Add VersionString

We conditionally format version with VersionPrerelease in a number of
places. Add a package-level function where we can unify the version
format. Replace most of version formatting in terraform, but leave th
few instances set from the top-level package to make sure we don't break
anything before release.

builtin/providers/atlas/provider.go

@@ -52,7 +52,7 @@ func providerConfigure(d *schema.ResourceData) (interface{}, error) {
 			return nil, err
 		}
 	}
-	client.DefaultHeader.Set(terraform.VersionHeader, terraform.Version)
+	client.DefaultHeader.Set(terraform.VersionHeader, terraform.VersionString())
 	client.Token = d.Get("token").(string)
 
 	return client, nil

builtin/providers/aws/config.go

@@ -397,7 +397,7 @@ func (c *Config) ValidateAccountId(accountId string) error {
 var addTerraformVersionToUserAgent = request.NamedHandler{
 	Name: "terraform.TerraformVersionUserAgentHandler",
 	Fn: request.MakeAddToUserAgentHandler(
-		"terraform", terraform.Version, terraform.VersionPrerelease),
+		"terraform", terraform.VersionString()),
 }
 
 type awsLogger struct{}

builtin/providers/azurerm/config.go

@@ -92,13 +92,7 @@ func withRequestLogging() autorest.SendDecorator {
 }
 
 func setUserAgent(client *autorest.Client) {
-	var version string
-	if terraform.VersionPrerelease != "" {
-		version = fmt.Sprintf("%s-%s", terraform.Version, terraform.VersionPrerelease)
-	} else {
-		version = terraform.Version
-	}
-
+	version := terraform.VersionString()
 	client.UserAgent = fmt.Sprintf("HashiCorp-Terraform-v%s", version)
 }
 

builtin/providers/google/config.go

@@ -85,11 +85,7 @@ func (c *Config) loadAndValidate() error {
 		}
 	}
 
-	versionString := terraform.Version
-	prerelease := terraform.VersionPrerelease
-	if len(prerelease) > 0 {
-		versionString = fmt.Sprintf("%s-%s", versionString, prerelease)
-	}
+	versionString := terraform.VersionString()
 	userAgent := fmt.Sprintf(
 		"(%s %s) Terraform/%s", runtime.GOOS, runtime.GOARCH, versionString)
 

terraform/version.go

@@ -1,6 +1,8 @@
 package terraform
 
 import (
+	"fmt"
+
 	"github.com/hashicorp/go-version"
 )
 
@@ -20,3 +22,10 @@ var SemVersion = version.Must(version.NewVersion(Version))
 // VersionHeader is the header name used to send the current terraform version
 // in http requests.
 const VersionHeader = "Terraform-Version"
+
+func VersionString() string {
+	if VersionPrerelease != "" {
+		return fmt.Sprintf("%s-%s", Version, VersionPrerelease)
+	}
+	return Version
+}