Feature: alias command

cmd/alias.go

@@ -0,0 +1,36 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/fatih/color"
+	"github.com/spf13/cobra"
+
+	"github.com/tfversion/tfversion/pkg/alias"
+)
+
+const (
+	aliasExample = "# Alias a Terraform version\n" +
+		"tfversion alias default 1.7.4"
+)
+
+var (
+	aliasCmd = &cobra.Command{
+		Use:     "alias",
+		Short:   "Alias a Terraform version",
+		Example: aliasExample,
+		Run: func(cmd *cobra.Command, args []string) {
+			if len(args) != 2 {
+				fmt.Println("error: provide an alias name and Terraform version")
+				fmt.Printf("See %s for help and examples\n", color.CyanString("`tfversion alias -h`"))
+				os.Exit(1)
+			}
+			alias.AliasVersion(args[0], args[1])
+		},
+	}
+)
+
+func init() {
+	rootCmd.AddCommand(aliasCmd)
+}

pkg/alias/alias.go

@@ -0,0 +1,47 @@
+package alias
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/fatih/color"
+	"github.com/tfversion/tfversion/pkg/download"
+	"github.com/tfversion/tfversion/pkg/helpers"
+)
+
+func AliasVersion(alias string, version string) {
+	if !download.IsAlreadyDownloaded(version) {
+		if helpers.IsPreReleaseVersion(version) {
+			fmt.Printf("Terraform version %s not found, run %s to install\n", color.YellowString(version), color.CyanString(fmt.Sprintf("`tfversion install %s`", version)))
+		} else {
+			fmt.Printf("Terraform version %s not found, run %s to install\n", color.CyanString(version), color.CyanString(fmt.Sprintf("`tfversion install %s`", version)))
+		}
+		os.Exit(0)
+	}
+
+	// delete existing alias symlink, we consider it non-destructive anyways since you can easily restore it
+	aliasPath := filepath.Join(download.GetDownloadLocation(), alias)
+	_, err := os.Lstat(aliasPath)
+	if err == nil {
+		err = os.RemoveAll(aliasPath)
+		if err != nil {
+			fmt.Printf("error removing symlink: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
+	// create the symlink
+	binaryVersionPath := download.GetInstallLocation(version)
+	err = os.Symlink(binaryVersionPath, aliasPath)
+	if err != nil {
+		fmt.Printf("error creating symlink: %v\n", err)
+		os.Exit(1)
+	}
+
+	if helpers.IsPreReleaseVersion(version) {
+		fmt.Printf("Aliased Terraform version %s as %s\n", color.YellowString(version), color.YellowString(alias))
+	} else {
+		fmt.Printf("Aliased Terraform version %s as %s\n", color.CyanString(version), color.CyanString(alias))
+	}
+}