feat: Allow checking kernel versions only in host os analyzer (#1585)

* Allow checking kernel versions only in host os analyzer

Signed-off-by: Evans Mungai <evans@replicated.com>

* Minor fix in logic

Signed-off-by: Evans Mungai <evans@replicated.com>

* Fix formatting

Signed-off-by: Evans Mungai <evans@replicated.com>

---------

Signed-off-by: Evans Mungai <evans@replicated.com>

pkg/analyze/host_os_info.go

@@ -86,19 +86,36 @@ func analyzeOSVersionResult(osInfo collect.HostOSInfo, outcomes []*troubleshootv
 		}
 
 		parts := strings.Split(when, " ")
-		platform := parts[0]
+		if len(parts) < 3 {
+			return []*AnalyzeResult{&result}, errors.New("when condition must have at least 3 parts")
+		}
 		expectedVer := fixVersion(parts[2])
 		toleratedVer, err := semver.ParseTolerant(expectedVer)
 		if err != nil {
-			return []*AnalyzeResult{&result}, errors.Wrapf(err, "failed to parse tolerant: %s", expectedVer)
+			return []*AnalyzeResult{&result}, errors.Wrapf(err, "failed to parse version: %s", expectedVer)
 		}
-
 		when = fmt.Sprintf("%s %v", parts[1], toleratedVer)
 		whenRange, err := semver.ParseRange(when)
 		if err != nil {
-			return []*AnalyzeResult{&result}, errors.Wrapf(err, "failed to parse range: %s", when)
+			return []*AnalyzeResult{&result}, errors.Wrapf(err, "failed to parse version range: %s", when)
 		}
 
+		// Match the kernel version regardless of the platform
+		// e.g "kernelVersion == 4.15"
+		if parts[0] == "kernelVersion" {
+			fixedKernelVer := fixVersion(osInfo.KernelVersion)
+			toleratedKernelVer, err := semver.ParseTolerant(fixedKernelVer)
+			if err != nil {
+				return []*AnalyzeResult{}, errors.Wrapf(err, "failed to parse tolerant: %v", fixedKernelVer)
+			}
+			if whenRange(toleratedKernelVer) {
+				return []*AnalyzeResult{&result}, nil
+			}
+		}
+
+		// Match the platform version and and kernel version passed in as
+		// "<platform>-<kernelVersion>-kernel" e.g "centos-8.2-kernel == 8.2"
+		platform := parts[0]
 		kernelInfo := fmt.Sprintf("%s-%s-kernel", osInfo.Platform, osInfo.PlatformVersion)
 		if len(strings.Split(platform, "-")) == 3 && strings.Split(platform, "-")[2] == "kernel" {
 			if platform == kernelInfo {
@@ -111,6 +128,8 @@ func analyzeOSVersionResult(osInfo collect.HostOSInfo, outcomes []*troubleshootv
 					return []*AnalyzeResult{&result}, nil
 				}
 			}
+			// Match the platform version
+			// e.g "centos == 8.2"
 		} else if platform == osInfo.Platform {
 			fixedDistVer := fixVersion(osInfo.PlatformVersion)
 			toleratedDistVer, err := semver.ParseTolerant(fixedDistVer)

pkg/analyze/host_os_info_test.go

@@ -319,6 +319,34 @@ func TestAnalyzeHostOS(t *testing.T) {
 				},
 			},
 		},
+
+		{
+			name: "test kernelVersion >= 6.4.9-abc",
+			hostInfo: collect.HostOSInfo{
+				Name:            "my-host",
+				KernelVersion:   "6.5.0-1024-gcp",
+				PlatformVersion: "22.04",
+				Platform:        "ubuntu",
+			},
+			hostAnalyzer: &troubleshootv1beta2.HostOSAnalyze{
+				Outcomes: []*troubleshootv1beta2.Outcome{
+					{
+						Pass: &troubleshootv1beta2.SingleOutcome{
+							When:    "kernelVersion >= 6.4.9-abc",
+							Message: "supported kernel version >= 6.4.9-abc",
+						},
+					},
+				},
+			},
+
+			result: []*AnalyzeResult{
+				{
+					Title:   "Host OS Info",
+					IsPass:  true,
+					Message: "supported kernel version >= 6.4.9-abc",
+				},
+			},
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {