Patch writefile to error when no content specified (#2388)

projects/tinkerbell/hub/CHECKSUMS

@@ -2,4 +2,4 @@
 e004f52237340707b753fd226c6c369931d9d6c1f966615d6475d4c2fd13dcf0  _output/bin/hub/linux-amd64/image2disk
 dcfec6b7c4fc2452defdaaec7a611fbe6cdf00e8e5dae86768447578849a4766  _output/bin/hub/linux-amd64/kexec
 cdf00127e3c815c792e3eb7e61fa858095a62afb98bda2714f92e463ca95f0cb  _output/bin/hub/linux-amd64/oci2disk
-abd5d9e875dcebfed9948b49e74fbaeeb1c1a8385c5cf2c7ad1c05e5a48be239  _output/bin/hub/linux-amd64/writefile
+9bbedaca313d22dd326665c84f308808bb73a593436d881b8929a887844b8ba6  _output/bin/hub/linux-amd64/writefile

projects/tinkerbell/hub/patches/0011-Ensure-content-is-specified-before-writing-file.patch

@@ -0,0 +1,36 @@
+From 5c7b24fde808e5c175df6ff9f1286b49a0f156a9 Mon Sep 17 00:00:00 2001
+From: Chris Doherty <[email protected]>
+Date: Tue, 15 Aug 2023 13:34:34 -0500
+Subject: [PATCH] Ensure content is specified before writing file
+
+---
+ actions/writefile/v1/main.go | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/actions/writefile/v1/main.go b/actions/writefile/v1/main.go
+index 954a45e..bf9f4ac 100644
+--- a/actions/writefile/v1/main.go
++++ b/actions/writefile/v1/main.go
+@@ -259,6 +259,10 @@ func main() {
+ 		}
+ 	}
+
++	if contents == "" {
++		log.Fatal("No content. Either the CONTENTS env var was not set or a data retrieval action failed.")
++	}
++
+ 	// If bootconfig is set, contents will be empty and will serve as output initrd file provided
+ 	// to bootconfig tool
+ 	fqFilePath := filepath.Join(mountAction, filePath)
+@@ -292,7 +296,7 @@ func main() {
+ }
+
+ func appendToUserData(contents string, filePath string) error {
+-	f, err := os.OpenFile(filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
++	f, err := os.OpenFile(filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
+ 	if err != nil {
+ 		return err
+ 	}
+-- 
+2.40.1
+