From 66153c6194bcc1cd7783da7bbb8ddf516227bb82 Mon Sep 17 00:00:00 2001
From: Marcos Lilljedahl <marcosnils@gmail.com>
Date: Thu, 31 Mar 2022 19:31:14 -0300
Subject: [PATCH] Prevents files to be used as input of dagger.#FS

Errors out in the PreRun phase of the clientfilesystemreader task since
otherwise, dagger execution would hang
Fixes #1977

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>
---
 plan/task/clientfilesystemread.go                     |  7 ++++---
 tests/plan.bats                                       |  9 +++++++++
 tests/plan/client/filesystem/read/fs/invalid/test.cue | 11 +++++++++++
 3 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 tests/plan/client/filesystem/read/fs/invalid/test.cue

diff --git a/plan/task/clientfilesystemread.go b/plan/task/clientfilesystemread.go
index 0ec37f1a..6ef5a32d 100644
--- a/plan/task/clientfilesystemread.go
+++ b/plan/task/clientfilesystemread.go
@@ -18,8 +18,7 @@ func init() {
 	Register("ClientFilesystemRead", func() Task { return &clientFilesystemReadTask{} })
 }
 
-type clientFilesystemReadTask struct {
-}
+type clientFilesystemReadTask struct{}
 
 func (t clientFilesystemReadTask) PreRun(_ context.Context, pctx *plancontext.Context, v *compiler.Value) error {
 	path, err := t.parsePath(v)
@@ -27,8 +26,10 @@ func (t clientFilesystemReadTask) PreRun(_ context.Context, pctx *plancontext.Co
 		return err
 	}
 
-	if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
+	if pi, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
 		return fmt.Errorf("path %q does not exist", path)
+	} else if !pi.IsDir() && plancontext.IsFSValue(v.Lookup("contents")) {
+		return fmt.Errorf("path %q is not a directory", path)
 	}
 
 	if plancontext.IsFSValue(v.Lookup("contents")) {
diff --git a/tests/plan.bats b/tests/plan.bats
index c783daa9..78a6cc66 100644
--- a/tests/plan.bats
+++ b/tests/plan.bats
@@ -84,6 +84,15 @@ setup() {
   assert_output --partial 'path "/foobar" does not exist'
 }
 
+
+@test "plan/client/filesystem/read/fs/invalid" {
+  cd "$TESTDIR/plan/client/filesystem/read/fs/invalid"
+
+  run "$DAGGER" "do" -p . test
+  assert_failure
+  assert_output --partial 'test.txt" is not a directory'
+}
+
 @test "plan/client/filesystem/read/fs/relative" {
   cd "$TESTDIR/plan/client/filesystem/read/fs/relative"
 
diff --git a/tests/plan/client/filesystem/read/fs/invalid/test.cue b/tests/plan/client/filesystem/read/fs/invalid/test.cue
new file mode 100644
index 00000000..155203eb
--- /dev/null
+++ b/tests/plan/client/filesystem/read/fs/invalid/test.cue
@@ -0,0 +1,11 @@
+package main
+
+import (
+	"dagger.io/dagger"
+)
+
+dagger.#Plan & {
+	client: filesystem: "../rootfs/test.txt": read: contents: dagger.#FS
+	actions: test: {
+	}
+}