macOS example uses 'iso_urls' to upload "preseed" image dynamically

examples/macos/macos-10.13.json

@@ -30,10 +30,13 @@
 
       "iso_paths": [
         "[datastore-mac] ISO/macOS 10.13.3.iso",
-        "[datastore-mac] ISO/setup.iso",
         "[datastore-mac] ISO/VMware Tools/10.2.0/darwin.iso"
       ],
 
+      "iso_urls": ["{{template_dir}}/setup/out/setup.iso"],
+      "iso_checksum_type": "sha256",
+      "iso_checksum_url": "file:///{{template_dir}}/setup/out/sha256sums",
+
       "boot_wait": "4m",
       "boot_command": [
         "<enter><wait5>",

examples/macos/setup/iso-setup.sh

@@ -23,3 +23,5 @@ productbuild --package out/postinstall.pkg out/iso/postinstall.pkg
 
 rm -f out/setup.iso
 hdiutil makehybrid -iso -joliet -default-volume-name setup -o out/setup.iso out/iso
+cd out
+shasum -a 256 setup.iso >sha256sums