provider/template: convert resources to data sources

The template resources don't actually need to retain any state, so they
are good candidates to be data sources.

This includes a few tweaks to the acceptance tests -- now configured to
run as unit tests -- since it seems that they have been slightly broken
for a while now. In particular, the "update" cases are no longer tested
because updating is not a meaningful operation for a data source.

builtin/providers/template/resource_cloudinit_config.go → builtin/providers/template/datasource_cloudinit_config.go

@@ -15,13 +15,9 @@ import (
 	"github.com/sthulb/mime/multipart"
 )
 
-func resourceCloudinitConfig() *schema.Resource {
+func dataSourceCloudinitConfig() *schema.Resource {
 	return &schema.Resource{
-		Create: resourceCloudinitConfigCreate,
-		Delete: resourceCloudinitConfigDelete,
-		Update: resourceCloudinitConfigCreate,
-		Exists: resourceCloudinitConfigExists,
-		Read:   resourceCloudinitConfigRead,
+		Read: dataSourceCloudinitConfigRead,
 
 		Schema: map[string]*schema.Schema{
 			"part": &schema.Schema{
@@ -52,13 +48,11 @@ func resourceCloudinitConfig() *schema.Resource {
 				Type:     schema.TypeBool,
 				Optional: true,
 				Default:  true,
-				ForceNew: true,
 			},
 			"base64_encode": &schema.Schema{
 				Type:     schema.TypeBool,
 				Optional: true,
 				Default:  true,
-				ForceNew: true,
 			},
 			"rendered": &schema.Schema{
 				Type:        schema.TypeString,
@@ -69,7 +63,7 @@ func resourceCloudinitConfig() *schema.Resource {
 	}
 }
 
-func resourceCloudinitConfigCreate(d *schema.ResourceData, meta interface{}) error {
+func dataSourceCloudinitConfigRead(d *schema.ResourceData, meta interface{}) error {
 	rendered, err := renderCloudinitConfig(d)
 	if err != nil {
 		return err
@@ -80,24 +74,6 @@ func resourceCloudinitConfigCreate(d *schema.ResourceData, meta interface{}) err
 	return nil
 }
 
-func resourceCloudinitConfigDelete(d *schema.ResourceData, meta interface{}) error {
-	d.SetId("")
-	return nil
-}
-
-func resourceCloudinitConfigExists(d *schema.ResourceData, meta interface{}) (bool, error) {
-	rendered, err := renderCloudinitConfig(d)
-	if err != nil {
-		return false, err
-	}
-
-	return strconv.Itoa(hashcode.String(rendered)) == d.Id(), nil
-}
-
-func resourceCloudinitConfigRead(d *schema.ResourceData, meta interface{}) error {
-	return nil
-}
-
 func renderCloudinitConfig(d *schema.ResourceData) (string, error) {
 	gzipOutput := d.Get("gzip").(bool)
 	base64Output := d.Get("base64_encode").(bool)

