Release v1.3.2

debian/changelog

@@ -1,3 +1,34 @@
+ipng-router-backup (1.3.2) stable; urgency=low
+
+  * Fix --key-file authentication priority issue
+  * Prioritize explicit key file over SSH agent authentication
+
+ -- Pim van Pelt <pim@ipng.ch>  Sun, 13 Jul 2025 23:30:00 +0100
+
+ipng-router-backup (1.3.1) stable; urgency=low
+
+  * Fix golangci-lint issues, replace deprecated io/ioutil
+  * Add SSH key error messages with hostname prefix
+  * Independently validate sshkey, agent auth and password methods
+
+ -- Pim van Pelt <pim@ipng.ch>  Sun, 07 Jul 2025 23:30:00 +0100
+
+ipng-router-backup (1.3.0) stable; urgency=low
+
+  * Add --parallel flag for concurrent device processing (default: 10)
+  * Implement worker pool pattern for much faster multi-device backups
+  * Maintain atomic file operations and error handling in parallel mode
+
+ -- Pim van Pelt <pim@ipng.ch>  Sun, 07 Jul 2025 23:00:00 +0100
+
+ipng-router-backup (1.2.4) stable; urgency=low
+
+  * Add regex exclude patterns to filter unwanted output lines per device type
+  * Prefix all log messages with hostname for better multi-device visibility
+  * Add exclude pattern support for RouterOS timestamp headers
+
+ -- Pim van Pelt <pim@ipng.ch>  Sun, 07 Jul 2025 22:00:00 +0100
+
 ipng-router-backup (1.2.3) stable; urgency=low
 
   * For routeros, set mikrotik export to terse

docs/DETAILS.md

@@ -34,6 +34,14 @@ types:
       - show version
       - show inventory
       - show running-config
+
+  routeros:
+    commands:
+      - system package print detail without-paging
+      - / export terse
+    exclude:
+      - "^# ....-..-.. ..:..:.. by RouterOS"    # Filter timestamp headers
+      - "^# .../../.... ..:..:.. by RouterOS"   # Alternative date format
 ```
 
 **Main configuration** (`config.yaml`):
@@ -64,6 +72,7 @@ devices:
 #### Types Section
 - **`<type-name>`**: Device type name (e.g., `srlinux`, `eos`)
   - **`commands`**: Array of CLI commands to execute
+  - **`exclude`** (optional): Array of regex patterns to filter out unwanted lines from output
 
 #### Devices Section
 - **`<hostname>`**: Device hostname (used for SSH config lookup and output filename)
@@ -85,6 +94,43 @@ ipng-router-backup --yaml "*.yaml"
 ipng-router-backup --yaml "config/*.yaml"
 ```
 
+## Output Filtering
+
+The tool supports filtering unwanted lines from command output using regular expressions in the `exclude` field of device types.
+
+### How Exclude Patterns Work
+
+- **Regex matching**: Each line of command output is tested against all exclude patterns
+- **Line removal**: Lines matching any pattern are completely removed from the output file
+- **Per-device type**: Exclude patterns are defined at the device type level and apply to all devices of that type
+
+### Common Use Cases
+
+```yaml
+types:
+  routeros:
+    commands:
+      - / export terse
+    exclude:
+      - "^# ....-..-.. ..:..:.. by RouterOS"    # Remove timestamp headers
+      - "^# .../../.... ..:..:.. by RouterOS"   # Alternative date format
+
+  cisco-ios:
+    commands:
+      - show running-config
+    exclude:
+      - "^Building configuration"               # Remove config build messages
+      - "^Current configuration"                # Remove current config headers
+      - "^!"                                   # Remove comment lines
+
+  debug-device:
+    commands:
+      - show logs
+    exclude:
+      - "^DEBUG:"                             # Filter debug messages
+      - "^TRACE:"                             # Filter trace messages
+```
+
 ## Command Line Usage
 
 ### Required Flags
@@ -96,6 +142,7 @@ ipng-router-backup --yaml "config/*.yaml"
 - **`--password`**: SSH password
 - **`--key-file`**: SSH private key file path
 - **`--port`**: SSH port (default: `22`)
+- **`--parallel`**: Maximum number of devices to process in parallel (default: `10`)
 
 ### Examples
 
@@ -114,6 +161,9 @@ ipng-router-backup --yaml config.yaml --output-dir /backup/network
 
 # With password authentication
 ipng-router-backup --yaml config.yaml --password mypassword
+
+# Process more devices in parallel
+ipng-router-backup --yaml config.yaml --parallel 20
 ```
 
 ## SSH Authentication

docs/ipng-router-backup.1

@@ -35,6 +35,9 @@ SSH port number (default: 22)
 .BR --host " \fIHOSTNAME\fR"
 Specific host(s) or glob patterns to process (can be repeated, processes all if not specified)
 .TP
+.BR --parallel " \fINUMBER\fR"
+Maximum number of devices to process in parallel (default: 10)
+.TP
 .BR --help
 Show help message
 .SH CONFIGURATION
@@ -48,6 +51,11 @@ types:
     commands:
       - show version
       - show platform linecard
+  routeros:
+    commands:
+      - / export terse
+    exclude:
+      - "^# ....-..-.. ..:..:.. by RouterOS"
 .EE
 .SS devices
 Define individual devices:
@@ -70,6 +78,8 @@ Default SSH keys (~/.ssh/id_rsa, ~/.ssh/id_ed25519, ~/.ssh/id_ecdsa)
 Password authentication (--password option)
 .SH OUTPUT
 For each device, a text file named after the hostname is created in the specified directory. Each command output is prefixed with "## COMMAND: <command_name>" for easy identification.
