feat(metrics): add machine deployment metrics

Signed-off-by: rajaSahil <[email protected]>

Author: rajaSahil

cmd/machine-controller/main.go

@@ -393,6 +393,9 @@ func (bs *controllerBootstrap) Start(ctx context.Context) error {
 	machineCollector := machinecontroller.NewMachineCollector(ctx, bs.mgr.GetClient())
 	metrics.Registry.MustRegister(machineCollector)
 
+	machineDeploymentCollector := machinedeploymentcontroller.NewCollector(ctx, bs.mgr.GetClient())
+	metrics.Registry.MustRegister(machineDeploymentCollector)
+
 	if err := machinecontroller.Add(
 		ctx,
 		bs.opt.log,

pkg/controller/machinedeployment/metrics.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2019 The Machine Controller Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package machinedeployment
+
+import (
+	"context"
+	"github.com/prometheus/client_golang/prometheus"
+	"k8c.io/machine-controller/pkg/apis/cluster/v1alpha1"
+	ctrlruntimeclient "sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+const metricsPrefix = "machine_deployment_"
+
+type Collector struct {
+	ctx    context.Context
+	client ctrlruntimeclient.Client
+
+	replicas          *prometheus.Desc
+	availableReplicas *prometheus.Desc
+	readyReplicas     *prometheus.Desc
+	updatedReplicas   *prometheus.Desc
+}
+
+// NewCollector creates new machine deployment collector for metrics collection
+func NewCollector(ctx context.Context, client ctrlruntimeclient.Client) *Collector {
+	return &Collector{
+		ctx:    ctx,
+		client: client,
+		replicas: prometheus.NewDesc(
+			metricsPrefix+"replicas",
+			"The number of replicas defined for a machine deployment",
+			[]string{"name", "namespace"}, nil,
+		),
+		availableReplicas: prometheus.NewDesc(
+			metricsPrefix+"available_replicas",
+			"The number of available replicas for a machine deployment",
+			[]string{"name", "namespace"}, nil,
+		),
+		readyReplicas: prometheus.NewDesc(
+			metricsPrefix+"ready_replicas",
+			"The number of ready replicas for a machine deployment",
+			[]string{"name", "namespace"}, nil,
+		),
+		updatedReplicas: prometheus.NewDesc(
+			metricsPrefix+"updated_replicas",
+			"The number of replicas updated for a machine deployment",
+			[]string{"name", "namespace"}, nil,
+		),
+	}
+}
+
+// Describe implements the prometheus.Describe interface.
+func (c *Collector) Describe(desc chan<- *prometheus.Desc) {
+	desc <- c.replicas
+	desc <- c.readyReplicas
+	desc <- c.availableReplicas
+	desc <- c.readyReplicas
+}
+
+// Collect implements the prometheus.Collector interface.
+func (c *Collector) Collect(metrics chan<- prometheus.Metric) {
+	machineDeployments := &v1alpha1.MachineDeploymentList{}
+	if err := c.client.List(c.ctx, machineDeployments); err != nil {
+		return
+	}
+
+	for _, machineDeployment := range machineDeployments.Items {
+		metrics <- prometheus.MustNewConstMetric(
+			c.replicas,
+			prometheus.GaugeValue,
+			float64(machineDeployment.Status.Replicas),
+			machineDeployment.Name,
+			machineDeployment.Namespace,
+		)
+		metrics <- prometheus.MustNewConstMetric(
+			c.readyReplicas,
+			prometheus.GaugeValue,
+			float64(machineDeployment.Status.ReadyReplicas),
+			machineDeployment.Name,
+			machineDeployment.Namespace,
+		)
+		metrics <- prometheus.MustNewConstMetric(
+			c.availableReplicas,
+			prometheus.GaugeValue,
+			float64(machineDeployment.Status.AvailableReplicas),
+			machineDeployment.Name,
+			machineDeployment.Namespace,
+		)
+		metrics <- prometheus.MustNewConstMetric(
+			c.updatedReplicas,
+			prometheus.GaugeValue,
+			float64(machineDeployment.Status.UpdatedReplicas),
+			machineDeployment.Name,
+			machineDeployment.Namespace,
+		)
+	}
+}