builtin/providers/template/datasource_cloudinit_config_test.go

@@ -0,0 +1,80 @@
+package template
+
+import (
+	"testing"
+
+	r "github.com/hashicorp/terraform/helper/resource"
+)
+
+func TestRender(t *testing.T) {
+	testCases := []struct {
+		ResourceBlock string
+		Expected      string
+	}{
+		{
+			`data "template_cloudinit_config" "foo" {
+				gzip = false
+				base64_encode = false
+
+				part {
+					content_type = "text/x-shellscript"
+					content = "baz"
+				}
+			}`,
+			"Content-Type: multipart/mixed; boundary=\"MIMEBOUNDARY\"\nMIME-Version: 1.0\r\n--MIMEBOUNDARY\r\nContent-Transfer-Encoding: 7bit\r\nContent-Type: text/x-shellscript\r\nMime-Version: 1.0\r\n\r\nbaz\r\n--MIMEBOUNDARY--\r\n",
+		},
+		{
+			`data "template_cloudinit_config" "foo" {
+				gzip = false
+				base64_encode = false
+
+				part {
+					content_type = "text/x-shellscript"
+					content = "baz"
+					filename = "foobar.sh"
+				}
+			}`,
+			"Content-Type: multipart/mixed; boundary=\"MIMEBOUNDARY\"\nMIME-Version: 1.0\r\n--MIMEBOUNDARY\r\nContent-Disposition: attachment; filename=\"foobar.sh\"\r\nContent-Transfer-Encoding: 7bit\r\nContent-Type: text/x-shellscript\r\nMime-Version: 1.0\r\n\r\nbaz\r\n--MIMEBOUNDARY--\r\n",
+		},
+		{
+			`data "template_cloudinit_config" "foo" {
+				gzip = false
+				base64_encode = false
+
+				part {
+					content_type = "text/x-shellscript"
+					content = "baz"
+				}
+				part {
+					content_type = "text/x-shellscript"
+					content = "ffbaz"
+				}
+			}`,
+			"Content-Type: multipart/mixed; boundary=\"MIMEBOUNDARY\"\nMIME-Version: 1.0\r\n--MIMEBOUNDARY\r\nContent-Transfer-Encoding: 7bit\r\nContent-Type: text/x-shellscript\r\nMime-Version: 1.0\r\n\r\nbaz\r\n--MIMEBOUNDARY\r\nContent-Transfer-Encoding: 7bit\r\nContent-Type: text/x-shellscript\r\nMime-Version: 1.0\r\n\r\nffbaz\r\n--MIMEBOUNDARY--\r\n",
+		},
+	}
+
+	for _, tt := range testCases {
+		r.UnitTest(t, r.TestCase{
+			Providers: testProviders,
+			Steps: []r.TestStep{
+				r.TestStep{
+					Config: tt.ResourceBlock,
+					Check: r.ComposeTestCheckFunc(
+						r.TestCheckResourceAttr("data.template_cloudinit_config.foo", "rendered", tt.Expected),
+					),
+				},
+			},
+		})
+	}
+}
+
+var testCloudInitConfig_basic = `
+data "template_cloudinit_config" "config" {
+  part {
+    content_type = "text/x-shellscript"
+    content      = "baz"
+  }
+}`
+
+var testCloudInitConfig_basic_expected = `Content-Type: multipart/mixed; boundary=\"MIMEBOUNDARY\"\nMIME-Version: 1.0\r\n--MIMEBOUNDARY\r\nContent-Transfer-Encoding: 7bit\r\nContent-Type: text/x-shellscript\r\nMime-Version: 1.0\r\n\r\nbaz\r\n--MIMEBOUNDARY--\r\n`

builtin/providers/template/resource_template_file.go → builtin/providers/template/datasource_template_file.go

@@ -4,7 +4,6 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
-	"log"
 	"os"
 	"path/filepath"
 
@@ -15,27 +14,22 @@ import (
 	"github.com/hashicorp/terraform/helper/schema"
 )
 
-func resourceFile() *schema.Resource {
+func dataSourceFile() *schema.Resource {
 	return &schema.Resource{
-		Create: resourceFileCreate,
-		Delete: resourceFileDelete,
-		Exists: resourceFileExists,
-		Read:   resourceFileRead,
+		Read: dataSourceFileRead,
 
 		Schema: map[string]*schema.Schema{
 			"template": &schema.Schema{
 				Type:          schema.TypeString,
 				Optional:      true,
 				Description:   "Contents of the template",
-				ForceNew:      true,
 				ConflictsWith: []string{"filename"},
 				ValidateFunc:  validateTemplateAttribute,
 			},
 			"filename": &schema.Schema{
 				Type:        schema.TypeString,
 				Optional:    true,
 				Description: "file to read template from",
-				ForceNew:    true,
 				// Make a "best effort" attempt to relativize the file path.
 				StateFunc: func(v interface{}) string {
 					if v == nil || v.(string) == "" {
@@ -59,7 +53,6 @@ func resourceFile() *schema.Resource {
 				Optional:    true,
 				Default:     make(map[string]interface{}),
 				Description: "variables to substitute",
-				ForceNew:    true,
 			},
 			"rendered": &schema.Schema{
 				Type:        schema.TypeString,
@@ -70,7 +63,7 @@ func resourceFile() *schema.Resource {
 	}
 }
 
-func resourceFileCreate(d *schema.ResourceData, meta interface{}) error {
+func dataSourceFileRead(d *schema.ResourceData, meta interface{}) error {
 	rendered, err := renderFile(d)
 	if err != nil {
 		return err
@@ -80,32 +73,6 @@ func resourceFileCreate(d *schema.ResourceData, meta interface{}) error {
 	return nil
 }
 
