Fix lint errors, ensure errors start with 'hostname:'

src/config.go

@@ -4,7 +4,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 
 	"dario.cat/mergo"
 	"gopkg.in/yaml.v3"
@@ -29,7 +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

@@ -217,7 +217,9 @@ func main() {
 	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

@@ -4,7 +4,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"path/filepath"
@@ -145,11 +144,11 @@ 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))
 			}
@@ -268,7 +267,10 @@ func (rb *RouterBackup) BackupCommands(commands []string, excludePatterns []stri
 
 		fmt.Fprintf(file, "## COMMAND: %s\n", command)
 		filteredOutput := filterOutput(output, excludePatterns)
-		file.WriteString(filteredOutput)
+		if _, err := file.WriteString(filteredOutput); err != nil {
+			fmt.Printf("%s: Failed to write output: %v\n", rb.hostname, err)
+			hasErrors = true
+		}
 		file.Close()
 
 		successCount++