refactor: log gathering

pkg/gatherers/clusterconfig/gather_kube_controller_manager_logs_test.go

@@ -51,8 +51,7 @@ func Test_GatherKubeControllerManagerLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithRegexFilter(messagesRegex),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_node_logs.go

@@ -123,7 +123,7 @@ func nodeLogString(ctx context.Context, req *rest.Request, messagesRegex *regexp
 		scanner = bufio.NewScanner(r)
 	}
 
-	return common.FilterLogFromScanner(scanner, nil, messagesRegex, func(lines []string) []string {
+	return common.FilterLogFromScanner(scanner, common.WithRegexFilter(messagesRegex), func(lines []string) []string {
 		if len(lines) > logNodeMaxLines {
 			return lines[len(lines)-logNodeMaxLines:]
 		}

pkg/gatherers/clusterconfig/gather_openshift_apiserver_operator_logs_test.go

@@ -2,7 +2,6 @@ package clusterconfig
 
 import (
 	"bufio"
-	"regexp"
 	"strings"
 	"testing"
 
@@ -36,10 +35,6 @@ func Test_GatherOpenShiftAPIServerOperatorLogs(t *testing.T) {
 
 	// Given
 	msgFilter := getAPIServerOperatorLogsMessagesFilter()
-	var messagesRegex *regexp.Regexp
-	if msgFilter.IsRegexSearch {
-		messagesRegex = regexp.MustCompile(strings.Join(msgFilter.MessagesToSearch, "|"))
-	}
 
 	for _, testCase := range testCases {
 		tc := testCase
@@ -51,8 +46,7 @@ func Test_GatherOpenShiftAPIServerOperatorLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithSubstringFilter(msgFilter.MessagesToSearch),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_openshift_authentication_logs_test.go

@@ -2,7 +2,6 @@ package clusterconfig
 
 import (
 	"bufio"
-	"regexp"
 	"strings"
 	"testing"
 
@@ -31,10 +30,6 @@ func Test_GatherOpenshiftAuthenticationLogs(t *testing.T) {
 
 	// Given
 	msgFilter := getOpenshiftAuthenticationLogsMessagesFilter()
-	var messagesRegex *regexp.Regexp
-	if msgFilter.IsRegexSearch {
-		messagesRegex = regexp.MustCompile(strings.Join(msgFilter.MessagesToSearch, "|"))
-	}
 
 	for _, testCase := range testCases {
 		tc := testCase
@@ -46,8 +41,7 @@ func Test_GatherOpenshiftAuthenticationLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithSubstringFilter(msgFilter.MessagesToSearch),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_openshift_sdn_controller_logs_test.go

@@ -61,8 +61,7 @@ func Test_GatherOpenshiftSDNControllerLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithRegexFilter(messagesRegex),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_openshift_sdn_logs_test.go

@@ -2,7 +2,6 @@ package clusterconfig
 
 import (
 	"bufio"
-	"regexp"
 	"strings"
 	"testing"
 
@@ -46,10 +45,6 @@ func Test_GatherOpenshiftSDNLogs(t *testing.T) {
 
 	// Given
 	msgFilter := getGatherOpenshiftSDNLogsMessageFilter()
-	var messagesRegex *regexp.Regexp
-	if msgFilter.IsRegexSearch {
-		messagesRegex = regexp.MustCompile(strings.Join(msgFilter.MessagesToSearch, "|"))
-	}
 
 	for _, testCase := range testCases {
 		tc := testCase
@@ -61,8 +56,7 @@ func Test_GatherOpenshiftSDNLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithSubstringFilter(msgFilter.MessagesToSearch),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_sap_vsystem_iptables_logs_test.go

@@ -2,7 +2,6 @@ package clusterconfig
 
 import (
 	"bufio"
-	"regexp"
 	"strings"
 	"testing"
 
@@ -31,10 +30,6 @@ func Test_GatherSAPVsystemIptablesLogs(t *testing.T) {
 
 	// Given
 	msgFilter := getSAPLicenseManagementLogsMessageFilter()
-	var messagesRegex *regexp.Regexp
-	if msgFilter.IsRegexSearch {
-		messagesRegex = regexp.MustCompile(strings.Join(msgFilter.MessagesToSearch, "|"))
-	}
 
 	for _, testCase := range testCases {
 		tc := testCase
@@ -46,8 +41,7 @@ func Test_GatherSAPVsystemIptablesLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithSubstringFilter(msgFilter.MessagesToSearch),
 				nil)
 
 			// Assert

pkg/gatherers/clusterconfig/gather_scheduler_logs_test.go

@@ -2,7 +2,6 @@ package clusterconfig
 
 import (
 	"bufio"
-	"regexp"
 	"strings"
 	"testing"
 
@@ -31,10 +30,6 @@ func Test_GatherSchedulerLogs(t *testing.T) {
 
 	// Given
 	msgFilter := getSchedulerLogsMessagesFilter()
-	var messagesRegex *regexp.Regexp
-	if msgFilter.IsRegexSearch {
-		messagesRegex = regexp.MustCompile(strings.Join(msgFilter.MessagesToSearch, "|"))
-	}
 
 	for _, testCase := range testCases {
 		tc := testCase
@@ -46,8 +41,7 @@ func Test_GatherSchedulerLogs(t *testing.T) {
 				bufio.NewScanner(strings.NewReader(
 					tc.logline,
 				)),
-				msgFilter.MessagesToSearch,
-				messagesRegex,
+				common.WithSubstringFilter(msgFilter.MessagesToSearch),
 				nil)
 
