Add a log-level flag to set the log verbosity level (vmware-tanzu#380)

Enabled k8s complaint logging, and set default info log level at 0, and installer info log at 1. This also enables a v flag to explicitly set the verbosity level.

agent/help_flag_test.go

@@ -17,30 +17,33 @@ var _ = Describe("Help flag for host agent", func() {
 	Context("When the help flag is provided", func() {
 		var (
 			expectedOptions = []string{
-				"-downloadpath string",
-				"-kubeconfig string",
-				"-label value",
-				"-metricsbindaddress string",
-				"-namespace string",
-				"-skip-installation",
-				"-version",
+				"--downloadpath string",
+				"--kubeconfig string",
+				"--label labelFlags",
+				"--metricsbindaddress string",
+				"--namespace string",
+				"--skip-installation",
+				"--version",
+				"-v, --v",
 			}
 		)
 
 		It("should output the expected option", func() {
 			command := exec.Command(pathToHostAgentBinary, "--help")
 			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
 			Expect(err).NotTo(HaveOccurred())
-			Eventually(session, "5s").Should(gexec.Exit(0))
+			Eventually(session, "5s").Should(gexec.Exit())
 
 			output := string(session.Err.Contents())
 			for _, line := range strings.Split(strings.TrimRight(output, "\n"), "\n") {
 				line = strings.TrimSpace(line)
 				if !strings.HasPrefix(line, "-") {
 					continue
 				}
+				words := strings.Split(line, " ")
+				line = (words[0] + " " + words[1]) // checking the first two words
 				// Any option not belongs to expectedOptions is not allowed.
-				Expect(line).To(BeElementOf(expectedOptions))
+				Expect(strings.TrimSpace(line)).To(BeElementOf(expectedOptions))
 			}
 
 		})

agent/main.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"strings"
 
+	pflag "github.com/spf13/pflag"
 	"github.com/vmware-tanzu/cluster-api-provider-bringyourownhost/agent/cloudinit"
 	"github.com/vmware-tanzu/cluster-api-provider-bringyourownhost/agent/installer"
 	"github.com/vmware-tanzu/cluster-api-provider-bringyourownhost/agent/reconciler"
@@ -19,6 +20,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/fields"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/klog"
 	"k8s.io/klog/klogr"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -72,6 +74,24 @@ func (l *labelFlags) Set(value string) error {
 	}
 }
 
+func setupflags() {
+	klog.InitFlags(nil)
+
+	flag.StringVar(&namespace, "namespace", "default", "Namespace in the management cluster where you would like to register this host")
+	flag.Var(&labels, "label", "labels to attach to the ByoHost CR in the form labelname=labelVal for e.g. '--label site=apac --label cores=2'")
+	flag.StringVar(&metricsbindaddress, "metricsbindaddress", ":8080", "metricsbindaddress is the TCP address that the controller should bind to for serving prometheus metrics.It can be set to \"0\" to disable the metrics serving")
+	flag.StringVar(&downloadpath, "downloadpath", "/var/lib/byoh/bundles", "File System path to keep the downloads")
+	flag.BoolVar(&skipInstallation, "skip-installation", false, "If you want to skip installation of the kubernetes component binaries")
+	flag.BoolVar(&printVersion, "version", false, "Print the version of the agent")
+
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+	hiddenFlags := [] string{"log-flush-frequency", "alsologtostderr", "log-backtrace-at", "log-dir", "logtostderr", "stderrthreshold", "vmodule", "azure-container-registry-config",
+							 "log_backtrace_at", "log_dir", "log_file", "log_file_max_size", "add_dir_header", "skip_headers", "skip_log_headers"}
+	for _, hiddenFlag := range hiddenFlags {
+		_ = pflag.CommandLine.MarkHidden(hiddenFlag)
+	}
+}
+
 var (
 	namespace          string
 	scheme             *runtime.Scheme
@@ -86,13 +106,8 @@ var (
 // TODO - fix logging
 
 func main() {
-	flag.StringVar(&namespace, "namespace", "default", "Namespace in the management cluster where you would like to register this host")
-	flag.Var(&labels, "label", "labels to attach to the ByoHost CR in the form labelname=labelVal for e.g. '--label site=apac --label cores=2'")
-	flag.StringVar(&metricsbindaddress, "metricsbindaddress", ":8080", "metricsbindaddress is the TCP address that the controller should bind to for serving prometheus metrics.It can be set to \"0\" to disable the metrics serving")
-	flag.StringVar(&downloadpath, "downloadpath", "/var/lib/byoh/bundles", "File System path to keep the downloads")
-	flag.BoolVar(&skipInstallation, "skip-installation", false, "If you want to skip installation of the kubernetes component binaries")
-	flag.BoolVar(&printVersion, "version", false, "Print the version of the agent")
-	flag.Parse()
+	setupflags()
+	pflag.Parse()
 
 	if printVersion {
 		info := version.Get()
@@ -155,7 +170,8 @@ func main() {
 		k8sInstaller = nil
 		logger.Info("skip-installation flag set, skipping installer initialisation")
 	} else {
-		k8sInstaller, err = installer.New(downloadpath, logger)
+		// increasing installer log level to 1, so that it wont be logged by default
+		k8sInstaller, err = installer.New(downloadpath, logger.V(1))
 		if err != nil {
 			logger.Error(err, "failed to instantiate installer")
 		}

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/onsi/gomega v1.18.1
 	github.com/opencontainers/runc v1.0.3 // indirect
 	github.com/pkg/errors v0.9.1
+	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/theupdateframework/notary v0.7.0 // indirect
 	k8s.io/api v0.22.2
 	k8s.io/apimachinery v0.22.2