Add support for using goss to target Windows (#39)

* Add support for using goss to target Windows

README.md

@@ -2,7 +2,7 @@
 
 Wouldn't it be nice if you could run [goss](https://github.com/aelsabbahy/goss) tests against an image during a packer build?
 
-Well, I thought it would, so now you can!  This currently only works for building a `linux` image since goss only runs in linux.
+Well, I thought it would, so now you can!  
 
 This runs during the provisioning process since the machine being provisioned is only available at that time.
 
@@ -50,6 +50,7 @@ There is an example packer build with goss tests in the `example/` directory.
     "format": "",
     "goss_file": "",
     "vars_file": "",
+    "targetOs": "Linux",
     "vars_env": {
       "ARCH": "amd64",
       "PROVIDER": "{{user `cloud-provider`}}"
@@ -67,6 +68,10 @@ There is an example packer build with goss tests in the `example/` directory.
 ## Spec files
 Goss spec file and debug spec file (`goss render -d`) are downloaded to `/tmp` folder on local machine from the remote VM. These files are exact specs GOSS validated on the VM. The downloaded GOSS spec can be used to validate any other VM image for equivalency.  
 
+## Windows support
+
+This now has support for Windows. Set the optional parameter `targetOs` to `Windows`. Currently, the `vars_env` parameter must include `GOSS_USE_ALPHA=1` as specified in [goss's feature parity document](https://github.com/aelsabbahy/goss/blob/master/docs/platform-feature-parity.md#platform-feature-parity).  In the future when goss come of of alpha for Windows this parameter will not be required.
+
 ## Installation
 