+.PP
+Output can be filtered using regex patterns defined in the device type's 'exclude' field to remove unwanted lines such as timestamps or debug messages.
 .SH EXAMPLES
 .TP
 Basic usage with glob patterns:
@@ -91,6 +101,11 @@ Process hosts matching patterns:
 .EX
 ipng-router-backup --yaml config.yaml --host "asw*" --host "*switch*"
 .EE
+.TP
+Process devices in parallel:
+.EX
+ipng-router-backup --yaml config.yaml --parallel 20
+.EE
 .SH FILES
 .TP
 .I /etc/ipng-router-backup/config.yaml.example

etc/00-device-types.yaml

@@ -56,3 +56,6 @@ types:
       - system license print            # License information
       - / interface print               # Interfaces
       - / export terse                  # Configuration
+    exclude:
+      - "^# ....-..-.. ..:..:.. by RouterOS"
+      - "^# .../../.... ..:..:.. by RouterOS"

src/config.go

@@ -4,7 +4,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 
 	"dario.cat/mergo"
 	"gopkg.in/yaml.v3"
@@ -18,6 +18,7 @@ type Config struct {
 
 type DeviceType struct {
 	Commands []string `yaml:"commands"`
+	Exclude  []string `yaml:"exclude,omitempty"`
 }
 
 type Device struct {
@@ -28,7 +29,7 @@ type Device struct {
 }
 
 func readYAMLFile(path string) (map[string]interface{}, error) {
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}

src/main.go

@@ -7,19 +7,34 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"sync"
 
 	"github.com/spf13/cobra"
 )
 
-const Version = "1.2.3"
+const Version = "1.3.2"
 
-// Config and SSH types are now in separate packages
+func processDevice(hostname string, deviceConfig Device, commands []string, excludePatterns []string, password, keyFile string, port int, outputDir string) bool {
+	// Create backup instance
+	backup := NewRouterBackup(hostname, deviceConfig.Address, deviceConfig.User, password, keyFile, port)
 
-// SSH connection methods are now in ssh.go
+	// Connect and backup
+	if err := backup.Connect(); err != nil {
+		fmt.Printf("%s: Failed to connect: %v\n", hostname, err)
+		return false
+	}
 
-// YAML processing is now handled by the config package
+	err := backup.BackupCommands(commands, excludePatterns, outputDir)
+	backup.Disconnect()
 
-// SSH helper functions are now in ssh.go
+	if err != nil {
+		fmt.Printf("%s: Backup failed: %v\n", hostname, err)
+		return false
+	} else {
+		fmt.Printf("%s: Backup completed\n", hostname)
+		return true
+	}
+}
 
 func main() {
 	var yamlFiles []string
@@ -28,6 +43,7 @@ func main() {
 	var port int
 	var outputDir string
 	var hostFilter []string
+	var parallel int
 
 	var rootCmd = &cobra.Command{
 		Use:     "ipng-router-backup",
@@ -57,15 +73,27 @@ func main() {
 			}
 
 			// Check authentication setup
-			if password == "" && keyFile == "" {
-				if os.Getenv("SSH_AUTH_SOCK") != "" {
-					fmt.Println("Using SSH agent for authentication")
-				} else {
-					keyFile = findDefaultSSHKey()
-					if keyFile == "" {
-						log.Fatal("No SSH key found and no password provided")
-					}
+			hasAuth := 0
+			if os.Getenv("SSH_AUTH_SOCK") != "" {
+				fmt.Println("Using SSH agent for authentication")
+				hasAuth++
+			}
+			if keyFile == "" {
+				keyFile = findDefaultSSHKey()
+				if keyFile != "" {
+					fmt.Printf("Using SSH key: %s\n", keyFile)
+					hasAuth++
 				}
+			} else {
+				fmt.Printf("Using specified SSH key: %s\n", keyFile)
+				hasAuth++
+			}
+			if password != "" {
+				fmt.Println("Using --password for authentication")
+				hasAuth++
+			}
+			if hasAuth == 0 {
+				log.Fatal("No authentication mechanisms found.")
