Merge pull request GoogleCloudPlatform#2759 from mr0re1/better_version

Add terraform version to `ghpc --version`

cmd/root.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"hpc-toolkit/pkg/config"
 	"hpc-toolkit/pkg/logging"
+	"hpc-toolkit/pkg/shell"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -79,13 +80,21 @@ func Execute() error {
 		if len(GitBranch) == 0 {
 			GitBranch = "detached HEAD"
 		}
+
 		annotation["version"] = GitTagVersion
 		annotation["branch"] = GitBranch
 		annotation["commitInfo"] = GitCommitInfo
-		rootCmd.SetVersionTemplate(`ghpc version {{index .Annotations "version"}}
+		tmpl := `ghpc version {{index .Annotations "version"}}
 Built from '{{index .Annotations "branch"}}' branch.
 Commit info: {{index .Annotations "commitInfo"}}
-`)
+`
+		tfVersion, _ := shell.TfVersion()
+		if tfVersion != "" {
+			annotation["tfVersion"] = tfVersion
+			tmpl += `Terraform version: {{index .Annotations "tfVersion"}}
+`
+		}
+		rootCmd.SetVersionTemplate(tmpl)
 	}
 
 	return rootCmd.Execute()

pkg/shell/terraform.go

@@ -54,14 +54,21 @@ type outputValue struct {
 	Value     cty.Value
 }
 
-// ConfigureTerraform returns a Terraform object used to execute commands
-func ConfigureTerraform(workingDir string) (*tfexec.Terraform, error) {
+func tfExecPath() (string, error) {
 	path, err := exec.LookPath("terraform")
 	if err != nil {
-		return nil, config.HintError{
+		return "", config.HintError{
 			Hint: "must have a copy of terraform installed in PATH (obtain at https://terraform.io)",
-			Err:  err,
-		}
+			Err:  err}
+	}
+	return path, nil
+}
+
+// ConfigureTerraform returns a Terraform object used to execute commands
+func ConfigureTerraform(workingDir string) (*tfexec.Terraform, error) {
+	path, err := tfExecPath()
+	if err != nil {
+		return nil, err
 	}
 	return tfexec.NewTerraform(workingDir, path)
 }
@@ -424,3 +431,24 @@ func ImportInputs(groupDir string, artifactsDir string, bp config.Blueprint) err
 func Destroy(tf *tfexec.Terraform, b ApplyBehavior) error {
 	return applyOrDestroy(tf, b, true)
 }
+
+func TfVersion() (string, error) {
+	path, err := tfExecPath()
+	if err != nil {
+		return "", err
+	}
+
+	out, err := exec.Command(path, "version", "--json").Output()
+	if err != nil {
+		return "", err
+	}
+
+	var version struct {
+		TerraformVersion string `json:"terraform_version"`
+	}
+	if err := json.Unmarshal(out, &version); err != nil {
+		return "", err
+	}
+
+	return version.TerraformVersion, nil
+}