improve Terraform scanning logging

Signed-off-by: nikpivkin <[email protected]>

pkg/iac/scanners/terraform/parser/evaluator.go

@@ -125,22 +125,39 @@ func (e *evaluator) exportOutputs() cty.Value {
 
 func (e *evaluator) EvaluateAll(ctx context.Context) (terraform.Modules, map[string]fs.FS) {
 
-	fsKey := types.CreateFSKey(e.filesystem)
+	e.logger.Debug("Starting module evaluation...", log.String("path", e.modulePath))
 
-	fsMap := make(map[string]fs.FS)
-	fsMap[fsKey] = e.filesystem
+	fsKey := types.CreateFSKey(e.filesystem)
+	fsMap := map[string]fs.FS{
+		fsKey: e.filesystem,
+	}
 
-	e.logger.Debug("Starting module evaluation...")
 	e.evaluateSteps()
 
 	// expand out resources and modules via count, for-each and dynamic
 	// (not a typo, we do this twice so every order is processed)
 	e.blocks = e.expandBlocks(e.blocks)
 	e.blocks = e.expandBlocks(e.blocks)
 
-	e.logger.Debug("Starting submodule evaluation...")
+	submodules := e.evaluateSubmodules(ctx, fsMap)
+
+	e.logger.Debug("Starting post-submodules evaluation...")
+	e.evaluateSteps()
+
+	e.logger.Debug("Module evaluation complete.")
+	rootModule := terraform.NewModule(e.projectRootPath, e.modulePath, e.blocks, e.ignores)
+	return append(terraform.Modules{rootModule}, submodules...), fsMap
+}
+
+func (e *evaluator) evaluateSubmodules(ctx context.Context, fsMap map[string]fs.FS) terraform.Modules {
 	submodules := e.loadSubmodules(ctx)
 
+	if len(submodules) == 0 {
+		return nil
+	}
+
+	e.logger.Debug("Starting submodules evaluation...")
+
 	for i := 0; i < maxContextIterations; i++ {
 		changed := false
 		for _, sm := range submodules {
@@ -162,9 +179,7 @@ func (e *evaluator) EvaluateAll(ctx context.Context) (terraform.Modules, map[str
 	}
 
 	e.logger.Debug("Finished processing submodule(s).", log.Int("count", len(modules)))
-	e.logger.Debug("Module evaluation complete.")
-	rootModule := terraform.NewModule(e.projectRootPath, e.modulePath, e.blocks, e.ignores)
-	return append(terraform.Modules{rootModule}, modules...), fsMap
+	return modules
 }
 
 type submodule struct {
@@ -285,6 +300,7 @@ func isBlockSupportsForEachMetaArgument(block *terraform.Block) bool {
 }
 
 func (e *evaluator) expandBlockForEaches(blocks terraform.Blocks, isDynamic bool) terraform.Blocks {
+
 	var forEachFiltered terraform.Blocks
 
 	for _, block := range blocks {
@@ -299,6 +315,10 @@ func (e *evaluator) expandBlockForEaches(blocks terraform.Blocks, isDynamic bool
 		forEachVal := forEachAttr.Value()
 
 		if forEachVal.IsNull() || !forEachVal.IsKnown() || !forEachAttr.IsIterable() {
+			e.logger.Error(`Failed to expand block. Invalid "for-each" argument. Must be known and iterable.`,
+				log.String("block", block.FullName()),
+				log.String("value", forEachVal.GoString()),
+			)
 			continue
 		}
 
