Dynamic Traffic Controller Configuration Parameters

The following parameters are used to configure the DTC as described in the DTC YAML file.

DTC Parameters with the ServiceAccount Object Schema

Parameter	Parameter Type	Description	Required
apiVersion	String	The RBAC API version. The value must be rbac.authorization.k8s.io/v1.	Mandatory
kind	String	The name of a particular object schema. The value must be ServiceAccount.	Mandatory
metadata	Object	The metadata describes the parameters (names and types) and attributes that have been applied.	Mandatory

DTC Metadata Parameters with the ServiceAccount Object Schema

Parameter	Parameter Type	Description	Required
name	String	The name of the Service Account that you define.	Mandatory

DTC Parameters with the ClusterRole Object Schema

The following parameters are used to configure the Dynamic Traffic Controller (DTC) ClusterRole object as described in the DTC YAML file.

Parameter	Parameter Type	Description	Required
apiVersion	String	The RBAC API version. The value must be rbac.authorization.k8s.io/v1.	Mandatory
kind	String	The name of a particular object schema. The value must be ClusterRole.	Mandatory
metadata	Object	The metadata describes the parameters (names and types) and attributes that have been applied.	Mandatory
rules	Object	This parameter holds information that describes a policy rule. It does not contain information about who the rule applies to or which namespace the rule applies to.	Mandatory

DTC Metadata Parameters with the ClusterRole Object Schema

Parameter	Parameter Type	Description	Required
name	String	The name of the role that you define.	Mandatory

DTC Rules Parameters with the ClusterRole Object Schema

Parameter	Parameter Type	Description	Required
apiGroups	String Array	The name of the API group that contains the resources. If multiple API groups are specified, an action requested against one of the resources in any API group is allowed. You must not add an asterisk * to represent all API groups. An empty apiGroup represents the core API group.	Mandatory
resources	String Array	This contains an array of optional list of names that the rule applies to. An empty set means that all resources are allowed.	Mandatory
verbs	String Array	A list of verbs that apply to all the resource types contained in this rule. * represents all verbs that apply to the resource types.	Mandatory

DTC Parameters with the ClusterRoleBinding Object Schema

The following parameters are used to configure the Dynamic Traffic Controller (DTC) ClusterRoleBinding object as described in the DTC YAML file.

Parameter	Parameter Type	Description	Required
apiVersion	String	The RBAC API version. The value must be rbac.authorization.k8s.io/v1.	Mandatory
kind	String	The name of a particular object schema. The value must be ClusterRole.	Mandatory
metadata	Object	The metadata describes the parameters (names and types) and attributes that have been applied.	Mandatory
roleRefs	Object	This a reference to the role being granted.	Mandatory
subjects	Object	The name of the resource and schema to which the role is applied. For each namespace, the subjects must be added separately in an array.	Mandatory

DTC Metadata Parameters with the ClusterRoleBinding Object Schema

Parameter	Parameter Type	Description	Required
name	String	The name of the role that you define.	Mandatory

DTC Role Reference Parameters with the ClusterRoleBinding Object Schema

Parameter	Parameter Type	Description	Required
apiVersion	String	The KubeSlice Controller API version. A set of resources that are exposed together, along with the version. The value must be rbac.authorization.k8s.io/v1 for Kubernetes (K8s) roles.	Mandatory
kind	String	The kind of the role that is being referenced. The value must be ClusterRole for a Kubernetes (K8s) role.	Mandatory
name	String	The name of the role that you assign to the slice and namespaces onboarded onto that slice.	Mandatory

DTC Subjects Parameters with the ClusterRoleBinding Object Schema

Parameter	Parameter Type	Description	Required
kind	String	The type of the resource for which you assign the role. For example, the kind is a User, ServiceAccount, or a Group.	Mandatory
name	String	The name of the resource to which the role is applied.	Mandatory
namespace	String	The namespace that contains the resource to which the role is applied	Mandatory

DTC Parameters with the Deployment Object Schema

The following parameters are used to configure the Dynamic Traffic Controller (DTC) Deployment object as described in the DTC YAML file.

Parameter	Parameter Type	Description	Required
apiVersion	String	The RBAC API version. The value must be rbac.authorization.k8s.io/v1.	Mandatory
kind	String	The name of a particular object schema. The value must be ClusterRole.	Mandatory
metadata	Object	The metadata describes the parameters (names and types) and attributes that have been applied.	Mandatory
spec	Object	The specification of the desired state of an object.	Mandatory

DTC Metadata Parameters with the Deployment Object Schema

Parameter	Parameter Type	Description	Required
labels	Object	A key value pair to use with the matchLabels selector.	Mandatory	labels
name	String	The name of the application that you deploy.	Mandatory
namespace	String	The namespace on which you deploy the application.	Mandatory

