fix(provisioner/terraform/tfparse): skip evaluating variables/parameters not referenced by workspace_tags

johnstcn · johnstcn · commit e48b1066251d · 2025-01-03T11:34:35.000Z
diff --git a/coderd/templateversions_test.go b/coderd/templateversions_test.go
@@ -358,6 +358,7 @@ func TestPostTemplateVersionsByOrganization(t *testing.T) {
 				name: "main.tf with workspace tags and request tags",
 				files: map[string]string{
 					`main.tf`: `
+						// This file is the same as the above, except for this comment.
 						variable "a" {
 							type = string
 							default = "1"
diff --git a/provisioner/terraform/tfparse/tfparse.go b/provisioner/terraform/tfparse/tfparse.go
@@ -172,11 +172,11 @@ func (p *Parser) WorkspaceTagDefaults(ctx context.Context) (map[string]string, e
 
 	// To evaluate the expressions, we need to load the default values for
 	// variables and parameters.
-	varsDefaults, err := p.VariableDefaults(ctx)
+	varsDefaults, err := p.VariableDefaults(ctx, tags)
 	if err != nil {
 		return nil, xerrors.Errorf("load variable defaults: %w", err)
 	}
-	paramsDefaults, err := p.CoderParameterDefaults(ctx, varsDefaults)
+	paramsDefaults, err := p.CoderParameterDefaults(ctx, varsDefaults, tags)
 	if err != nil {
 		return nil, xerrors.Errorf("load parameter defaults: %w", err)
 	}
@@ -251,28 +251,39 @@ func WriteArchive(bs []byte, mimetype string, path string) error {
 	return nil
 }
 
-// VariableDefaults returns the default values for all variables passed to it.
-func (p *Parser) VariableDefaults(ctx context.Context) (map[string]string, error) {
+// VariableDefaults returns the default values for all variables referenced in the values of tags.
+func (p *Parser) VariableDefaults(ctx context.Context, tags map[string]string) (map[string]string, error) {
+	var skipped []string
 	// iterate through vars to get the default values for all
-	// variables.
+	// required variables.
 	m := make(map[string]string)
 	for _, v := range p.module.Variables {
 		if v == nil {
 			continue
 		}
+		var found bool
+		for _, tv := range tags {
+			if strings.Contains(tv, v.Name) {
+				found = true
+			}
+		}
+		if !found {
+			skipped = append(skipped, v.Name)
+			continue
+		}
 		sv, err := interfaceToString(v.Default)
 		if err != nil {
 			return nil, xerrors.Errorf("can't convert variable default value to string: %v", err)
 		}
 		m[v.Name] = strings.Trim(sv, `"`)
 	}
-	p.logger.Debug(ctx, "found default values for variables", slog.F("defaults", m))
+	p.logger.Debug(ctx, "found default values for variables", slog.F("defaults", m), slog.F("skipped", skipped))
 	return m, nil
 }
 
 // CoderParameterDefaults returns the default values of all coder_parameter data sources
 // in the parsed module.
-func (p *Parser) CoderParameterDefaults(ctx context.Context, varsDefaults map[string]string) (map[string]string, error) {
+func (p *Parser) CoderParameterDefaults(ctx context.Context, varsDefaults map[string]string, tags map[string]string) (map[string]string, error) {
 	defaultsM := make(map[string]string)
 	var (
 		skipped []string
@@ -294,6 +305,17 @@ func (p *Parser) CoderParameterDefaults(ctx context.Context, varsDefaults map[st
 			continue
 		}
 
+		var found bool
+		for _, tv := range tags {
+			if strings.Contains(tv, dataResource.Name) {
+				found = true
+			}
+		}
+		if !found {
+			skipped = append(skipped, dataResource.Name)
+			continue
+		}
+
 		// We know in which HCL file is the data resource defined.
 		// NOTE: hclparse.Parser will cache multiple successive calls to parse the same file.
 		file, diags = p.underlying.ParseHCLFile(dataResource.Pos.Filename)
