add fish support

cmd/completion.go

@@ -21,7 +21,7 @@ func newCompletionCmd() *completionCmd {
 	cc := completionCmd{}
 
 	cc.cmd = &cobra.Command{
-		Use:   "completion [bash|zsh]",
+		Use:   "completion [bash|zsh|fish]",
 		Short: "Generate completion script",
 		Long: `To load completions:
 
@@ -43,7 +43,7 @@ Zsh:
 
 `,
 		DisableFlagsInUseLine: true,
-		ValidArgs:             []string{"bash", "zsh"},
+		ValidArgs:             []string{"bash", "zsh", "fish"},
 		Args:                  cobra.ExactValidArgs(1),
 		RunE:                  cc.completion,
 	}
@@ -88,6 +88,19 @@ func (c *completionCmd) completion(cmd *cobra.Command, args []string) error {
 
 		os.Stdout.WriteString(genBash)
 
+	case "fish":
+		const name = "konf-go"
+		var b bytes.Buffer
+		rootCmd.Use = name
+		err := rootCmd.GenFishCompletion(&b, true)
+		if err != nil {
+			return err
+		}
+		anchor := "complete -c " + name
+		genFish := strings.Replace(b.String(), anchor, anchor+" -w konf", 2) // this is a bit different as we have to replace two occurrences of the anchor
+
+		os.Stdout.WriteString(genFish)
+
 	default:
 		return fmt.Errorf("konf currently does not support autocompletions for %s", args[0])
 	}

cmd/shellwrapper.go

@@ -67,6 +67,26 @@ konf_cleanup() {
   konf-go cleanup
 }
 
+trap konf_cleanup EXIT
+`
+
+	var fish = `
+function konf -w konf-go
+    set -f res (konf-go $argv)
+    # only change $KUBECONFIG if instructed by konf-go
+    if string match -q 'KUBECONFIGCHANGE:*' $res
+        # this basically takes the line and cuts out the KUBECONFIGCHANGE Part
+        set -gx KUBECONFIG (string replace -r '^KUBECONFIGCHANGE:' '' $res)
+    else
+        # this makes --help work
+        printf "%s\n" $res
+    end
+end
+
+function konf_cleanup
+    konf-go cleanup
+end
+
 trap konf_cleanup EXIT
 `
 
@@ -75,6 +95,8 @@ trap konf_cleanup EXIT
 		wrapper = zsh
 	case "bash":
 		wrapper = bash
+	case "fish":
+		wrapper = fish
 	default:
 		return fmt.Errorf("konf currently does not support %s", args[0])
 	}