Added documentation for alpha cli command (#4412)

Added comments to document several methods and strucs on cmd package. Based on GoDoc guidelines. Focus on alpha cli command

Signed-off-by: arthursens <arthursens2005@gmail.com>

cli/cmd/alpha.go

@@ -4,6 +4,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// newCmdAlpha creates a new cobra command `alpha` which contains experimental subcommands for linkerd
 func newCmdAlpha() *cobra.Command {
 	alphaCmd := &cobra.Command{
 		Use:   "alpha",

cli/cmd/alpha_clients.go

@@ -12,10 +12,15 @@ import (
 	corev1 "k8s.io/api/core/v1"
 )
 
+// alphaClientsOptions holds values for command line flags that apply to the alpha
+// clients command. All fields in this struct should have corresponding flags added in
+// the newCmdAlphaClients func later in this file.
 type alphaClientsOptions struct {
 	namespace string
 }
 
+// newCmdAlphaClients creates a new cobra command for the `alpha clients` subcommand which
+// display client-side traffic stats to a resource. [Experimental]
 func newCmdAlphaClients() *cobra.Command {
 	options := alphaClientsOptions{
 		namespace: corev1.NamespaceDefault,

cli/cmd/alpha_stat.go

@@ -30,12 +30,17 @@ var allowedKinds = map[string]struct{}{
 	k8s.StatefulSet:           struct{}{},
 }
 
+// alphaStatOptions holds values for command line flags that apply to the alpha
+// stat command. All fields in this struct should have corresponding flags added in
+// the newCmdAlphaStat func later in this file.
 type alphaStatOptions struct {
 	namespace     string
 	toResource    string
 	allNamespaces bool
 }
 
+// newCmdAlphaStat creates a new cobra command for the `alpha stat` subcommand which
+// display traffic stats about one or many resources. [Experimental]
 func newCmdAlphaStat() *cobra.Command {
 	options := alphaStatOptions{
 		namespace: "default",
@@ -176,6 +181,8 @@ func renderTrafficMetricsList(metrics *v1alpha1.TrafficMetricsList, allNamespace
 	t.Render(w)
 }
 
+// renderTrafficMetricsEdgesList will render a table to the given Writer.
+// Rows will be filtered to make sure that only traffic directed to the resource requested by the `--to` flag is shown
 func renderTrafficMetricsEdgesList(metrics *v1alpha1.TrafficMetricsList, w io.Writer, toResource *public.Resource, direction string) {
 	t := buildTable(true, false)
 	t.Data = []table.Row{}

cli/cmd/profile.go

@@ -80,7 +80,7 @@ func newCmdProfile() *cobra.Command {
 		Short: "Output service profile config for Kubernetes",
 		Long:  "Output service profile config for Kubernetes.",
 		Example: `  # Output a basic template to apply after modification.
-  linkerd profile -n emoijvoto --template web-svc
+  linkerd profile -n emojivoto --template web-svc
 
   # Generate a profile from an OpenAPI specification.
   linkerd profile -n emojivoto --open-api web-svc.swagger web-svc