Merge pull request #37 from terraform-linters/meta_args_for_plugin

tflint: Support meta-arguments for terraform.Resource

Author: wata727

go.sum

@@ -66,6 +66,7 @@ github.com/oklog/run v1.0.0/go.mod h1:dlhp/R75TPv97u0XWUtDeV/lRKWPKSdTuV0TZvrmrQ
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

helper/runner.go

@@ -2,6 +2,8 @@ package helper
 
 import (
 	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/gohcl"
+	"github.com/terraform-linters/tflint-plugin-sdk/terraform"
 	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
 	"github.com/zclconf/go-cty/cty/gocty"
 )
@@ -59,7 +61,7 @@ func (r *Runner) WalkResourceAttributes(resourceType, attributeName string, walk
 }
 
 // WalkResources searches for resources with a specific type and passes to the walker function
-func (r *Runner) WalkResources(resourceType string, walker func(*tflint.Resource) error) error {
+func (r *Runner) WalkResources(resourceType string, walker func(*terraform.Resource) error) error {
 	for _, file := range r.Files {
 		resources, _, diags := file.Body.PartialContent(&hcl.BodySchema{
 			Blocks: []hcl.BlockHeaderSchema{
@@ -73,16 +75,17 @@ func (r *Runner) WalkResources(resourceType string, walker func(*tflint.Resource
 			return diags
 		}
 
