remove master from codebase and where possible from docs

No effort is small enough to justify inactivity.

We are following the example we get from ClusterAPI and the Kubernetes
community: kubernetes-sigs/cluster-api#3285

Author: Gianluca Arbezzano

README.md

@@ -67,7 +67,7 @@ To generate your cluster yaml:
    * `SSH_KEY` - The path to an ssh public key to place on all of the machines. If not set, it will use whichever ssh keys are defined for your project.
    * `POD_CIDR` - The CIDR to use for your pods; if not set, see defaults below
    * `SERVICE_CIDR` - The CIDR to use for your services; if not set, see defaults below
-   * `MASTER_NODE_TYPE` - The Packet node type to use for control plane nodes; if not set, see defaults below
+   * `CONTROLPLANE_NODE_TYPE` - The Packet node type to use for control plane nodes; if not set, see defaults below
    * `WORKER_NODE_TYPE` - The Packet node type to use for worker nodes; if not set, see defaults below
    * `WORKER_MACHINE_COUNT` - The number of worker machines to deploy; if not set, cluster-api itself (not the Packet implementation) defaults to 0 workers.
 1. Run the cluster generation command:
@@ -100,9 +100,9 @@ If you do not change the generated `yaml` files, it will use defaults. You can l
 * pod CIDR: `172.26.0.0/16`
 * service domain: `cluster.local`
 * cluster name: `test1-<random>`, where random is a random 5-character string containing the characters `a-z0-9`
-* master node type: `t1.small`
+* control plane node type: `t1.small`
 * worker node type: `t1.small`
-* worker and master OS type: `ubuntu_18_04`
+* worker and control plane OS type: `ubuntu_18_04`
 
 #### Apply Your Cluster
 
@@ -128,7 +128,7 @@ The actual machines are deployed using `kubeadm`. The deployment process uses th
 
 1. When a new `Cluster` is created:
    * if the appropriate `Secret` does not include a CA key/certificate pair, create one and save it in that `Secret`
-2. When a new master `Machine` is created:
+2. When a new control plane `Machine` is created:
    * retrieve the CA certificate and key from the appropriate Kubernetes `Secret`
    * launch a new server instance on Packet
    * set the `cloud-init` on the instance to run `kubeadm init`, passing it the CA certificate and key
@@ -156,7 +156,7 @@ When trying to install a new machine, the logic is as follows:
 Important notes:
 
 * There can be multiple `machineParams` entries for each `userdata`, enabling one userdata script to be used for more than one combination of OS and Kubernetes versions.
-* There are versions both for `controlPlane` and `kubelet`. `master` servers will match both `controlPlane` and `kubelet`; worker nodes will have no `controlPlane` entry.
+* There are versions both for `controlPlane` and `kubelet`. `control plane` servers will match both `controlPlane` and `kubelet`; worker nodes will have no `controlPlane` entry.
 * The `containerRuntime` is installed as is. The value of `containerRuntime` will be passed to the userdata script as `${CR_PACKAGE}`, to be installed as desired.
 
 ## References

api/v1alpha3/tags.go

@@ -17,6 +17,6 @@ limitations under the License.
 package v1alpha3
 
 const (
-	MasterTag = "kubernetes.io/role:master"
-	WorkerTag = "kubernetes.io/role:node"
+	ControlPlaneTag = "kubernetes.io/role:master"
+	WorkerTag       = "kubernetes.io/role:node"
 )

docs/concepts/machine.md

@@ -7,7 +7,7 @@ This is an example of it:
 apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
 kind: PacketMachine
 metadata:
-  name: "qa-master-0"
+  name: "qa-controlplane-0"
 spec:
   OS: "ubuntu_18_04"
   billingCycle: hourly
@@ -42,7 +42,7 @@ You can specify the reservation ID using the field `hardwareReservationID`:
 apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
 kind: PacketMachine
 metadata:
-  name: "qa-master-0"
+  name: "qa-controlplane-0"
 spec:
   OS: "ubuntu_18_04"
   facility:

