Add some basic endpoints to the config app backend

rename files to avoid overlap with quay app

config_app/config_util/config/fileprovider.py

@@ -0,0 +1,60 @@
+import os
+import logging
+
+from config_util.config.baseprovider import export_yaml, CannotWriteConfigException
+from config_util.config.basefileprovider import BaseFileProvider
+
+
+logger = logging.getLogger(__name__)
+
+
+def _ensure_parent_dir(filepath):
+    """ Ensures that the parent directory of the given file path exists. """
+    try:
+        parentpath = os.path.abspath(os.path.join(filepath, os.pardir))
+        if not os.path.isdir(parentpath):
+            os.makedirs(parentpath)
+    except IOError as ioe:
+        raise CannotWriteConfigException(str(ioe))
+
+
+class FileConfigProvider(BaseFileProvider):
+    """ Implementation of the config provider that reads and writes the data
+        from/to the file system. """
+    def __init__(self, config_volume, yaml_filename, py_filename):
+        super(FileConfigProvider, self).__init__(config_volume, yaml_filename, py_filename)
+
+    @property
+    def provider_id(self):
+        return 'file'
+
+    def save_config(self, config_obj):
+        export_yaml(config_obj, self.yaml_path)
+
+    def write_volume_file(self, filename, contents):
+        filepath = os.path.join(self.config_volume, filename)
+        _ensure_parent_dir(filepath)
+
+        try:
+            with open(filepath, mode='w') as f:
+                f.write(contents)
+        except IOError as ioe:
+            raise CannotWriteConfigException(str(ioe))
+
+        return filepath
+
+    def remove_volume_file(self, filename):
+        filepath = os.path.join(self.config_volume, filename)
+        os.remove(filepath)
+
+    def save_volume_file(self, filename, flask_file):
+        filepath = os.path.join(self.config_volume, filename)
+        _ensure_parent_dir(filepath)
+
+        # Write the file.
+        try:
+            flask_file.save(filepath)
+        except IOError as ioe:
+            raise CannotWriteConfigException(str(ioe))
+
+        return filepath