 			}
 
 			// Process devices
@@ -91,54 +119,88 @@ func main() {
 				}
 			}
 
-			successCount := 0
 			totalCount := len(devicesToProcess)
 
-			for hostname, deviceConfig := range devicesToProcess {
-				fmt.Printf("\nProcessing device: %s (type: %s)\n", hostname, deviceConfig.Type)
+			// Create channels for work distribution and result collection
+			type DeviceWork struct {
+				hostname        string
+				deviceConfig    Device
+				commands        []string
+				excludePatterns []string
+			}
 
+			type DeviceResult struct {
+				hostname string
+				success  bool
+			}
+
+			workChan := make(chan DeviceWork, totalCount)
+			resultChan := make(chan DeviceResult, totalCount)
+
+			// Start worker pool
+			var wg sync.WaitGroup
+			for i := 0; i < parallel; i++ {
+				wg.Add(1)
+				go func() {
+					defer wg.Done()
+					for work := range workChan {
+						fmt.Printf("%s: Processing device (type: %s)\n", work.hostname, work.deviceConfig.Type)
+
+						success := processDevice(work.hostname, work.deviceConfig, work.commands, work.excludePatterns, password, keyFile, port, outputDir)
+						resultChan <- DeviceResult{hostname: work.hostname, success: success}
+					}
+				}()
+			}
+
+			// Queue all work
+			for hostname, deviceConfig := range devicesToProcess {
 				user := deviceConfig.User
 				commands := deviceConfig.Commands
 				deviceType := deviceConfig.Type
+				var excludePatterns []string
 
-				// If device has a type, get commands from types section
+				// If device has a type, get commands and exclude patterns from types section
 				if deviceType != "" {
 					if typeConfig, exists := cfg.Types[deviceType]; exists {
 						commands = typeConfig.Commands
+						excludePatterns = typeConfig.Exclude
 					}
 				}
 
 				if user == "" {
-					fmt.Printf("No user specified for %s, skipping\n", hostname)
+					fmt.Printf("%s: No user specified, skipping\n", hostname)
 					continue
 				}
 
 				if len(commands) == 0 {
-					fmt.Printf("No commands specified for %s, skipping\n", hostname)
+					fmt.Printf("%s: No commands specified, skipping\n", hostname)
 					continue
 				}
 
-				// Create backup instance
-				backup := NewRouterBackup(hostname, deviceConfig.Address, user, password, keyFile, port)
-
-				// Connect and backup
-				if err := backup.Connect(); err != nil {
-					fmt.Printf("Failed to connect to %s: %v\n", hostname, err)
-					continue
+				workChan <- DeviceWork{
+					hostname:        hostname,
+					deviceConfig:    deviceConfig,
+					commands:        commands,
+					excludePatterns: excludePatterns,
 				}
+			}
+			close(workChan)
 
-				err = backup.BackupCommands(commands, outputDir)
-				backup.Disconnect()
+			// Wait for all workers to finish
+			go func() {
+				wg.Wait()
+				close(resultChan)
+			}()
 
-				if err != nil {
-					fmt.Printf("Backup failed for %s: %v\n", hostname, err)
-				} else {
-					fmt.Printf("Backup completed for %s\n", hostname)
+			// Collect results
+			successCount := 0
+			for result := range resultChan {
+				if result.success {
 					successCount++
 				}
 			}
 
-			fmt.Printf("\nOverall summary: %d/%d devices processed successfully\n", successCount, totalCount)
+			fmt.Printf("Overall summary: %d/%d devices processed successfully\n", successCount, totalCount)
 
 			// Set exit code based on results
 			if successCount == 0 {
@@ -156,8 +218,11 @@ func main() {
 	rootCmd.Flags().IntVar(&port, "port", 22, "SSH port")
 	rootCmd.Flags().StringVar(&outputDir, "output-dir", "/tmp", "Output directory for command output files")
 	rootCmd.Flags().StringSliceVar(&hostFilter, "host", []string{}, "Specific host(s) to process (can be repeated, processes all if not specified)")
+	rootCmd.Flags().IntVar(&parallel, "parallel", 10, "Maximum number of devices to process in parallel")
 
-	rootCmd.MarkFlagRequired("yaml")
+	if err := rootCmd.MarkFlagRequired("yaml"); err != nil {
+		log.Fatal(err)
+	}
 
 	if err := rootCmd.Execute(); err != nil {
 		log.Fatal(err)

src/ssh.go

@@ -4,10 +4,10 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -103,11 +103,6 @@ func (rb *RouterBackup) Connect() error {
 		config.KeyExchanges = finalAlgorithms
 	}
 
-	// Note: Cipher overrides disabled - Go SSH library defaults work better
-	// if ciphers := ssh_config.Get(rb.hostname, "Ciphers"); ciphers != "" {
-	//	 config.Ciphers = ...
