Add autocompletion generation for more shells

.goreleaser.yml

@@ -72,6 +72,8 @@ brews:
       bin.install "exo"
       man1.install Dir["manpage/exo*.1"]
       bash_completion.install "contrib/completion/bash/exo"
+      fish_completion.install "contrib/completion/fish/exo"
+      zsh_completion.install "contrib/completion/zsh/exo"
 
 dockers:
   - goos: linux

Makefile

@@ -45,9 +45,11 @@ manpages: manpage
 
 .PHONY: completions
 completions:
-	mkdir -p contrib/completion/bash
-	$(GO) run -mod vendor completion/main.go
-	mv bash_completion contrib/completion/bash/exo
+	mkdir -p contrib/completion/{bash,fish,powershell,zsh}
+	$(GO) run -mod vendor completion/main.go bash ; mv bash_completion contrib/completion/bash/exo
+	$(GO) run -mod vendor completion/main.go fish ; mv fish_completion contrib/completion/fish/exo
+	$(GO) run -mod vendor completion/main.go powershell ; mv powershell_completion contrib/completion/powershell/exo
+	$(GO) run -mod vendor completion/main.go zsh ; mv zsh_completion contrib/completion/zsh/exo
 
 .PHONY: clean
 clean::

completion/main.go

@@ -2,12 +2,35 @@ package main
 
 import (
 	"log"
+	"os"
 
 	"github.com/exoscale/cli/cmd"
 )
 
 func main() {
-	if err := cmd.RootCmd.GenBashCompletionFile("bash_completion"); err != nil {
+	if len(os.Args) != 2 {
+		log.Fatalf("usage: %s (bash|fish|powershell|zsh)", os.Args[0])
+	}
+
+	var err error
+	switch os.Args[1] {
+	case "bash":
+		err = cmd.RootCmd.GenBashCompletionFile("bash_completion")
+
+	case "fish":
+		err = cmd.RootCmd.GenFishCompletionFile("fish_completion", true)
+
+	case "powershell":
+		err = cmd.RootCmd.GenPowerShellCompletionFile("powershell_completion")
+
+	case "zsh":
+		err = cmd.RootCmd.GenZshCompletionFile("zsh_completion")
+
+	default:
+		log.Fatalf("unsupported shell %q", os.Args[1])
+	}
+
+	if err != nil {
 		log.Fatal(err)
 	}
 }