refact(deps): bump k8s and client-go deps to version v0.20.2 (#294)

Signed-off-by: prateekpandey14 <prateek.pandey@mayadata.io>

vendor/cloud.google.com/go/compute/metadata/metadata.go

@@ -61,25 +61,14 @@ var (
 	instID  = &cachedValue{k: "instance/id", trim: true}
 )
 
-var (
-	defaultClient = &Client{hc: &http.Client{
-		Transport: &http.Transport{
-			Dial: (&net.Dialer{
-				Timeout:   2 * time.Second,
-				KeepAlive: 30 * time.Second,
-			}).Dial,
-			ResponseHeaderTimeout: 2 * time.Second,
-		},
-	}}
-	subscribeClient = &Client{hc: &http.Client{
-		Transport: &http.Transport{
-			Dial: (&net.Dialer{
-				Timeout:   2 * time.Second,
-				KeepAlive: 30 * time.Second,
-			}).Dial,
-		},
-	}}
-)
+var defaultClient = &Client{hc: &http.Client{
+	Transport: &http.Transport{
+		Dial: (&net.Dialer{
+			Timeout:   2 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).Dial,
+	},
+}}
 
 // NotDefinedError is returned when requested metadata is not defined.
 //
@@ -206,10 +195,9 @@ func systemInfoSuggestsGCE() bool {
 	return name == "Google" || name == "Google Compute Engine"
 }
 
-// Subscribe calls Client.Subscribe on a client designed for subscribing (one with no
-// ResponseHeaderTimeout).
+// Subscribe calls Client.Subscribe on the default client.
 func Subscribe(suffix string, fn func(v string, ok bool) error) error {
-	return subscribeClient.Subscribe(suffix, fn)
+	return defaultClient.Subscribe(suffix, fn)
 }
 
 // Get calls Client.Get on the default client.
@@ -280,9 +268,14 @@ type Client struct {
 	hc *http.Client
 }
 
-// NewClient returns a Client that can be used to fetch metadata. All HTTP requests
-// will use the given http.Client instead of the default client.
+// NewClient returns a Client that can be used to fetch metadata.
+// Returns the client that uses the specified http.Client for HTTP requests.
+// If nil is specified, returns the default client.
 func NewClient(c *http.Client) *Client {
+	if c == nil {
+		return defaultClient
+	}
+
 	return &Client{hc: c}
 }
 
@@ -304,7 +297,10 @@ func (c *Client) getETag(suffix string) (value, etag string, err error) {
 		host = metadataIP
 	}
 	u := "http://" + host + "/computeMetadata/v1/" + suffix
-	req, _ := http.NewRequest("GET", u, nil)
+	req, err := http.NewRequest("GET", u, nil)
+	if err != nil {
+		return "", "", err
+	}
 	req.Header.Set("Metadata-Flavor", "Google")
 	req.Header.Set("User-Agent", userAgent)
 	res, err := c.hc.Do(req)
@@ -407,11 +403,7 @@ func (c *Client) InstanceTags() ([]string, error) {
 
 // InstanceName returns the current VM's instance ID string.
 func (c *Client) InstanceName() (string, error) {
-	host, err := c.Hostname()
-	if err != nil {
-		return "", err
-	}
-	return strings.Split(host, ".")[0], nil
+	return c.getTrimmed("instance/name")
 }
 
 // Zone returns the current VM's zone, such as "us-central1-b".