lorax-composer: pass customization.kernel append to extra_boot_args

This allows iso builds to include the extra kernel boot parameters by
passing them to the arch-specific live/*tmpl template.

Also adds tests to make sure it is written to config.toml in the build
metadata.

Resolves: rhbz#1687743

src/pylorax/api/compose.py

@@ -142,6 +142,21 @@ def bootloader_append(line, kernel_append):
     return str(ks.handler.bootloader).splitlines()[-1]
 
 
+def get_kernel_append(recipe):
+    """Return the customizations.kernel append value
+
+    :param recipe:
+    :type recipe: Recipe object
+    :returns: append value or empty string
+    :rtype: str
+    """
+    if "customizations" not in recipe or \
+       "kernel" not in recipe["customizations"] or \
+       "append" not in recipe["customizations"]["kernel"]:
+        return ""
+    return recipe["customizations"]["kernel"]["append"]
+
+
 def customize_ks_template(ks_template, recipe):
     """ Customize the kickstart template and return it
 
@@ -153,11 +168,9 @@ def customize_ks_template(ks_template, recipe):
     Apply customizations.kernel.append to the bootloader argument in the template.
     Add bootloader line if it is missing.
     """
-    if "customizations" not in recipe or \
-       "kernel" not in recipe["customizations"] or \
-       "append" not in recipe["customizations"]["kernel"]:
+    kernel_append = get_kernel_append(recipe)
+    if not kernel_append:
         return ks_template
-    kernel_append = recipe["customizations"]["kernel"]["append"]
     found_bootloader = False
     output = StringIO()
     for line in ks_template.splitlines():
@@ -520,6 +533,7 @@ def start_build(cfg, dnflock, gitlock, branch, recipe_name, compose_type, test_m
     cfg_args["project"] = os_release.get("NAME", "")
     cfg_args["releasever"] = os_release.get("VERSION_ID", "")
     cfg_args["volid"] = ""
+    cfg_args["extra_boot_args"] = get_kernel_append(recipe)
 
     cfg_args.update({
         "compression":      "xz",

tests/pylorax/test_server.py

@@ -1078,6 +1078,12 @@ class ServerTestCase(unittest.TestCase):
         self.assertTrue("network --hostname=" in final_ks)
         self.assertTrue("sshkey --user root" in final_ks)
 
+        # Examine the config.toml to make sure it has an empty extra_boot_args
+        cfg_path = joinpaths(self.repo_dir, "var/lib/lorax/composer/results/", build_id, "config.toml")
+        cfg_dict = toml.loads(open(cfg_path, "r").read())
+        self.assertTrue("extra_boot_args" in cfg_dict)
+        self.assertEqual(cfg_dict["extra_boot_args"], "")
+
         # Delete the finished build
         # Test the /api/v0/compose/delete/<uuid> route
         resp = self.server.delete("/api/v0/compose/delete/%s" % build_id)
@@ -1231,6 +1237,12 @@ class ServerTestCase(unittest.TestCase):
         self.assertNotEqual(bootloader_line, "", "No bootloader line found")
         self.assertTrue("nosmt=force" in bootloader_line)
 
+        # Examine the config.toml to make sure it was written there as well
+        cfg_path = joinpaths(self.repo_dir, "var/lib/lorax/composer/results/", build_id, "config.toml")
+        cfg_dict = toml.loads(open(cfg_path, "r").read())
+        self.assertTrue("extra_boot_args" in cfg_dict)
+        self.assertEqual(cfg_dict["extra_boot_args"], "nosmt=force")
+
     def assertInputError(self, resp):
         """Check all the conditions for a successful input check error result"""
         data = json.loads(resp.data)