-		for _, resource := range resources.Blocks {
-			if resource.Labels[0] != resourceType {
+		for _, block := range resources.Blocks {
+			resource, diags := simpleDecodeResouceBlock(block)
+			if diags.HasErrors() {
+				return diags
+			}
+
+			if resource.Type != resourceType {
 				continue
 			}
-			err := walker(&tflint.Resource{
-				Name:      resource.Labels[1],
-				Type:      resource.Labels[0],
-				DeclRange: resource.DefRange,
-				TypeRange: resource.LabelRanges[0],
-			})
+
+			err := walker(resource)
 			if err != nil {
 				return err
 			}
@@ -119,3 +122,174 @@ func (r *Runner) EnsureNoError(err error, proc func() error) error {
 	}
 	return err
 }
+
+// simpleDecodeResourceBlock decodes the data equivalent to configs.Resource from hcl.Block
+// without depending on Terraform. Some operations have been omitted for ease of implementation.
+// As such, it is expected to parse the minimal code needed for testing.
+// https://github.com/hashicorp/terraform/blob/v0.12.26/configs/resource.go#L78-L288
+func simpleDecodeResouceBlock(resource *hcl.Block) (*terraform.Resource, hcl.Diagnostics) {
+	content, resourceRemain, diags := resource.Body.PartialContent(&hcl.BodySchema{
+		Attributes: []hcl.AttributeSchema{
+			{
+				Name: "count",
+			},
+			{
+				Name: "for_each",
+			},
+			{
+				Name: "provider",
+			},
+			{
+				Name: "depends_on",
+			},
+		},
+		Blocks: []hcl.BlockHeaderSchema{
+			{Type: "lifecycle"},
+			{Type: "connection"},
+			{Type: "provisioner", LabelNames: []string{"type"}},
+		},
+	})
+	if diags.HasErrors() {
+		return nil, diags
+	}
+
+	var count hcl.Expression
+	if attr, exists := content.Attributes["count"]; exists {
+		count = attr.Expr
+	}
+
+	var forEach hcl.Expression
+	if attr, exists := content.Attributes["for_each"]; exists {
+		forEach = attr.Expr
+	}
+
+	var ref *terraform.ProviderConfigRef
+	if attr, exists := content.Attributes["provider"]; exists {
+		traversal, diags := hcl.AbsTraversalForExpr(attr.Expr)
+		if diags.HasErrors() {
+			return nil, diags
+		}
+
+		ref = &terraform.ProviderConfigRef{
+			Name:      traversal.RootName(),
+			NameRange: traversal[0].SourceRange(),
+		}
+
+		if len(traversal) > 1 {
+			aliasStep := traversal[1].(hcl.TraverseAttr)
+			ref.Alias = aliasStep.Name
+			ref.AliasRange = aliasStep.SourceRange().Ptr()
+		}
+	}
+
+	managed := &terraform.ManagedResource{}
+	for _, block := range content.Blocks {
+		switch block.Type {
+		case "lifecycle":
+			content, _, diags := block.Body.PartialContent(&hcl.BodySchema{
+				Attributes: []hcl.AttributeSchema{
+					{
+						Name: "create_before_destroy",
+					},
+					{
+						Name: "prevent_destroy",
+					},
+					{
+						Name: "ignore_changes",
+					},
+				},
+			})
+			if diags.HasErrors() {
+				return nil, diags
+			}
+
+			if attr, exists := content.Attributes["create_before_destroy"]; exists {
+				if diags := gohcl.DecodeExpression(attr.Expr, nil, &managed.CreateBeforeDestroy); diags.HasErrors() {
+					return nil, diags
+				}
+				managed.CreateBeforeDestroySet = true
+			}
+			if attr, exists := content.Attributes["prevent_destroy"]; exists {
+				if diags := gohcl.DecodeExpression(attr.Expr, nil, &managed.PreventDestroy); diags.HasErrors() {
+					return nil, diags
+				}
+				managed.PreventDestroySet = true
+			}
+			if attr, exists := content.Attributes["ignore_changes"]; exists {
+				if hcl.ExprAsKeyword(attr.Expr) == "all" {
+					managed.IgnoreAllChanges = true
+				}
+			}
+		case "connection":
+			managed.Connection = &terraform.Connection{
+				Config:    block.Body,
+				DeclRange: block.DefRange,
+			}
+		case "provisioner":
+			pv := &terraform.Provisioner{
+				Type:      block.Labels[0],
+				TypeRange: block.LabelRanges[0],
+				DeclRange: block.DefRange,
+				When:      terraform.ProvisionerWhenCreate,
+				OnFailure: terraform.ProvisionerOnFailureFail,
+			}
+
+			content, config, diags := block.Body.PartialContent(&hcl.BodySchema{
+				Attributes: []hcl.AttributeSchema{
+					{Name: "when"},
+					{Name: "on_failure"},
+				},
+				Blocks: []hcl.BlockHeaderSchema{
+					{Type: "connection"},
+				},
+			})
+			if diags.HasErrors() {
+				return nil, diags
+			}
+			pv.Config = config
+
+			if attr, exists := content.Attributes["when"]; exists {
+				switch hcl.ExprAsKeyword(attr.Expr) {
+				case "create":
+					pv.When = terraform.ProvisionerWhenCreate
+				case "destroy":
+					pv.When = terraform.ProvisionerWhenDestroy
+				}
+			}
+
+			if attr, exists := content.Attributes["on_failure"]; exists {
+				switch hcl.ExprAsKeyword(attr.Expr) {
+				case "continue":
+					pv.OnFailure = terraform.ProvisionerOnFailureContinue
+				case "fail":
+					pv.OnFailure = terraform.ProvisionerOnFailureFail
+				}
+			}
+
+			for _, block := range content.Blocks {
+				pv.Connection = &terraform.Connection{
+					Config:    block.Body,
+					DeclRange: block.DefRange,
+				}
+			}
+
+			managed.Provisioners = append(managed.Provisioners, pv)
+		}
+	}
+
+	return &terraform.Resource{
+		Mode:    terraform.ManagedResourceMode,
+		Name:    resource.Labels[1],
+		Type:    resource.Labels[0],
+		Config:  resourceRemain,
+		Count:   count,
+		ForEach: forEach,
+
+		ProviderConfigRef: ref,
+
+		Managed: managed,
+
+		DeclRange: resource.DefRange,
+		TypeRange: resource.LabelRanges[0],
+	}, nil
+}