Add capability to set timeout for ec2metadata's http client

aws/config.go

@@ -189,6 +189,11 @@ type Config struct {
 	//
 	EC2MetadataDisableTimeoutOverride *bool
 
+	// Set this to override duration of the EC2Metadata client
+	// This is helpful if you want to have different timout value between
+	// custom HTTP client and ec2metadata client
+	EC2MetadataTimeout *time.Duration
+
 	// Instructs the endpoint to be generated for a service client to
 	// be the dual stack endpoint. The dual stack endpoint will support
 	// both IPv4 and IPv6 addressing.
@@ -429,6 +434,13 @@ func (c *Config) WithEC2MetadataDisableTimeoutOverride(enable bool) *Config {
 	return c
 }
 
+// WithEC2MetadataTimeout sets a config EC2MetadataTimeout value
+// returning a Config pointer for chaining.
+func (c *Config) WithEC2MetadataTimeout(timeout time.Duration) *Config {
+	c.EC2MetadataTimeout = &timeout
+	return c
+}
+
 // WithSleepDelay overrides the function used to sleep while waiting for the
 // next retry. Defaults to time.Sleep.
 func (c *Config) WithSleepDelay(fn func(time.Duration)) *Config {
@@ -573,6 +585,10 @@ func mergeInConfig(dst *Config, other *Config) {
 		dst.EC2MetadataDisableTimeoutOverride = other.EC2MetadataDisableTimeoutOverride
 	}
 
+	if other.EC2MetadataTimeout != nil {
+		dst.EC2MetadataTimeout = other.EC2MetadataTimeout
+	}
+
 	if other.SleepDelay != nil {
 		dst.SleepDelay = other.SleepDelay
 	}

aws/ec2metadata/service.go

@@ -81,13 +81,18 @@ func New(p client.ConfigProvider, cfgs ...*aws.Config) *EC2Metadata {
 // To disable this set Config.EC2MetadataDisableTimeoutOverride to false. Enabled by default.
 func NewClient(cfg aws.Config, handlers request.Handlers, endpoint, signingRegion string, opts ...func(*client.Client)) *EC2Metadata {
 	if !aws.BoolValue(cfg.EC2MetadataDisableTimeoutOverride) && httpClientZero(cfg.HTTPClient) {
+		timeout := 1 * time.Second
+		if cfg.EC2MetadataTimeout != nil {
+			timeout = *cfg.EC2MetadataTimeout
+		}
+
 		// If the http client is unmodified and this feature is not disabled
 		// set custom timeouts for EC2Metadata requests.
 		cfg.HTTPClient = &http.Client{
 			// use a shorter timeout than default because the metadata
 			// service is local if it is running, and to fail faster
 			// if not running on an ec2 instance.
-			Timeout: 1 * time.Second,
+			Timeout: timeout,
 		}
 		// max number of retries on the client operation
 		cfg.MaxRetries = aws.Int(2)

aws/ec2metadata/service_test.go

@@ -53,6 +53,15 @@ func TestClientNotOverrideDefaultHTTPClientTimeout(t *testing.T) {
 	}
 }
 
+func TestClientHTTPClientTimeout(t *testing.T) {
+	cfg := aws.NewConfig().WithEC2MetadataTimeout(time.Second * 5)
+	svc := ec2metadata.New(unit.Session, cfg)
+
+	if e, a := *cfg.EC2MetadataTimeout, *svc.Config.EC2MetadataTimeout; e != a {
+		t.Errorf("expect %v, got %v", e, a)
+	}
+}
+
 func TestClientDisableOverrideDefaultHTTPClientTimeout(t *testing.T) {
 	svc := ec2metadata.New(unit.Session, aws.NewConfig().WithEC2MetadataDisableTimeoutOverride(true))