63 lines
2.2 KiB
Python
63 lines
2.2 KiB
Python
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import os
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from shutil import copytree
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from backports.tempfile import TemporaryDirectory
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from config_app.config_util.config.fileprovider import FileConfigProvider
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OLD_CONFIG_SUBDIR = 'old/'
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class TransientDirectoryProvider(FileConfigProvider):
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""" Implementation of the config provider that reads and writes the data
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from/to the file system, only using temporary directories,
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deleting old dirs and creating new ones as requested.
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"""
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def __init__(self, config_volume, yaml_filename, py_filename):
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# Create a temp directory that will be cleaned up when we change the config path
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# This should ensure we have no "pollution" of different configs:
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# no uploaded config should ever affect subsequent config modifications/creations
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temp_dir = TemporaryDirectory()
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self.temp_dir = temp_dir
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self.old_config_dir = None
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super(TransientDirectoryProvider, self).__init__(temp_dir.name, yaml_filename, py_filename)
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@property
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def provider_id(self):
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return 'transient'
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def new_config_dir(self):
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"""
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Update the path with a new temporary directory, deleting the old one in the process
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"""
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self.temp_dir.cleanup()
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temp_dir = TemporaryDirectory()
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self.config_volume = temp_dir.name
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self.temp_dir = temp_dir
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self.yaml_path = os.path.join(temp_dir.name, self.yaml_filename)
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def create_copy_of_config_dir(self):
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"""
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Create a directory to store loaded/populated configuration (for rollback if necessary)
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"""
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if self.old_config_dir is not None:
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self.old_config_dir.cleanup()
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temp_dir = TemporaryDirectory()
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self.old_config_dir = temp_dir
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# Python 2.7's shutil.copy() doesn't allow for copying to existing directories,
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# so when copying/reading to the old saved config, we have to talk to a subdirectory,
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# and use the shutil.copytree() function
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copytree(self.config_volume, os.path.join(temp_dir.name, OLD_CONFIG_SUBDIR))
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def get_config_dir_path(self):
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return self.config_volume
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def get_old_config_dir(self):
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if self.old_config_dir is None:
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raise Exception('Cannot return a configuration that was no old configuration')
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return os.path.join(self.old_config_dir.name, OLD_CONFIG_SUBDIR)
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