providers/template: disallow file paths in `template`

Fixes #8660

This disallows file paths in `template`. This already had a deprecation
warning so we're just removing that.

builtin/providers/template/datasource_template_file.go

@@ -25,7 +25,6 @@ func dataSourceFile() *schema.Resource {
 				Optional:      true,
 				Description:   "Contents of the template",
 				ConflictsWith: []string{"filename"},
-				ValidateFunc:  validateTemplateAttribute,
 			},
 			"filename": &schema.Schema{
 				Type:        schema.TypeString,
@@ -82,13 +81,14 @@ func renderFile(d *schema.ResourceData) (string, error) {
 	filename := d.Get("filename").(string)
 	vars := d.Get("vars").(map[string]interface{})
 
+	contents := template
 	if template == "" && filename != "" {
-		template = filename
-	}
+		data, _, err := pathorcontents.Read(filename)
+		if err != nil {
+			return "", err
+		}
 
-	contents, _, err := pathorcontents.Read(template)
-	if err != nil {
-		return "", err
+		contents = data
 	}
 
 	rendered, err := execute(contents, vars)
@@ -145,20 +145,6 @@ func hash(s string) string {
 	return hex.EncodeToString(sha[:])
 }
 
-func validateTemplateAttribute(v interface{}, key string) (ws []string, es []error) {
-	_, wasPath, err := pathorcontents.Read(v.(string))
-	if err != nil {
-		es = append(es, err)
-		return
-	}
-
-	if wasPath {
-		ws = append(ws, fmt.Sprintf("%s: looks like you specified a path instead of file contents. Use `file()` to load this path. Specifying a path directly is deprecated and will be removed in a future version.", key))
-	}
-
-	return
-}
-
 func validateVarsAttribute(v interface{}, key string) (ws []string, es []error) {
 	// vars can only be primitives right now
 	var badVars []string

builtin/providers/template/datasource_template_file_test.go

@@ -2,8 +2,6 @@ package template
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
 	"strings"
 	"sync"
 	"testing"
@@ -26,6 +24,7 @@ func TestTemplateRendering(t *testing.T) {
 		{`{a="foo"}`, `$${a}`, `foo`},
 		{`{a="hello"}`, `$${replace(a, "ello", "i")}`, `hi`},
 		{`{}`, `${1+2+3}`, `6`},
+		{`{}`, `/`, `/`},
 	}
 
 	for _, tt := range cases {
@@ -47,30 +46,6 @@ func TestTemplateRendering(t *testing.T) {
 	}
 }
 
-func TestValidateTemplateAttribute(t *testing.T) {
-	file, err := ioutil.TempFile("", "testtemplate")
-	if err != nil {
-		t.Fatal(err)
-	}
-	file.WriteString("Hello world.")
-	file.Close()
-	defer os.Remove(file.Name())
-
-	ws, es := validateTemplateAttribute(file.Name(), "test")
-
-	if len(es) != 0 {
-		t.Fatalf("Unexpected errors: %#v", es)
-	}
-
-	if len(ws) != 1 {
-		t.Fatalf("Expected 1 warning, got %d", len(ws))
-	}
-
-	if !strings.Contains(ws[0], "Specifying a path directly is deprecated") {
-		t.Fatalf("Expected warning about path, got: %s", ws[0])
-	}
-}
-
 func TestValidateVarsAttribute(t *testing.T) {
 	cases := map[string]struct {
 		Vars      map[string]interface{}