-	// }
-
 	if macs := ssh_config.Get(rb.hostname, "MACs"); macs != "" {
 		macList := strings.Split(macs, ",")
 		for i, mac := range macList {
@@ -126,15 +121,19 @@ func (rb *RouterBackup) Connect() error {
 		config.HostKeyAlgorithms = finalAlgorithms
 	}
 
-	// Try SSH agent first if available
+	// If explicit key file is provided, prioritize it over SSH agent
+	var keyFileAuth ssh.AuthMethod
+	var agentAuth ssh.AuthMethod
+
+	// Try SSH agent if available (but don't add to config.Auth yet)
 	if sshAuthSock := os.Getenv("SSH_AUTH_SOCK"); sshAuthSock != "" {
 		if conn, err := net.Dial("unix", sshAuthSock); err == nil {
 			agentClient := agent.NewClient(conn)
-			config.Auth = []ssh.AuthMethod{ssh.PublicKeysCallback(agentClient.Signers)}
+			agentAuth = ssh.PublicKeysCallback(agentClient.Signers)
 		}
 	}
 
-	// If SSH agent didn't work, try key file
+	// Try key file
 	if keyFile != "" {
 		// Expand ~ in keyFile path
 		if strings.HasPrefix(keyFile, "~/") {
@@ -144,17 +143,27 @@ func (rb *RouterBackup) Connect() error {
 			}
 		}
 
-		key, err := ioutil.ReadFile(keyFile)
+		key, err := os.ReadFile(keyFile)
 		if err == nil {
 			signer, err := ssh.ParsePrivateKey(key)
 			if err != nil {
-				fmt.Errorf("unable to parse private key: %v", err)
+				fmt.Printf("%s: Unable to parse private key: %v\n", rb.hostname, err)
 			} else {
-				config.Auth = append(config.Auth, ssh.PublicKeys(signer))
+				keyFileAuth = ssh.PublicKeys(signer)
 			}
 		}
 	}
 
+	// Prioritize auth methods: explicit key file first, then SSH agent
+	if keyFileAuth != nil {
+		config.Auth = []ssh.AuthMethod{keyFileAuth}
+		if agentAuth != nil {
+			config.Auth = append(config.Auth, agentAuth)
+		}
+	} else if agentAuth != nil {
+		config.Auth = []ssh.AuthMethod{agentAuth}
+	}
+
 	// Fall back to password if available
 	if rb.password != "" {
 		config.Auth = append(config.Auth, ssh.Password(rb.password))
@@ -178,7 +187,7 @@ func (rb *RouterBackup) Connect() error {
 	}
 
 	rb.client = client
-	fmt.Printf("Successfully connected to %s\n", targetHost)
+	fmt.Printf("%s: Successfully connected to %s\n", rb.hostname, targetHost)
 	return nil
 }
 
@@ -202,8 +211,33 @@ func (rb *RouterBackup) RunCommand(command string) (string, error) {
 	return string(output), nil
 }
 
+// filterOutput removes lines matching exclude patterns from the output
+func filterOutput(output string, excludePatterns []string) string {
+	if len(excludePatterns) == 0 {
+		return output
+	}
+
+	lines := strings.Split(output, "\n")
+	var filteredLines []string
+
+	for _, line := range lines {
+		exclude := false
+		for _, pattern := range excludePatterns {
+			if matched, _ := regexp.MatchString(pattern, line); matched {
+				exclude = true
+				break
+			}
+		}
+		if !exclude {
+			filteredLines = append(filteredLines, line)
+		}
+	}
+
+	return strings.Join(filteredLines, "\n")
+}
+
 // BackupCommands runs multiple commands and saves outputs to files
-func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) error {
+func (rb *RouterBackup) BackupCommands(commands []string, excludePatterns []string, outputDir string) error {
 	if err := os.MkdirAll(outputDir, 0755); err != nil {
 		return fmt.Errorf("failed to create directory %s: %v", outputDir, err)
 	}
@@ -223,11 +257,11 @@ func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) erro
 	hasErrors := false
 
 	for i, command := range commands {
-		fmt.Printf("Running command %d/%d: %s\n", i+1, len(commands), command)
