cmd/openshift-install: Add Terraform version to 'version' output

And print the error information if we can't extract it.

The .Stderr stuffing is because Terraform just prints usage
information to stdout (not stderr!) if you call it with an
unrecognized command:

  $ terraform does-not-exit >stdout 2>stderr
  $ head -n1 stdout
  Usage: terraform [-version] [-help] <command> [args]
  $ ls -l stderr
  -rw-r--r--. 1 trking trking 0 Oct  2 17:14 stderr

and in this case we want to see that usage information.  Ideally
Terraform would have printed "unrecognized command 'does-no-exist'" or
some such to stderr, but that's a bit bigger than we can work around
here.

.github/ISSUE_TEMPLATE.md

@@ -7,26 +7,13 @@ If we can't reproduce a bug we might close your issue.
 If we're wrong, PLEASE feel free to reopen it and explain why.
 -->
 
-# Versions
-
-## Installer version:
+# Version
 
 ```console
 $ openshift-install version
 <your output here>
 ```
 
-## Terraform version
-
-<!---
-If you are not running the latest version of Terraform, please try upgrading because your issue may have already been fixed.
--->
-
-```console
-$ terraform version
-<your output here>
-```
-
 # Platform (aws|libvirt|openshift):
 
 Enter text here.

cmd/openshift-install/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"os/exec"
 
 	"github.com/sirupsen/logrus"
 	"gopkg.in/alecthomas/kingpin.v2"
@@ -11,6 +12,7 @@ import (
 	"github.com/openshift/installer/pkg/asset/stock"
 	"github.com/openshift/installer/pkg/destroy"
 	_ "github.com/openshift/installer/pkg/destroy/libvirt"
+	"github.com/openshift/installer/pkg/terraform"
 )
 
 var (
@@ -44,6 +46,15 @@ func main() {
 
 	if command == versionCommand.FullCommand() {
 		fmt.Printf("%s %s\n", os.Args[0], version)
+		terraformVersion, err := terraform.Version()
+		if err != nil {
+			exitError, ok := err.(*exec.ExitError)
+			if ok && len(exitError.Stderr) > 0 {
+				logrus.Error(string(exitError.Stderr))
+			}
+			logrus.Fatalf("Failed to calculate Terraform version: %v", err)
+		}
+		fmt.Println(terraformVersion)
 		return
 	}
 

pkg/terraform/executor.go

@@ -7,6 +7,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 )
@@ -73,6 +74,24 @@ func (ex *executor) execute(clusterDir string, args ...string) error {
 	return cmd.Run()
 }
 
+// Version gets the output of 'terrraform version'.
+func Version() (version string, err error) {
+	// Find the Terraform binary.
+	binPath, err := tfBinaryPath()
+	if err != nil {
+		return "", err
+	}
+
+	output, err := exec.Command(binPath, "version").Output()
+	if err != nil {
+		exitError := err.(*exec.ExitError)
+		if len(exitError.Stderr) == 0 {
+			exitError.Stderr = output
+		}
+	}
+	return strings.TrimRight(string(output), "\n"), err
+}
+
 // tfBinaryPath searches for a Terraform binary on disk:
 // - in the executing binary's folder,
 // - in the current working directory,