helpers: handle non numeric kernel versions (#345)

Some kernels report their version with non numeric characters such as +.
Handle these cases in kernel version comparisons.

helpers/common.go

@@ -6,6 +6,7 @@ import (
  "strconv"
  "strings"
  "syscall"
+ "unicode"
 )
 
 func checkEnvPath(env string) (string, error) {
@@ -88,6 +89,7 @@ const (
 // 4.18.0-305.7.1.el8_4.centos.x86_64 (centos)
 // 4.18.0-305.7.1.el8_4.centos.plus.x86_64 (centos + plus repo)
 // 5.13.13-arch1-1 (archlinux)
+// 5.4.228+ (ubuntu-gke 5.4)
 func CompareKernelRelease(base, given string) (KernelVersionComparison, error) {
  b := strings.Split(base, "-") // [base]-xxx
  b = strings.Split(b[0], ".") // [major][minor][patch]
@@ -108,11 +110,11 @@ func CompareKernelRelease(base, given string) (KernelVersionComparison, error) {
  }
 
  for n := 0; n <= 2; n++ {
- givenValue, err := strconv.Atoi(g[n])
+ givenValue, err := strconv.Atoi(cleanVersionNumber(g[n]))
  if err != nil {
  return KernelVersionInvalid, fmt.Errorf("invalid given kernel version value: %s issue with: %s", given, g[n])
  }
- baseValue, err := strconv.Atoi(b[n])
+ baseValue, err := strconv.Atoi(cleanVersionNumber(b[n]))
  if err != nil {
  return KernelVersionInvalid, fmt.Errorf("invalid base kernel version value: %s issue with: %s", base, b[n])
  }
@@ -127,3 +129,12 @@ func CompareKernelRelease(base, given string) (KernelVersionComparison, error) {
  }
  return KernelVersionEqual, nil
 }
+
+func cleanVersionNumber(number string) string {
+ return strings.Map(func(r rune) rune {
+ if unicode.IsDigit(r) {
+ return r
+ }
+ return -1
+ }, number)
+}

helpers/common_test.go

@@ -22,6 +22,18 @@ func TestCompareKernelRelease(t *testing.T) {
  expectedComparison: KernelVersionOlder,
  expectedError: nil,
  },
+ {
+ testName: "valid with +, older than",
+ base: "5.4.228+",
+ given: "4.18",
+ expectedComparison: KernelVersionOlder,
+ },
+ {
+ testName: "valid with alphabet, older than",
+ base: "5.6b",
+ given: "4.18",
+ expectedComparison: KernelVersionOlder,
+ },
  {
  testName: "equal",
  base: "5.0",