DTC Metadata Labels Parameters

Parameter	Parameter Type	Description	Required
k8s-app	String	A selector to match deployment pods to the deployment.	Mandatory

DTC Spec Parameters with the Deployment Object Schema

Parameter	Parameter Type	Description	Required
replicas	String	The number of dns-controller pods to be created.	Mandatory
selector	Object	The label which identifies DTC pods.	Mandatory
template	Object	The pod definition for the DTC deployment.	Mandatory

DTC Spec Selector Parameters

Parameter	Parameter Type	Description	Required
matchLabels	Object	Specifies the labels to match when associating pods with a deployment.	Mandatory

DTC Spec Selector Match Labels Parameters

Parameter	Parameter Type	Description	Required
k8s-app	String	The key value selector pair for the deployment.	Mandatory

DTC Spec Template Parameters

Parameter	Parameter Type	Description	Required
metadata	Object	The metadata of the deployment such as it's name and namespace.	Mandatory
spec	The deployment specifications such as the number of replicas and template.	Object	Mandatory

DTC Template Metadata Parameters

Parameter	Parameter Type	Description	Required
labels	Object	A key value pair label which will be used by selectors to target the DTC deployment and pods.	Mandatory
name	String	The name of the DTC pod.	Mandatory

DTC Template Metadata Labels Parameters

Parameter	Parameter Type	Description	Required
k8s-app	String	A selector tvo match deployment pods to the deployment.	Mandatory

DTC Template Spec Parameters

Parameter	Parameter Type	Description	Required
serviceAccountName	String	The name of the service account.	Mandatory
containers	Object	Mandatory

DTC Template Spec Container Parameters

Parameter	Parameter Type	Description	Required
name	String	The name of the container within the pod.	Mandatory
image	String	The latest image for the DTC.	Mandatory
imagePullPolicy	String	Image pull policy determines when a new image should be pulled from a Docker repository.	Mandatory
resources	Object	This contains an array of optional list of names that the rule applies to. An empty set means that all resources are allowed.	Mandatory
serviceAccountName	String	The name of the service account.	Mandatory

DTC Container Resources Parameters

Parameter	Parameter Type	Description	Required
limits	Object	The section contains the limit object that sets limits for CPU, memory, and pod count.	Mandatory
requests	Object	The section contains the requests object that sets scheduling requirements for CPU, memory, and pod count.	Mandatory

DTC Resource Limits Parameters

Parameter	Parameter Type	Description	Required
cpu	String	The maximum allowable CPU usage by the pod.	Mandatory
memory	String	The maximum allowable memory usage by the pod.	Mandatory

DTC Resource Requests Parameters

Parameter	Parameter Type	Description	Required
cpu	String	The minimum amount of CPU which must be available to schedule a pod on a node.	Mandatory
memory	String	The minimum amount of memory which must be available to schedule a pod on a node.	Mandatory

Create a Dynamic Traffic Controller YAML File

info

The following manifest file contains default resource requests which should be sufficient for most users. Be sure to watch your resource utilization as you add services to the Dynamic Traffic Controller and make adjustments as required.

Copy the following configuration into a new descriptively named YAML file, such as gcp-dynamic-traffic-controller.yaml.

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dns-controller-sa
  namespace: external-dns
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: dns-controller-clusterrole
  namespace: external-dns
rules:
  - apiGroups: ["metrics.k8s.io"]
    resources: ["pods"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["services"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["extensions", "networking.k8s.io/v1"]
    resources: ["ingress"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["extensions", "networking.k8s.io"]
    resources: ["ingresses"]
    verbs: ["get", "list", "watch", "update"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: dns-controller-clusterrolebinding
  namespace: external-dns
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: dns-controller-clusterrole
subjects:
  - kind: ServiceAccount
    name: dns-controller-sa
    namespace: external-dns
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: dns-controller
  name: dns-controller
  namespace: external-dns
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: dns-controller
  template:
    metadata:
      labels:
        k8s-app: dns-controller
    spec:
      containers:
        - name: dns-controller
          image: "aveshasystems/dynamic_traffic_controller:latest"
          imagePullPolicy: IfNotPresent
          resources:
            requests:
              cpu: 35m
              memory: 50Mi
            limits:
              cpu: 75m
              memory: 100Mi
      serviceAccountName: dns-controller-sa

Apply the Dynamic Traffic Controller YAML File

Use the following kubectl command to install all required components of the Dynamic Traffic Controller.

kubectl apply -f gcp-dynamic-traffic-controller.yaml -n external-dns

Expected Output:

serviceaccount/dns-controller-sa created
clusterrole.rbac.authorization.k8s.io/dns-controller-clusterrole created
clusterrolebinding.rbac.authorization.k8s.io/dns-controller-clusterrolebinding created
deployment.apps/dns-controller created

Wait a few moments to a minute, and then run the following command to verify the Dynamic Traffic Controller's pod is running without error.

kubectl get pods -n external-dns