 1. Download the most recent release for your platform from [here.](https://github.com/YaleUniversity/packer-provisioner-goss/releases).
@@ -91,6 +96,7 @@ Goss spec file and debug spec file (`goss render -d`) are downloaded to `/tmp` f
 
 ```bash
 docker run --rm -it -v "$PWD":/usr/src/packer-provisioner-goss -w /usr/src/packer-provisioner-goss -e 'VERSION=v1.0.0' golang:1.13 bash
+go test ./...
 for GOOS in darwin linux windows; do
   for GOARCH in 386 amd64; do
     export GOOS GOARCH

packer-provisioner-goss.go

@@ -19,8 +19,12 @@ import (
 	"github.com/hashicorp/packer/template/interpolate"
 )
 
-const gossSpecFile = "/tmp/goss-spec.yaml"
-const gossDebugSpecFile = "/tmp/debug-goss-spec.yaml"
+const (
+	gossSpecFile      = "/tmp/goss-spec.yaml"
+	gossDebugSpecFile = "/tmp/debug-goss-spec.yaml"
+	linux             = "Linux"
+	windows           = "Windows"
+)
 
 // GossConfig holds the config data coming in from the packer template
 type GossConfig struct {
@@ -33,6 +37,7 @@ type GossConfig struct {
 	Password     string
 	SkipInstall  bool
 	Inspect      bool
+	TargetOs     string
 
 	// An array of tests to run.
 	Tests []string
@@ -126,20 +131,31 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 		p.config.Arch = "amd64"
 	}
 
+	if p.config.TargetOs == "" {
+		p.config.TargetOs = linux
+	}
+
 	if p.config.URL == "" {
-		p.config.URL = fmt.Sprintf(
-			"https://github.com/aelsabbahy/goss/releases/download/v%s/goss-linux-%s",
-			p.config.Version, p.config.Arch)
+		p.config.URL = p.getDownloadUrl()
 	}
 
 	if p.config.DownloadPath == "" {
+		os := strings.ToLower(p.config.TargetOs)
 		if p.config.URL == "" {
-			p.config.DownloadPath = fmt.Sprintf("/tmp/goss-%s-linux-%s", p.config.Version, p.config.Arch)
+			p.config.DownloadPath = fmt.Sprintf("/tmp/goss-%s-%s-%s", p.config.Version, os, p.config.Arch)
 		} else {
 			list := strings.Split(p.config.URL, "/")
-			arch := strings.Split(list[len(list)-1], "-")[2]
+
+			file := strings.Split(list[len(list)-1], "-")
+			arch := file[2]
+			if p.isGossAlpha() {
+				// The format of the alpha files includes an additional entry
+				// ex: goss-alpha-windows-amd64.exe
+				arch = file[3]
+			}
+
 			version := strings.TrimPrefix(list[len(list)-2], "v")
-			p.config.DownloadPath = fmt.Sprintf("/tmp/goss-%s-linux-%s", version, arch)
+			p.config.DownloadPath = fmt.Sprintf("/tmp/goss-%s-%s-%s", version, os, arch)
 		}
 	}
 
@@ -202,6 +218,11 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 		}
 	}
 
+	if p.config.TargetOs != linux && p.config.TargetOs != windows {
+		errs = packer.MultiErrorAppend(errs,
+			fmt.Errorf("Os must be %s or %s", linux, windows))
+	}
+
 	if errs != nil && len(errs.Errors) > 0 {
 		return errs
 	}
@@ -212,6 +233,12 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 // Provision runs the Goss Provisioner
 func (p *Provisioner) Provision(ctx context.Context, ui packer.Ui, comm packer.Communicator, generatedData map[string]interface{}) error {
 	ui.Say("Provisioning with Goss")
+	ui.Say(fmt.Sprintf("Configured to run on %s", string(p.config.TargetOs)))
+
+	// For Windows need to create the target directory before download
+	if err := p.createDir(ui, comm, p.config.RemotePath); err != nil {
+		return fmt.Errorf("Error creating remote directory: %s", err)
+	}
 
 	if !p.config.SkipInstall {
 		if err := p.installGoss(ui, comm); err != nil {
@@ -222,10 +249,6 @@ func (p *Provisioner) Provision(ctx context.Context, ui packer.Ui, comm packer.C
 	}
 
 	ui.Say("Uploading goss tests...")
-	if err := p.createDir(ui, comm, p.config.RemotePath); err != nil {
-		return fmt.Errorf("Error creating remote directory: %s", err)
-	}
-
 	if p.config.VarsFile != "" {
 		vf, err := os.Stat(p.config.VarsFile)
 		if err != nil {
@@ -416,18 +439,50 @@ func (p *Provisioner) inline_vars() string {
 	if len(p.config.VarsInline) != 0 {
 		inlineVarsJson, err := json.Marshal(p.config.VarsInline)
 		if err == nil {
-			return fmt.Sprintf("--vars-inline '%s'", string(inlineVarsJson))
+			switch p.config.TargetOs {
+			case windows:
+				// don't include single quotes which confused cmd parsing
+				return fmt.Sprintf("--vars-inline %s", string(inlineVarsJson))
+			default:
+				return fmt.Sprintf("--vars-inline '%s'", string(inlineVarsJson))
+			}
 		} else {
 			fmt.Errorf("Error converting inline vars to json string %v", err)
 		}
 	}
 	return ""
 }
 
+func (p *Provisioner) getDownloadUrl() string {
+	os := strings.ToLower(string(p.config.TargetOs))
+	filename := fmt.Sprintf("goss-%s-%s", os, p.config.Arch)
+
+	if p.isGossAlpha() {
+		filename = fmt.Sprintf("goss-alpha-%s-%s", os, p.config.Arch)
+	}
+
+	if p.config.TargetOs == windows {
+		filename = fmt.Sprintf("%s.exe", filename)
+	}
+
+	return fmt.Sprintf("https://github.com/aelsabbahy/goss/releases/download/v%s/%s", p.config.Version, filename)
+}
+
+func (p *Provisioner) isGossAlpha() bool {
+	return p.config.VarsEnv["GOSS_USE_ALPHA"] == "1"
+}
+
 func (p *Provisioner) envVars() string {
 	var sb strings.Builder
 	for env_var, value := range p.config.VarsEnv {
-		sb.WriteString(fmt.Sprintf("%s=\"%s\" ", env_var, value))
+		switch p.config.TargetOs {
+		case windows:
+			// Windows requires a call to "set" as separate command seperated by && for each env variable
+			sb.WriteString(fmt.Sprintf("set \"%s=%s\" && ", env_var, value))
+		default:
+			sb.WriteString(fmt.Sprintf("%s=\"%s\" ", env_var, value))
+		}
+
 	}
 	return sb.String()
 }
@@ -481,7 +536,7 @@ func (p *Provisioner) createDir(ui packer.Ui, comm packer.Communicator, dir stri
 	ctx := context.TODO()
 
 	cmd := &packer.RemoteCmd{
-		Command: fmt.Sprintf("mkdir -p '%s'", dir),
+		Command: p.mkDir(dir),
 	}
 	if err := cmd.RunWithUi(ctx, comm, ui); err != nil {
 		return err
@@ -492,6 +547,15 @@ func (p *Provisioner) createDir(ui packer.Ui, comm packer.Communicator, dir stri
 	return nil
 }
 
+func (p *Provisioner) mkDir(dir string) string {
+	switch p.config.TargetOs {
+	case windows:
+		return fmt.Sprintf("powershell /c mkdir -p '%s'", dir)
+	default:
+		return fmt.Sprintf("mkdir -p '%s'", dir)
+	}
+}
+
 // uploadFile uploads a file
 func (p *Provisioner) uploadFile(ui packer.Ui, comm packer.Communicator, dst, src string) error {
 	f, err := os.Open(src)