Source code for ansible_runner.loader
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import os
import json
from yaml import safe_load, YAMLError
from six import string_types
from ansible_runner.exceptions import ConfigurationError
from ansible_runner.output import debug
[docs]class ArtifactLoader(object):
'''
Handles loading and caching file contents from disk
This class will load the file contents and attempt to deserialize the
contents as either JSON or YAML. If the file contents cannot be
deserialized, the contents will be returned to the caller as a string.
The deserialized file contents are stored as a cached object in the
instance to avoid any additional reads from disk for subsequent calls
to load the same file.
'''
def __init__(self, base_path):
self._cache = {}
self.base_path = base_path
def _load_json(self, contents):
'''
Attempts to deserialize the contents of a JSON object
Args:
contents (string): The contents to deserialize
Returns:
dict: If the contents are JSON serialized
None: If the contents are not JSON serialized
'''
try:
return json.loads(contents)
except ValueError:
pass
def _load_yaml(self, contents):
'''
Attempts to deserialize the contents of a YAML object
Args:
contents (string): The contents to deserialize
Returns:
dict: If the contents are YAML serialized
None: If the contents are not YAML serialized
'''
try:
return safe_load(contents)
except YAMLError as exc:
pass
[docs] def get_contents(self, path):
'''
Loads the contents of the file specified by path
Args:
path (string): The relative or absolute path to the file to
be loaded. If the path is relative, then it is combined
with the base_path to generate a full path string
Returns:
string: The contents of the file as a string
Raises:
ConfigurationError: If the file cannot be loaded
'''
try:
if not os.path.exists(path):
raise ConfigurationError('specified path does not exist %s' % path)
with open(path) as f:
data = f.read()
return data
except (IOError, OSError) as exc:
raise ConfigurationError('error trying to load file contents: %s' % exc)
[docs] def abspath(self, path):
'''
Transform the path to an absolute path
Args:
path (string): The path to transform to an absolute path
Returns:
string: The absolute path to the file
'''
if not path.startswith(os.path.sep) or path.startswith('~'):
path = os.path.expanduser(os.path.join(self.base_path, path))
return path
[docs] def isfile(self, path):
'''
Check if the path is a file
:params path: The path to the file to check. If the path is relative
it will be exanded to an absolute path
:returns: boolean
'''
return os.path.isfile(self.abspath(path))
[docs] def load_file(self, path, objtype=None, encoding='utf-8'):
'''
Load the file specified by path
This method will first try to load the file contents from cache and
if there is a cache miss, it will load the contents from disk
Args:
path (string): The full or relative path to the file to be loaded
encoding (string): The file contents text encoding
objtype (object): The object type of the file contents. This
is used to type check the deserialized content against the
contents loaded from disk.
Ignore serializing if objtype is string_types
Returns:
object: The deserialized file contents which could be either a
string object or a dict object
Raises:
ConfigurationError:
'''
path = self.abspath(path)
debug('file path is %s' % path)
if path in self._cache:
return self._cache[path]
try:
debug('cache miss, attempting to load file from disk: %s' % path)
contents = self.get_contents(path)
parsed_data = contents.encode(encoding)
except ConfigurationError as exc:
debug(exc)
raise
except UnicodeEncodeError as exc:
raise ConfigurationError('unable to encode file contents')
if objtype is not string_types:
for deserializer in (self._load_json, self._load_yaml):
parsed_data = deserializer(contents)
if parsed_data:
break
if objtype and not isinstance(parsed_data, objtype):
debug('specified file %s is not of type %s' % (path, objtype))
raise ConfigurationError('invalid file serialization type for contents')
self._cache[path] = parsed_data
return parsed_data