pkg/cloud/packet/client.go

@@ -88,7 +88,7 @@ func (p *PacketClient) NewDevice(machineScope *scope.MachineScope, extraTags []s
 			return nil, fmt.Errorf("error executing control-plane userdata template: %v", err)
 		}
 		userData = stringWriter.String()
-		tags = append(tags, infrastructurev1alpha3.MasterTag)
+		tags = append(tags, infrastructurev1alpha3.ControlPlaneTag)
 	} else {
 		tags = append(tags, infrastructurev1alpha3.WorkerTag)
 	}

pkg/cloud/packet/scope/machine.go

@@ -122,7 +122,7 @@ func (m *MachineScope) IsControlPlane() bool {
 // Role returns the machine role from the labels.
 func (m *MachineScope) Role() string {
 	if util.IsControlPlaneMachine(m.Machine) {
-		return infrav1.MasterTag
+		return infrav1.ControlPlaneTag
 	}
 	return infrav1.WorkerTag
 }

scripts/generate-cluster.sh

@@ -30,7 +30,7 @@ TEMPLATE_OUT=./out/cluster.yaml
 DEFAULT_KUBERNETES_VERSION="v1.18.2"
 DEFAULT_POD_CIDR="172.25.0.0/16"
 DEFAULT_SERVICE_CIDR="172.26.0.0/16"
-DEFAULT_MASTER_NODE_TYPE="t1.small"
+DEFAULT_CONTROLPLANE_NODE_TYPE="t1.small"
 DEFAULT_WORKER_NODE_TYPE="t1.small"
 DEFAULT_NODE_OS="ubuntu_18_04"
 DEFAULT_WORKER_MACHINE_COUNT=3
@@ -62,7 +62,7 @@ CLUSTER_NAME=${CLUSTER_NAME:-${DEFAULT_CLUSTER_NAME}}
 POD_CIDR=${POD_CIDR:-${DEFAULT_POD_CIDR}}
 SERVICE_CIDR=${SERVICE_CIDR:-${DEFAULT_SERVICE_CIDR}}
 WORKER_NODE_TYPE=${WORKER_NODE_TYPE:-${DEFAULT_WORKER_NODE_TYPE}}
-MASTER_NODE_TYPE=${MASTER_NODE_TYPE:-${DEFAULT_MASTER_NODE_TYPE}}
+CONTROLPLANE_NODE_TYPE=${CONTROLPLANE_NODE_TYPE:-${DEFAULT_CONTROLPLANE_NODE_TYPE}}
 WORKER_MACHINE_COUNT=${WORKER_MACHINE_COUNT:-${DEFAULT_WORKER_MACHINE_COUNT}}
 CONTROL_PLANE_MACHINE_COUNT=${CONTROL_PLANE_MACHINE_COUNT:-${DEFAULT_CONTROL_PLANE_MACHINE_COUNT}}
 NODE_OS=${NODE_OS:-${DEFAULT_NODE_OS}}
@@ -73,7 +73,7 @@ PROJECT_ID=${PACKET_PROJECT_ID}
 FACILITY=${PACKET_FACILITY}
 
 # and now export them all so envsubst can use them
-export PROJECT_ID FACILITY NODE_OS WORKER_NODE_TYPE MASTER_NODE_TYPE POD_CIDR SERVICE_CIDR SSH_KEY KUBERNETES_VERSION WORKER_MACHINE_COUNT CONTROL_PLANE_MACHINE_COUNT
+export PROJECT_ID FACILITY NODE_OS WORKER_NODE_TYPE CONTROLPLANE_NODE_TYPE POD_CIDR SERVICE_CIDR SSH_KEY KUBERNETES_VERSION WORKER_MACHINE_COUNT CONTROL_PLANE_MACHINE_COUNT
 ${CLUSTERCTL} ${CONFIG_OPT} config cluster ${CLUSTER_NAME} --from file://$PWD/templates/cluster-template.yaml > $TEMPLATE_OUT
 
 echo "Done! See output file at ${TEMPLATE_OUT}. Run:"