@@ -313,7 +333,7 @@ func (e *evaluator) expandBlockForEaches(blocks terraform.Blocks, isDynamic bool
 			idx, err := convert.Convert(key, cty.String)
 			if err != nil {
 				e.logger.Error(
-					`Invalid "for-each" argument: map key (or set value) is not a string`,
+					`Failed to expand block. Invalid "for-each" argument: map key (or set value) is not a string`,
 					log.String("block", block.FullName()),
 					log.String("key", key.GoString()),
 					log.String("value", val.GoString()),
@@ -330,7 +350,7 @@ func (e *evaluator) expandBlockForEaches(blocks terraform.Blocks, isDynamic bool
 				stringVal, err := convert.Convert(val, cty.String)
 				if err != nil {
 					e.logger.Error(
-						"Failed to convert for-each arg to string",
+						"Failed to expand block. Invalid 'for-each' argument: value is not a string",
 						log.String("block", block.FullName()),
 						log.String("key", idx.AsString()),
 						log.String("value", val.GoString()),
@@ -360,7 +380,8 @@ func (e *evaluator) expandBlockForEaches(blocks terraform.Blocks, isDynamic bool
 						ctx.Set(idx, refs[0].TypeLabel(), "key")
 						ctx.Set(val, refs[0].TypeLabel(), "value")
 					} else {
-						e.logger.Debug("Ignoring iterator attribute in dynamic block, expected one reference", log.Int("refs", len(refs)))
+						e.logger.Debug("Ignoring iterator attribute in dynamic block, expected one reference",
+							log.Int("refs", len(refs)))
 					}
 				}
 			}
@@ -424,7 +445,7 @@ func (e *evaluator) expandBlockCounts(blocks terraform.Blocks) terraform.Blocks
 			e.ctx.SetByDot(cty.TupleVal(clones), metadata.Reference())
 		}
 		e.logger.Debug(
-			"Expanded block '%s' into %d clones via 'count' attribute.",
+			"Expanded block into clones via 'count' attribute.",
 			log.String("block", block.FullName()),
 			log.Int("clones", len(clones)),
 		)

pkg/iac/scanners/terraform/parser/load_module.go

@@ -78,7 +78,7 @@ func (e *evaluator) loadModule(ctx context.Context, b *terraform.Block) (*Module
 	}
 
 	if def, err := e.loadModuleFromTerraformCache(ctx, b, source); err == nil {
-		e.logger.Debug("found module in .terraform/modules", log.String("source", source))
+		e.logger.Debug("Using module from Terraform cache .terraform/modules", log.String("source", source))
 		return def, nil
 	}
 

pkg/iac/scanners/terraform/parser/parser.go

@@ -161,7 +161,7 @@ func (p *Parser) ParseFS(ctx context.Context, dir string) error {
 			if p.stopOnHCLError {
 				return err
 			}
-			p.logger.Error("Error parsing", log.FilePath(path), log.Err(err))
+			p.logger.Error("Error parsing file", log.FilePath(path), log.Err(err))
 			continue
 		}
 	}
@@ -172,7 +172,7 @@ func (p *Parser) ParseFS(ctx context.Context, dir string) error {
 var ErrNoFiles = errors.New("no files found")
 
 func (p *Parser) Load(ctx context.Context) (*evaluator, error) {
-	p.logger.Debug("Evaluating module...")
+	p.logger.Debug("Loading module", log.String("module", p.moduleName))
 
 	if len(p.files) == 0 {
 		p.logger.Info("No files found, nothing to do.")
@@ -197,6 +197,17 @@ func (p *Parser) Load(ctx context.Context) (*evaluator, error) {
 			return nil, err
 		}
 		p.logger.Debug("Added input variables from tfvars", log.Int("count", len(inputVars)))
+
+		for _, varBlock := range blocks.OfType("variable") {
+			if varBlock.GetAttribute("default") == nil {
+				if _, ok := inputVars[varBlock.TypeLabel()]; !ok {
+					p.logger.Warn(
+						"Variable was not found in the environment or variable files. Evaluating may not work correctly.",
+						log.String("variable", varBlock.TypeLabel()),
+					)
+				}
+			}
+		}
 	}
 
 	modulesMetadata, metadataPath, err := loadModuleMetadata(p.moduleFS, p.projectRoot)

pkg/iac/scanners/terraform/scanner.go

@@ -152,7 +152,7 @@ func (s *Scanner) ScanFS(ctx context.Context, target fs.FS, dir string) (scan.Re
 	sort.Strings(modulePaths)
 
 	if len(modulePaths) == 0 {
-		s.logger.Info("No modules found, skipping scanning")
+		s.logger.Info("No modules found, skipping directory", log.FilePath(dir))
 		return nil, nil
 	}