cleanup: move pkg/ to internal/

The internal/ directory in Go has a special meaning, and indicates that
those packages are not meant for external consumption. Ceph-CSI does
provide public APIs for other projects to consume. There is no plan to
keep the API of the internally used packages stable.

Closes: #903
Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/liveness/liveness.go

@@ -0,0 +1,94 @@
+/*
+Copyright 2019 The Ceph-CSI 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 liveness
+
+import (
+	"context"
+	"time"
+
+	"github.com/ceph/ceph-csi/internal/util"
+
+	connlib "github.com/kubernetes-csi/csi-lib-utils/connection"
+	"github.com/kubernetes-csi/csi-lib-utils/metrics"
+	"github.com/kubernetes-csi/csi-lib-utils/rpc"
+	"github.com/prometheus/client_golang/prometheus"
+	"google.golang.org/grpc"
+	"k8s.io/klog"
+)
+
+var (
+	liveness = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "csi",
+		Name:      "liveness",
+		Help:      "Liveness Probe",
+	})
+)
+
+func getLiveness(timeout time.Duration, csiConn *grpc.ClientConn) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	klog.V(5).Info("Sending probe request to CSI driver")
+	ready, err := rpc.Probe(ctx, csiConn)
+	if err != nil {
+		liveness.Set(0)
+		klog.Errorf("health check failed: %v", err)
+		return
+	}
+
+	if !ready {
+		liveness.Set(0)
+		klog.Error("driver responded but is not ready")
+		return
+	}
+	liveness.Set(1)
+	klog.V(3).Infof("Health check succeeded")
+}
+
+func recordLiveness(endpoint, drivername string, pollTime, timeout time.Duration) {
+	liveMetricsManager := metrics.NewCSIMetricsManager(drivername)
+	// register prometheus metrics
+	err := prometheus.Register(liveness)
+	if err != nil {
+		klog.Fatalln(err)
+	}
+
+	csiConn, err := connlib.Connect(endpoint, liveMetricsManager)
+	if err != nil {
+		// connlib should retry forever so a returned error should mean
+		// the grpc client is misconfigured rather than an error on the network
+		klog.Fatalf("failed to establish connection to CSI driver: %v", err)
+	}
+
+	// get liveness periodically
+	ticker := time.NewTicker(pollTime)
+	defer ticker.Stop()
+	for range ticker.C {
+		getLiveness(timeout, csiConn)
+	}
+}
+
+// Run starts liveness collection and prometheus endpoint
+func Run(conf *util.Config) {
+	klog.V(3).Infof("Liveness Running")
+
+	// start liveness collection
+	go recordLiveness(conf.Endpoint, conf.DriverName, conf.PollTime, conf.PoolTimeout)
+
+	// start up prometheus endpoint
+	util.StartMetricsServer(conf)
+}