 			// Assert

pkg/gatherers/common/gather_logs.go

@@ -37,6 +37,12 @@ type LogMessagesFilter struct {
 	Previous         bool     `json:"previous,omitempty"`
 }
 
+// FilterLogCallbackFunc is used to apply extra filtering to log lines
+type FilterLogCallbackFunc func(lines []string) []string
+
+// FilterLogOption is used to apply the filter engine (e.g: Regex, Substring)
+type FilterLogOption func(line string) bool
+
 // CollectLogsFromContainers collects logs from containers
 //   - containerFilter allows you to specify
 //   - namespace in which to search for pods
@@ -125,7 +131,14 @@ func CollectLogsFromContainers( //nolint:gocyclo
 
 			request := coreClient.Pods(containersFilter.Namespace).GetLogs(pod.Name, podLogOptions(containerName, messagesFilter))
 
-			logs, err := filterLogs(ctx, request, messagesFilter.MessagesToSearch, messagesRegexp)
+			var filter FilterLogOption
+			if messagesFilter.IsRegexSearch {
+				filter = WithRegexFilter(messagesRegexp)
+			} else {
+				filter = WithSubstringFilter(messagesFilter.MessagesToSearch)
+			}
+
+			logs, err := FilterLogsFromRequest(ctx, request, filter)
 			if err != nil {
 				return nil, err
 			}
@@ -162,9 +175,32 @@ func podContainers(pod *corev1.Pod) []string {
 	return containerNames
 }
 
-func filterLogs(
-	ctx context.Context, request *restclient.Request, messagesToSearch []string, messagesRegexp *regexp.Regexp,
-) (string, error) {
+// WithRegexFilter filter the log line with the given regex
+func WithRegexFilter(r *regexp.Regexp) FilterLogOption {
+	return func(line string) bool {
+		return r.MatchString(line)
+	}
+}
+
+// WithSubstringFilter filter the log line with the given messages
+func WithSubstringFilter(messages []string) FilterLogOption {
+	return func(line string) bool {
+		if len(messages) == 0 {
+			return true
+		}
+
+		for _, m := range messages {
+			if strings.Contains(strings.ToLower(line), strings.ToLower(m)) {
+				return true
+			}
+		}
+		return false
+	}
+}
+
+// FilterLogsFromRequest filters the desired messages from log from given Request.
+// If no filter is specified all log lines in the request would be included.
+func FilterLogsFromRequest(ctx context.Context, request *restclient.Request, filter FilterLogOption) (string, error) {
 	stream, err := request.Stream(ctx)
 	if err != nil {
 		return "", err
@@ -178,34 +214,23 @@ func filterLogs(
 	}()
 
 	scanner := bufio.NewScanner(stream)
-	return FilterLogFromScanner(scanner, messagesToSearch, messagesRegexp, nil)
+	return FilterLogFromScanner(scanner, filter, nil)
 }
 
-// FilterLogFromScanner filters the desired messages from the log
-func FilterLogFromScanner(scanner *bufio.Scanner, messagesToSearch []string, messagesRegexp *regexp.Regexp,
-	cb func(lines []string) []string) (string, error) {
+// FilterLogFromScanner filters the desired messages from the log from given Scanner.
+// If no filter is specified all log lines in the scanner would be included.
+func FilterLogFromScanner(scanner *bufio.Scanner, filter FilterLogOption, cb FilterLogCallbackFunc,
+) (string, error) {
 	var result []string
 
 	for scanner.Scan() {
 		line := scanner.Text()
-
-		if messagesRegexp != nil {
-			matches := messagesRegexp.MatchString(line)
-			if matches {
-				result = append(result, line)
-			}
-			continue
-		}
-
-		for _, messageToSearch := range messagesToSearch {
-			if strings.Contains(strings.ToLower(line), strings.ToLower(messageToSearch)) {
-				result = append(result, line)
-			}
+		if filter == nil {
+			result = append(result, line)
 		}
 
-		if len(messagesToSearch) == 0 {
+		if ok := filter(line); ok {
 			result = append(result, line)
-			continue
 		}
 	}
 

pkg/gatherers/common/gather_logs_test.go

@@ -172,7 +172,13 @@ func Test_FilterLogFromScanner(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			reader := strings.NewReader(testText)
-			result, err := FilterLogFromScanner(bufio.NewScanner(reader), tt.messagesToSearch, tt.messagesRegex, nil)
+			var filter FilterLogOption
+			if tt.messagesRegex != nil {
+				filter = WithRegexFilter(tt.messagesRegex)
+			} else {
+				filter = WithSubstringFilter(tt.messagesToSearch)
+			}
+			result, err := FilterLogFromScanner(bufio.NewScanner(reader), filter, nil)
 			assert.NoError(t, err)
 			assert.Equal(t, tt.expectedOutput, result)
 		})
@@ -186,7 +192,7 @@ func Benchmark_FilterLogFromScanner(b *testing.B) {
 	reader := strings.NewReader(testText)
 	for i := 0; i <= b.N; i++ {
 		// nolint errcheck
-		FilterLogFromScanner(bufio.NewScanner(reader), messagesToSearch, messagesRegex, nil)
+		FilterLogFromScanner(bufio.NewScanner(reader), WithRegexFilter(messagesRegex), nil)
 		runtime.ReadMemStats(&m)
 		b.Logf("Size of allocated heap objects: %d MB, Size of heap in use: %d MB", m.Alloc/1024/1024, m.HeapInuse/1024/1024)
 	}