+		fmt.Printf("%s: Running command %d/%d: %s\n", rb.hostname, i+1, len(commands), command)
 		output, err := rb.RunCommand(command)
 
 		if err != nil {
-			fmt.Printf("Error executing '%s': %v\n", command, err)
+			fmt.Printf("%s: Error executing '%s': %v\n", rb.hostname, command, err)
 			hasErrors = true
 			continue
 		}
@@ -235,24 +269,28 @@ func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) erro
 		// Append to temporary file
 		file, err := os.OpenFile(tempPath, os.O_APPEND|os.O_WRONLY, 0644)
 		if err != nil {
-			fmt.Printf("Failed to open file for writing: %v\n", err)
+			fmt.Printf("%s: Failed to open file for writing: %v\n", rb.hostname, err)
 			hasErrors = true
 			continue
 		}
 
 		fmt.Fprintf(file, "## COMMAND: %s\n", command)
-		file.WriteString(output)
+		filteredOutput := filterOutput(output, excludePatterns)
+		if _, err := file.WriteString(filteredOutput); err != nil {
+			fmt.Printf("%s: Failed to write output: %v\n", rb.hostname, err)
+			hasErrors = true
+		}
 		file.Close()
 
 		successCount++
 	}
 
-	fmt.Printf("Summary: %d/%d commands successful\n", successCount, len(commands))
+	fmt.Printf("%s: Summary: %d/%d commands successful\n", rb.hostname, successCount, len(commands))
 
 	if hasErrors || successCount == 0 {
 		// Remove .new suffix and log error
 		if err := os.Remove(tempPath); err != nil {
-			fmt.Printf("Failed to remove temporary file %s: %v\n", tempPath, err)
+			fmt.Printf("%s: Failed to remove temporary file %s: %v\n", rb.hostname, tempPath, err)
 		}
 		return fmt.Errorf("device backup incomplete due to command failures")
 	}
@@ -262,7 +300,7 @@ func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) erro
 		return fmt.Errorf("failed to move temporary file to final location: %v", err)
 	}
 
-	fmt.Printf("Output saved to %s\n", finalPath)
+	fmt.Printf("%s: Output saved to %s\n", rb.hostname, finalPath)
 	return nil
 }
 
@@ -270,7 +308,7 @@ func (rb *RouterBackup) BackupCommands(commands []string, outputDir string) erro
 func (rb *RouterBackup) Disconnect() {
 	if rb.client != nil {
 		rb.client.Close()
-		fmt.Printf("Disconnected from %s\n", rb.hostname)
+		fmt.Printf("%s: Disconnected\n", rb.hostname)
 	}
 }
 
@@ -289,7 +327,7 @@ func findDefaultSSHKey() string {
 
 	for _, keyPath := range defaultKeys {
 		if _, err := os.Stat(keyPath); err == nil {
-			fmt.Printf("Using SSH key: %s\n", keyPath)
+			// Key discovery logging moved to main.go for hostname context
 			return keyPath
 		}
 	}

src/ssh_test.go

@@ -57,17 +57,22 @@ func TestBackupCommandsDirectoryCreation(t *testing.T) {
 
 	// This should create the directory even without a connection
 	// and fail gracefully when trying to run commands
-	_ = rb.BackupCommands([]string{"show version"}, outputDir)
+	err := rb.BackupCommands([]string{"show version"}, []string{}, outputDir)
 
 	// Should not error on directory creation
 	if _, statErr := os.Stat(outputDir); os.IsNotExist(statErr) {
 		t.Error("Expected output directory to be created")
 	}
 
-	// Should create the output file even if commands fail
+	// Should return error when commands fail
+	if err == nil {
+		t.Error("Expected error when commands fail")
+	}
+
+	// Should NOT create the output file when commands fail (atomic behavior)
 	expectedFile := filepath.Join(outputDir, "testhost")
-	if _, statErr := os.Stat(expectedFile); os.IsNotExist(statErr) {
-		t.Error("Expected output file to be created")
