org.osbuild.grub2.iso.legacy: Add support for optional fips menu

On RHEL 9.7+ and on RHEL 10.1+ we need to be able to include a menu that
boots the installer environment with fips=1 on the cmdline. This adds an
optional menu entry controlled by the "fips" boolean.

This also includes a test for the new behavior.

Related: RHEL-104075

stages/org.osbuild.grub2.iso.legacy

@@ -34,6 +34,7 @@ menuentry 'Test this media & install ${product} ${version}' --class fedora --cla
 	linux ${kernelpath} ${root} rd.live.check quiet
 	initrd ${initrdpath}
 }
+$fipsentry
 submenu 'Troubleshooting -->' {
 	menuentry 'Install ${product} ${version} in basic graphics mode' --class fedora --class gnu-linux --class gnu --class os {
 		linux ${kernelpath} ${root} nomodeset quiet
@@ -49,6 +50,14 @@ submenu 'Troubleshooting -->' {
 }
 """
 
+# Optional FIPS menu entry
+FIPS_ENTRY_TEMPLATE = """
+menuentry 'Install ${product} ${version} in FIPS mode' --class fedora --class gnu-linux --class gnu --class os {
+	linux ${kernelpath} ${root} quiet fips=1
+	initrd ${initrdpath}
+}
+"""
+
 
 def main(root, options):
     name = options["product"]["name"]
@@ -58,6 +67,7 @@ def main(root, options):
     kopts = options["kernel"].get("opts")
     cfg = options.get("config", {})
     timeout = cfg.get("timeout", 60)
+    fips = options.get("fips", False)
 
     grub2dir = os.path.join(root, "boot", "grub2")
     os.makedirs(grub2dir, exist_ok=True)
@@ -67,17 +77,25 @@ def main(root, options):
     shutil.copytree("/usr/lib/grub/i386-pc", moduledir, dirs_exist_ok=True)
 
     print(f"kernel dir at {kdir}")
-
-    tplt = string.Template(GRUB2_CFG_TEMPLATE)
-    data = tplt.safe_substitute({
+    tplt_variables = {
         "version": version,
         "product": name,
         "kernelpath": os.path.join(kdir, "vmlinuz"),
         "initrdpath": os.path.join(kdir, "initrd.img"),
         "isolabel": isolabel,
         "root": " ".join(kopts),
-        "timeout": timeout
-    })
+        "timeout": timeout,
+        "fipsentry": ""
+    }
+
+    # Insert optional fips menu entry
+    if fips:
+        fips_tmpl = string.Template(FIPS_ENTRY_TEMPLATE)
+        fipsentry = fips_tmpl.safe_substitute(tplt_variables)
+        tplt_variables["fipsentry"] = fipsentry
+
+    tplt = string.Template(GRUB2_CFG_TEMPLATE)
+    data = tplt.safe_substitute(tplt_variables)
 
     config = os.path.join(grub2dir, "grub.cfg")
     with open(config, "w", encoding="utf8") as cfg:

stages/org.osbuild.grub2.iso.legacy.meta.json

@@ -47,6 +47,9 @@
         "isolabel": {
           "type": "string"
         },
+        "fips": {
+          "type": "boolean"
+        },
         "config": {
           "description": "Configuration options for grub itself",
           "type": "object",

stages/test/test_grub2_iso_legacy.py

@@ -7,7 +7,7 @@ import pytest
 
 STAGE_NAME = "org.osbuild.grub2.iso.legacy"
 
-expected_grub_cfg = """
+CONFIG_PART_1 = """
 function load_video {
   insmod all_video
 }
@@ -33,6 +33,9 @@ menuentry 'Test this media & install Fedora-IoT 41' --class fedora --class gnu-l
 	linux /images/pxeboot/vmlinuz inst.ks=hd:LABEL=Fedora-41-X86_64:/install.ks rd.live.check quiet
 	initrd /images/pxeboot/initrd.img
 }
+"""
+
+CONFIG_PART_2 = """
 submenu 'Troubleshooting -->' {
 	menuentry 'Install Fedora-IoT 41 in basic graphics mode' --class fedora --class gnu-linux --class gnu --class os {
 		linux /images/pxeboot/vmlinuz inst.ks=hd:LABEL=Fedora-41-X86_64:/install.ks nomodeset quiet
@@ -48,9 +51,22 @@ submenu 'Troubleshooting -->' {
 }
 """
 
+CONFIG_FIPS = """
+menuentry 'Install Fedora-IoT 41 in FIPS mode' --class fedora --class gnu-linux --class gnu --class os {
+	linux /images/pxeboot/vmlinuz inst.ks=hd:LABEL=Fedora-41-X86_64:/install.ks quiet fips=1
+	initrd /images/pxeboot/initrd.img
+}
+"""
+
 
 @patch("shutil.copytree")
-def test_grub2_iso_legacy_smoke(mocked_copytree, tmp_path, stage_module):
+@pytest.mark.parametrize("test_data,expected_conf", [
+    # default
+    ({}, CONFIG_PART_1 + CONFIG_PART_2),
+    # fips menu enable
+    ({"fips": True}, CONFIG_PART_1 + CONFIG_FIPS + CONFIG_PART_2)
+])
+def test_grub2_iso_legacy_smoke(mocked_copytree, tmp_path, stage_module, test_data, expected_conf):
     treedir = tmp_path / "tree"
     confpath = treedir / "boot/grub2/grub.cfg"
     confpath.parent.mkdir(parents=True, exist_ok=True)
@@ -72,11 +88,12 @@ def test_grub2_iso_legacy_smoke(mocked_copytree, tmp_path, stage_module):
             "timeout": 10,
         }
     }
+    options.update(test_data)
 
     stage_module.main(treedir, options)
 
     assert os.path.exists(confpath)
-    assert confpath.read_text() == expected_grub_cfg
+    assert confpath.read_text() == expected_conf
     assert mocked_copytree.call_args_list == [
         call("/usr/lib/grub/i386-pc", os.fspath(treedir / "boot/grub2/i386-pc"),
              dirs_exist_ok=True),
@@ -120,6 +137,20 @@ def test_grub2_iso_legacy_smoke(mocked_copytree, tmp_path, stage_module):
             },
         }, "",
     ),
+    # good + fips
+    (
+        {
+            "isolabel": "an-isolabel",
+            "product": {
+                "name": "a-name",
+                "version": "a-version",
+            },
+            "kernel": {
+                "dir": "/path/to",
+            },
+            "fips": True,
+        }, "",
+    ),
 ])
 def test_schema_validation(stage_schema, test_data, expected_err):
     test_input = {