-func resourceFileDelete(d *schema.ResourceData, meta interface{}) error {
-	d.SetId("")
-	return nil
-}
-
-func resourceFileExists(d *schema.ResourceData, meta interface{}) (bool, error) {
-	rendered, err := renderFile(d)
-	if err != nil {
-		if _, ok := err.(templateRenderError); ok {
-			log.Printf("[DEBUG] Got error while rendering in Exists: %s", err)
-			log.Printf("[DEBUG] Returning false so the template re-renders using latest variables from config.")
-			return false, nil
-		} else {
-			return false, err
-		}
-	}
-	return hash(rendered) == d.Id(), nil
-}
-
-func resourceFileRead(d *schema.ResourceData, meta interface{}) error {
-	// Logic is handled in Exists, which only returns true if the rendered
-	// contents haven't changed. That means if we get here there's nothing to
-	// do.
-	return nil
-}
-
 type templateRenderError error
 
 func renderFile(d *schema.ResourceData) (string, error) {

builtin/providers/template/resource_template_file_test.go → builtin/providers/template/datasource_template_file_test.go

@@ -23,13 +23,13 @@ func TestTemplateRendering(t *testing.T) {
 		want     string
 	}{
 		{`{}`, `ABC`, `ABC`},
-		{`{a="foo"}`, `${a}`, `foo`},
-		{`{a="hello"}`, `${replace(a, "ello", "i")}`, `hi`},
+		{`{a="foo"}`, `$${a}`, `foo`},
+		{`{a="hello"}`, `$${replace(a, "ello", "i")}`, `hi`},
 		{`{}`, `${1+2+3}`, `6`},
 	}
 
 	for _, tt := range cases {
-		r.Test(t, r.TestCase{
+		r.UnitTest(t, r.TestCase{
 			Providers: testProviders,
 			Steps: []r.TestStep{
 				r.TestStep{
@@ -47,39 +47,6 @@ func TestTemplateRendering(t *testing.T) {
 	}
 }
 
-// https://github.com/hashicorp/terraform/issues/2344
-func TestTemplateVariableChange(t *testing.T) {
-	steps := []struct {
-		vars     string
-		template string
-		want     string
-	}{
-		{`{a="foo"}`, `${a}`, `foo`},
-		{`{b="bar"}`, `${b}`, `bar`},
-	}
-
-	var testSteps []r.TestStep
-	for i, step := range steps {
-		testSteps = append(testSteps, r.TestStep{
-			Config: testTemplateConfig(step.template, step.vars),
-			Check: func(i int, want string) r.TestCheckFunc {
-				return func(s *terraform.State) error {
-					got := s.RootModule().Outputs["rendered"]
-					if want != got.Value {
-						return fmt.Errorf("[%d] got:\n%q\nwant:\n%q\n", i, got, want)
-					}
-					return nil
-				}
-			}(i, step.want),
-		})
-	}
-
-	r.Test(t, r.TestCase{
-		Providers: testProviders,
-		Steps:     testSteps,
-	})
-}
-
 func TestValidateTemplateAttribute(t *testing.T) {
 	file, err := ioutil.TempFile("", "testtemplate")
 	if err != nil {
@@ -129,11 +96,11 @@ func TestTemplateSharedMemoryRace(t *testing.T) {
 
 func testTemplateConfig(template, vars string) string {
 	return fmt.Sprintf(`
-		resource "template_file" "t0" {
+		data "template_file" "t0" {
 			template = "%s"
 			vars = %s
 		}
 		output "rendered" {
-				value = "${template_file.t0.rendered}"
+				value = "${data.template_file.t0.rendered}"
 		}`, template, vars)
 }

builtin/providers/template/provider.go

@@ -7,9 +7,19 @@ import (
 
 func Provider() terraform.ResourceProvider {
 	return &schema.Provider{
+		DataSourcesMap: map[string]*schema.Resource{
+			"template_file":             dataSourceFile(),
+			"template_cloudinit_config": dataSourceCloudinitConfig(),
+		},
 		ResourcesMap: map[string]*schema.Resource{
-			"template_file":             resourceFile(),
-			"template_cloudinit_config": resourceCloudinitConfig(),
+			"template_file": schema.DataSourceResourceShim(
+				"template_file",
+				dataSourceFile(),
+			),
+			"template_cloudinit_config": schema.DataSourceResourceShim(
+				"template_cloudinit_config",
+				dataSourceCloudinitConfig(),
+			),
 		},
 	}
 }