+	if _, statErr := os.Stat(expectedFile); !os.IsNotExist(statErr) {
+		t.Error("Expected output file to NOT be created when commands fail")
 	}
 }
 
@@ -76,15 +81,15 @@ func TestBackupCommandsEmptyCommands(t *testing.T) {
 
 	rb := NewRouterBackup("testhost", "", "testuser", "testpass", "", 22)
 
-	err := rb.BackupCommands([]string{}, tempDir)
-	if err != nil {
-		t.Errorf("Expected no error for empty commands list, got %v", err)
+	err := rb.BackupCommands([]string{}, []string{}, tempDir)
+	if err == nil {
+		t.Error("Expected error for empty commands list (no successful commands)")
 	}
 
-	// Should still create the output file
+	// Should NOT create the output file when no commands succeed
 	expectedFile := filepath.Join(tempDir, "testhost")
-	if _, statErr := os.Stat(expectedFile); os.IsNotExist(statErr) {
-		t.Error("Expected output file to be created even for empty commands")
+	if _, statErr := os.Stat(expectedFile); !os.IsNotExist(statErr) {
+		t.Error("Expected output file to NOT be created when no commands succeed")
 	}
 }
 
@@ -160,20 +165,19 @@ func TestBackupCommandsFileOperations(t *testing.T) {
 	// Create some fake commands (they will fail but we can test file operations)
 	commands := []string{"show version", "show interfaces"}
 
-	err := rb.BackupCommands(commands, tempDir)
-	if err != nil {
-		t.Errorf("Unexpected error: %v", err)
+	err := rb.BackupCommands(commands, []string{}, tempDir)
+	if err == nil {
+		t.Error("Expected error when all commands fail")
 	}
 
-	// Check that output file was created
+	// Check that output file was NOT created (atomic behavior)
 	outputFile := filepath.Join(tempDir, "testhost")
 	_, err = os.ReadFile(outputFile)
-	if err != nil {
-		t.Fatalf("Failed to read output file: %v", err)
+	if err == nil {
+		t.Error("Expected output file to not exist when all commands fail")
 	}
 
-	// File should be created (it will be empty if all commands fail)
-	// This test just verifies the file creation works
+	// This test verifies that atomic file behavior works correctly
 }
 
 func TestRouterBackupConnectionState(t *testing.T) {
@@ -281,3 +285,38 @@ func TestIPv6AddressFormatting(t *testing.T) {
 		t.Error("Expected IPv4 address to use tcp4 network type")
 	}
 }
+
+func TestFilterOutput(t *testing.T) {
+	// Test with no exclude patterns
+	input := "line1\nline2\nline3"
+	result := filterOutput(input, []string{})
+	if result != input {
+		t.Errorf("Expected no filtering with empty patterns, got '%s'", result)
+	}
+
+	// Test with matching pattern
+	input = "# 2025-07-06 21:30:45 by RouterOS\nconfig line 1\nconfig line 2"
+	excludePatterns := []string{"^# ....-..-.. ..:..:.. by RouterOS"}
+	expected := "config line 1\nconfig line 2"
+	result = filterOutput(input, excludePatterns)
+	if result != expected {
+		t.Errorf("Expected '%s', got '%s'", expected, result)
+	}
+
+	// Test with multiple patterns
+	input = "line1\nDEBUG: debug info\nline2\nINFO: info message\nline3"
+	excludePatterns = []string{"^DEBUG:", "^INFO:"}
+	expected = "line1\nline2\nline3"
+	result = filterOutput(input, excludePatterns)
+	if result != expected {
+		t.Errorf("Expected '%s', got '%s'", expected, result)
+	}
+
+	// Test with no matches
+	input = "line1\nline2\nline3"
+	excludePatterns = []string{"nomatch"}
+	result = filterOutput(input, excludePatterns)
+	if result != input {
+		t.Errorf("Expected no filtering when patterns don't match, got '%s'", result)
+	}
+}