ACM-15078: Created new function extractCmdlineParams and updated unit…

… test case for the same

Signed-off-by: DAMISETTI-VEERABHADRARAO <[email protected]>

src/commands/actions/reboot_for_reclaim.go

@@ -32,7 +32,6 @@ func (a *rebootForReclaim) Run() (stdout, stderr string, exitCode int) {
 
 	if runtime.GOARCH == "s390x" {
 		var options string
-		cmdline_params := make(map[string]string)
 		var requiredCmdline string
 
 		stdout, stderr, exitCode = util.Execute("cat", "/boot/loader/entries/00-assisted-discovery.conf")
@@ -61,17 +60,7 @@ func (a *rebootForReclaim) Run() (stdout, stderr string, exitCode int) {
 			"rd.dasd",
 		}
 
-		for _, param := range paramsToExtract {
-			regex := regexp.MustCompile(fmt.Sprintf(`\b%s=([^\s]+)`, param))
-			match := regex.FindStringSubmatch(stdout)
-			if len(match) > 1 {
-				cmdline_params[param] = match[1]
-			}
-		}
-
-		for key, value := range cmdline_params {
-			requiredCmdline += fmt.Sprintf("%s=%s ", key, value)
-		}
+		requiredCmdline = extractCmdlineParams(stdout, paramsToExtract)
 
 		unshareCommand := "unshare"
 		unshareArgs := []string{
@@ -93,6 +82,30 @@ func (a *rebootForReclaim) Run() (stdout, stderr string, exitCode int) {
 	return util.Execute("systemctl", "reboot")
 }
 
+// Returns the paramsToExtract parameters which are present in cmdlineOutput, if no paramter matched then returns any empty string ''
+
+func extractCmdlineParams(cmdlineOutput string, paramsToExtract []string) string {
+	cmdlineParams := make(map[string]string)
+	var requiredCmdline string
+
+	// Matches the exact param from paramsToExtract followed by an = sign, and then capture the non-whitespace value after the =
+	for _, param := range paramsToExtract {
+		regex := regexp.MustCompile(fmt.Sprintf(`\b%s=([^\s]+)`, param))
+		match := regex.FindStringSubmatch(cmdlineOutput)
+		if len(match) > 1 {
+			cmdlineParams[param] = match[1]
+		}
+	}
+
+	// Convert the key value pairs in map to string with predefined order which is in paramsToExtract
+	for _, key := range paramsToExtract {
+		if value, exists := cmdlineParams[key]; exists {
+			requiredCmdline += fmt.Sprintf("%s=%s ", key, value)
+		}
+	}
+	return requiredCmdline
+}
+
 // Unused, but required as part of ActionInterface
 func (a *rebootForReclaim) Command() string {
 	return "systemctl"

src/commands/actions/reboot_for_reclaim_test.go

@@ -21,4 +21,25 @@ var _ = Describe("reboot_for_reclaim", func() {
 	It("fails when given bad input", func() {
 		badParamsCommonTests(models.StepTypeRebootForReclaim, []string{})
 	})
+
+	Context("extractCmdlineParams", func() {
+		It("returns the expected parameters when valid cmdline output is given", func() {
+			cmdlineOutput := "ip=192.168.1.1 nameserver=8.8.8.8 rd.znet=enabled zfcp.allow_lun_scan=0 rd.zfcp=xyz rd.dasd=abc"
+			paramsToExtract := []string{"ip", "nameserver", "rd.znet", "zfcp.allow_lun_scan", "rd.zfcp", "rd.dasd"}
+
+			expectedCmdline := "ip=192.168.1.1 nameserver=8.8.8.8 rd.znet=enabled zfcp.allow_lun_scan=0 rd.zfcp=xyz rd.dasd=abc "
+			requiredCmdline := extractCmdlineParams(cmdlineOutput, paramsToExtract)
+
+			Expect(requiredCmdline).To(Equal(expectedCmdline))
+		})
+
+		It("returns an empty string when no parameters match", func() {
+			cmdlineOutput := "other_param=value"
+			paramsToExtract := []string{"ip", "nameserver"}
+
+			requiredCmdline := extractCmdlineParams(cmdlineOutput, paramsToExtract)
+
+			Expect(requiredCmdline).To(Equal(""))
+		})
+	})
 })