file_util generate_config -> generate_config_yaml

The two usages of generate_config were both for yaml, so make that
simpler.

subiquity/server/apt.py

@@ -21,9 +21,7 @@ import tempfile
 
 from curtin.config import merge_config
 
-import yaml
-
-from subiquitycore.file_util import write_file, generate_config
+from subiquitycore.file_util import write_file, generate_config_yaml
 from subiquitycore.lsb_release import lsb_release
 from subiquitycore.utils import arun_command
 
@@ -179,7 +177,7 @@ class AptConfigurer:
 
         config_location = os.path.join(
             self.app.root, 'var/log/installer/subiquity-curtin-apt.conf')
-        generate_config(config_location, yaml.dump(self.apt_config()))
+        generate_config_yaml(config_location, self.apt_config())
         self.app.note_data_for_apport("CurtinAptConfig", config_location)
 
         await run_curtin_command(

subiquity/server/controllers/install.py

@@ -29,7 +29,7 @@ from subiquitycore.async_helpers import (
     run_in_thread,
     )
 from subiquitycore.context import with_context
-from subiquitycore.file_util import write_file, generate_config
+from subiquitycore.file_util import write_file, generate_config_yaml
 
 from subiquity.common.errorreport import ErrorReportKind
 from subiquity.common.types import (
@@ -106,7 +106,7 @@ class InstallController(SubiquityController):
             log_location = self.app.opts.output_base + INSTALL_LOG
         os.makedirs(os.path.dirname(config_location), exist_ok=True)
         os.makedirs(os.path.dirname(log_location), exist_ok=True)
-        generate_config(config_location, yaml.dump(config))
+        generate_config_yaml(config_location, config)
         self.app.note_file_for_apport("CurtinConfig", config_location)
         self.app.note_file_for_apport("CurtinErrors", ERROR_TARFILE)
         self.app.note_file_for_apport("CurtinLog", log_location)

subiquitycore/file_util.py

@@ -20,6 +20,8 @@ import os
 import stat
 import tempfile
 
+import yaml
+
 _DEF_PERMS = 0o640
 _DEF_GROUP = 'adm'
 
@@ -60,8 +62,8 @@ def write_file(filename, content, **kwargs):
         tf.write(content)
 
 
-def generate_config(filename, content, **kwargs):
+def generate_config_yaml(filename, content, **kwargs):
     with open_perms(filename, **kwargs) as tf:
         now = datetime.datetime.utcnow()
         tf.write(f'# Autogenerated by Subiquity: {now} UTC\n')
-        tf.write(content)
+        tf.write(yaml.dump(content))