Add goversion, goos, and goarch to version command (hashicorp#407)

* add goversion, goos and goarch for build

* support for json flag

* fix based on hashicorp#407 (review)

.github/workflows/ci.yml

@@ -94,7 +94,7 @@ jobs:
       -
         name: Run tests
         run: make test
-      - 
+      -
         name: Upload code coverage report
         uses: codecov/codecov-action@v1
         with:

internal/cmd/version_command.go

@@ -4,13 +4,16 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"runtime"
 	"strings"
 
 	"github.com/mitchellh/cli"
 )
 
 type VersionOutput struct {
 	Version string `json:"version"`
+
+	*BuildInfo
 }
 
 type VersionCommand struct {
@@ -20,6 +23,13 @@ type VersionCommand struct {
 	jsonOutput bool
 }
 
+type BuildInfo struct {
+	GoVersion string `json:"go,omitempty"`
+	GoOS      string `json:"os,omitempty"`
+	GoArch    string `json:"arch,omitempty"`
+	Compiler  string `json:"compiler,omitempty"`
+}
+
 func (c *VersionCommand) flags() *flag.FlagSet {
 	fs := defaultFlagSet("version")
 
@@ -37,10 +47,17 @@ func (c *VersionCommand) Run(args []string) int {
 		return 1
 	}
 
+	output := VersionOutput{
+		Version: c.Version,
+		BuildInfo: &BuildInfo{
+			GoVersion: runtime.Version(),
+			GoOS:      runtime.GOOS,
+			GoArch:    runtime.GOARCH,
+			Compiler:  runtime.Compiler,
+		},
+	}
+
 	if c.jsonOutput {
-		output := VersionOutput{
-			Version: c.Version,
-		}
 		jsonOutput, err := json.MarshalIndent(output, "", "  ")
 		if err != nil {
 			c.Ui.Error(fmt.Sprintf("\nError marshalling JSON: %s", err))
@@ -50,7 +67,8 @@ func (c *VersionCommand) Run(args []string) int {
 		return 0
 	}
 
-	c.Ui.Output(string(c.Version))
+	ver := fmt.Sprintf("%s\nplatform: %s/%s\ngo: %s\ncompiler: %s", c.Version, output.GoOS, output.GoArch, output.GoVersion, output.Compiler)
+	c.Ui.Output(ver)
 	return 0
 }