Refactored code and added unit tests

- Extracted ParseRelease method from GetKernelVersion to make code
  more testable
- Added tests for ParseRelease method

utils/utils.go

@@ -515,9 +515,7 @@ func FindCgroupMountpoint(cgroupType string) (string, error) {
 
 func GetKernelVersion() (*KernelVersionInfo, error) {
 	var (
-		flavor               string
-		kernel, major, minor int
-		err                  error
+		err error
 	)
 
 	uts, err := uname()
@@ -536,7 +534,17 @@ func GetKernelVersion() (*KernelVersionInfo, error) {
 	// Remove the \x00 from the release for Atoi to parse correctly
 	release = release[:bytes.IndexByte(release, 0)]
 
-	tmp := strings.SplitN(string(release), "-", 2)
+	return ParseRelease(string(release))
+}
+
+func ParseRelease(release string) (*KernelVersionInfo, error) {
+	var (
+		flavor               string
+		kernel, major, minor int
+		err                  error
+	)
+
+	tmp := strings.SplitN(release, "-", 2)
 	tmp2 := strings.Split(tmp[0], ".")
 
 	if len(tmp2) > 0 {

utils/utils_test.go

@@ -337,3 +337,21 @@ search dotcloud.net`: true,
 		}
 	}
 }
+
+func assertParseRelease(t *testing.T, release string, b *KernelVersionInfo, result int) {
+	var (
+		a *KernelVersionInfo
+	)
+	a, _ = ParseRelease(release)
+
+	if r := CompareKernelVersion(a, b); r != result {
+		t.Fatalf("Unexpected kernel version comparison result. Found %d, expected %d", r, result)
+	}
+}
+
+func TestParseRelease(t *testing.T) {
+	assertParseRelease(t, "3.8.0", &KernelVersionInfo{Kernel: 3, Major: 8, Minor: 0}, 0)
+	assertParseRelease(t, "3.4.54.longterm-1", &KernelVersionInfo{Kernel: 3, Major: 4, Minor: 54}, 0)
+	assertParseRelease(t, "3.4.54.longterm-1", &KernelVersionInfo{Kernel: 3, Major: 4, Minor: 54, Flavor: "1"}, 0)
+	assertParseRelease(t, "3.8.0-19-generic", &KernelVersionInfo{Kernel: 3, Major: 8, Minor: 0, Flavor: "19-generic"}, 0)
+}