feat(http): Add a Helm user-agent string to the http getter

Adding a user-agent to the http getter will enable servers to
distinguish between helm (including various versions) and other
tools connecting to the server.

Author: mattfarina

pkg/getter/httpgetter.go

@@ -20,9 +20,11 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"strings"
 
 	"k8s.io/helm/pkg/tlsutil"
 	"k8s.io/helm/pkg/urlutil"
+	"k8s.io/helm/pkg/version"
 )
 
 //httpGetter is the efault HTTP(/S) backend handler
@@ -34,7 +36,15 @@ type httpGetter struct {
 func (g *httpGetter) Get(href string) (*bytes.Buffer, error) {
 	buf := bytes.NewBuffer(nil)
 
-	resp, err := g.client.Get(href)
+	// Set a helm specific user agent so that a repo server and metrics can
+	// separate helm calls from other tools interacting with repos.
+	req, err := http.NewRequest("GET", href, nil)
+	if err != nil {
+		return buf, err
+	}
+	req.Header.Set("User-Agent", "Helm/"+strings.TrimPrefix(version.GetVersion(), "v"))
+
+	resp, err := g.client.Do(req)
 	if err != nil {
 		return buf, err
 	}