Add a helper for generating Consul's user-agent string

lib/useragent.go

@@ -0,0 +1,29 @@
+package lib
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/hashicorp/consul/version"
+)
+
+var (
+	// projectURL is the project URL.
+	projectURL = "https://www.consul.io/"
+
+	// rt is the runtime - variable for tests.
+	rt = runtime.Version()
+
+	// versionFunc is the func that returns the current version. This is a
+	// function to take into account the different build processes and distinguish
+	// between enterprise and oss builds.
+	versionFunc = func() string {
+		return version.GetHumanVersion()
+	}
+)
+
+// UserAgent returns the consistent user-agent string for Consul.
+func UserAgent() string {
+	return fmt.Sprintf("Consul/%s (+%s; %s)",
+		versionFunc(), projectURL, rt)
+}

lib/useragent_test.go

@@ -0,0 +1,18 @@
+package lib
+
+import (
+	"testing"
+)
+
+func TestUserAgent(t *testing.T) {
+	projectURL = "https://consul-test.com"
+	rt = "go5.0"
+	versionFunc = func() string { return "1.2.3" }
+
+	act := UserAgent()
+
+	exp := "Consul/1.2.3 (+https://consul-test.com; go5.0)"
+	if exp != act {
+		t.Errorf("expected %q to be %q", act, exp)
+	}
+}