ddtrace/tracer: Add WithLogStartup startup option

ddtrace/tracer/option.go

@@ -473,6 +473,13 @@ func WithHostname(name string) StartOption {
 	}
 }
 
+// WithLogStartup allows control over whether to print the startup log or not
+func WithLogStartup(enabled bool) StartOption {
+	return func(c *config) {
+		c.logStartup = enabled
+	}
+}
+
 // StartSpanOption is a configuration option for StartSpan. It is aliased in order
 // to help godoc group all the functions returning it together. It is considered
 // more correct to refer to it as the type as the origin, ddtrace.StartSpanOption.

ddtrace/tracer/option_test.go

@@ -498,3 +498,12 @@ func TestWithHostname(t *testing.T) {
 		assert.Equal("hostname-middleware", c.hostname)
 	})
 }
+
+func TestWithLogStartup(t *testing.T) {
+	c := newConfig()
+	assert.True(t, c.logStartup)
+	WithLogStartup(false)(c)
+	assert.False(t, c.logStartup)
+	WithLogStartup(true)(c)
+	assert.True(t, c.logStartup)
+}