Merge pull request #952 from thaJeztah/18.09_backport_fix_empty_docke…

…rfile [18.09 backport] Have parser error on dockerfiles without instructions
moby · Apr 20, 2019 · 05766c5 · 05766c5
2 parents ed4da8b + 045e3a2
commit 05766c5
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diff --git a/frontend/dockerfile/parser/parser.go b/frontend/dockerfile/parser/parser.go
@@ -275,6 +275,11 @@ func Parse(rwc io.Reader) (*Result, error) {
 	if len(warnings) > 0 {
 		warnings = append(warnings, "[WARNING]: Empty continuation lines will become errors in a future release.")
 	}
+
+	if root.StartLine < 0 {
+		return nil, errors.New("file with no instructions.")
+	}
+
 	return &Result{
 		AST:         root,
 		Warnings:    warnings,

diff --git a/frontend/dockerfile/parser/testfiles-negative/empty_dockerfile/Dockerfile b/frontend/dockerfile/parser/testfiles-negative/empty_dockerfile/Dockerfile
diff --git a/frontend/dockerfile/parser/testfiles-negative/only_comments/Dockerfile b/frontend/dockerfile/parser/testfiles-negative/only_comments/Dockerfile
@@ -0,0 +1,3 @@
+# Hello
+# These are just comments
+