Source code for datalad.config

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#   See COPYING file distributed along with the datalad package for the
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"""
"""

import datalad
from datalad.cmd import GitRunner
from datalad.dochelpers import exc_str
from distutils.version import LooseVersion

import re
import os
from os.path import join as opj, exists
from os.path import getmtime
from os.path import abspath
from time import time

cfg_kv_regex = re.compile(r'(^.*)\n(.*)$', flags=re.MULTILINE)
cfg_section_regex = re.compile(r'(.*)\.[^.]+')
cfg_sectionoption_regex = re.compile(r'(.*)\.([^.]+)')


_where_reload_doc = """
        where : {'dataset', 'local', 'global'}, optional
          Indicator which configuration file to modify. 'dataset' indicates the
          persistent configuration in .datalad/config of a dataset; 'local'
          the configuration of a dataset's Git repository in .git/config;
          'global' refers to the general configuration that is not specific to
          a single repository (usually in $USER/.gitconfig).
        reload : bool
          Flag whether to reload the configuration from file(s) after
          modification. This can be disable to make multiple sequential
          modifications slightly more efficient.""".lstrip()


# we cannot import external_versions here, as the cfg comes before anything
# and we would have circular imports
[docs]def get_git_version(runner): """Return version of available git""" return runner.run('git version'.split())[0].split()[2]
def _where_reload(obj): """Helper decorator to simplify providing repetitive docstring""" obj.__doc__ = obj.__doc__ % _where_reload_doc return obj def _parse_gitconfig_dump(dump, store, fileset, replace): if replace: # if we want to replace existing values in the store # collect into a new dict and `update` the store at the # end. This way we get the desired behavior of multi-value # keys, but only for the current source dct = {} fileset = set() else: # if we don't want to replace value, perform the multi-value # preserving addition on the existing store right away dct = store for line in dump.split('\0'): if not line: continue if line.startswith('file:'): # origin line fileset.add(abspath(line[5:])) continue if line.startswith('command line:'): # nothing we could handle continue k, v = cfg_kv_regex.match(line).groups() present_v = dct.get(k, None) if present_v is None: dct[k] = v else: if isinstance(present_v, tuple): dct[k] = present_v + (v,) else: dct[k] = (present_v, v) if replace: store.update(dct) return store, fileset def _parse_env(store): dct = {} for k in os.environ: if not k.startswith('DATALAD_'): continue dct[k.replace('__', '-').replace('_', '.').lower()] = os.environ[k] store.update(dct) return store
[docs]def anything2bool(val): if hasattr(val, 'lower'): val = val.lower() if val in {"off", "no", "false", "0"} or not bool(val): return False elif val in {"on", "yes", "true", True} \ or (hasattr(val, 'isdigit') and val.isdigit() and int(val)) \ or isinstance(val, int) and val: return True else: raise TypeError( "Got value %s which could not be interpreted as a boolean" % repr(val))
[docs]class ConfigManager(object): """Thin wrapper around `git-config` with support for a dataset configuration. The general idea is to have an object that is primarily used to read/query configuration option. Upon creation, current configuration is read via one (or max two, in the case of the presence of dataset-specific configuration) calls to `git config`. If this class is initialized with a Dataset instance, it supports reading and writing configuration from ``.datalad/config`` inside a dataset too. This file is committed to Git and hence useful to ship certain configuration items with a dataset. The API aims to provide the most significant read-access API of a dictionary, the Python ConfigParser, and GitPython's config parser implementations. This class is presently not capable of efficiently writing multiple configurations items at once. Instead, each modification results in a dedicated call to `git config`. This author thinks this is OK, as he cannot think of a situation where a large number of items need to be written during normal operation. If such need arises, various solutions are possible (via GitPython, or an independent writer). Each instance carries a public `overrides` attribute. This dictionary contains variables that override any setting read from a file. The overrides are persistent across reloads, and are not modified by any of the manipulation methods, such as `set` or `unset`. Any DATALAD_* environment variable is also presented as a configuration item. Settings read from environment variables are not stored in any of the configuration file, but are read dynamically from the environment at each `reload()` call. Their values take precedence over any specification in configuration files, and even overrides. Parameters ---------- dataset : Dataset, optional If provided, all `git config` calls are executed in this dataset's directory. Moreover, any modifications are, by default, directed to this dataset's configuration file (which will be created on demand) dataset_only : bool If True, configuration items are only read from a datasets persistent configuration file, if any present (the one in ``.datalad/config``, not ``.git/config``). overrides : dict, optional Variable overrides, see general class documentation for details. """ def __init__(self, dataset=None, dataset_only=False, overrides=None): # store in a simple dict # no subclassing, because we want to be largely read-only, and implement # config writing separately self._store = {} self._cfgfiles = set() self._cfgmtimes = None # public dict to store variables that always override any setting # read from a file # `hasattr()` is needed because `datalad.cfg` is generated upon first module # import, hence when this code runs first, there cannot be any config manager # to inherit from self.overrides = datalad.cfg.overrides.copy() if hasattr(datalad, 'cfg') else {} if overrides is not None: self.overrides.update(overrides) if dataset is None: self._dataset_path = None self._dataset_cfgfname = None self._repo_cfgfname = None else: self._dataset_path = dataset.path self._dataset_cfgfname = opj(self._dataset_path, '.datalad', 'config') if not dataset_only: self._repo_cfgfname = opj(self._dataset_path, '.git', 'config') self._dataset_only = dataset_only # Since configs could contain sensitive information, to prevent # any "facilitated" leakage -- just disable logging of outputs for # this runner run_kwargs = dict(log_outputs=False) if dataset is not None: # make sure we run the git config calls in the dataset # to pick up the right config files run_kwargs['cwd'] = dataset.path self._runner = GitRunner(**run_kwargs) try: self._gitconfig_has_showorgin = \ LooseVersion(get_git_version(self._runner)) >= '2.8.0' except: # no git something else broken, assume git is present anyway # to not delay this, but assume it is old self._gitconfig_has_showorgin = False self.reload(force=True)
[docs] def reload(self, force=False): """Reload all configuration items from the configured sources If `force` is False, all files configuration was previously read from are checked for differences in the modification times. If no difference is found for any file no reload is performed. This mechanism will not detect newly created global configuration files, use `force` in this case. """ if not force and self._cfgmtimes: # we aren't forcing and we have read files before # check if any file we read from has changed current_time = time() curmtimes = {c: getmtime(c) for c in self._cfgfiles if exists(c)} if all(curmtimes[c] == self._cfgmtimes.get(c) and # protect against low-res mtimes (FAT32 has 2s, EXT3 has 1s!) # if mtime age is less than worst resolution assume modified (current_time - curmtimes[c]) > 2.0 for c in curmtimes): # all the same, nothing to do, except for # superimpose overrides, could have changed in the meantime self._store.update(self.overrides) # reread env, is quick self._store = _parse_env(self._store) return self._store = {} # 2-step strategy: # - load datalad dataset config from dataset # - load git config from all supported by git sources # in doing so we always stay compatible with where Git gets its # config from, but also allow to override persistent information # from dataset locally or globally run_args = ['-z', '-l'] if self._gitconfig_has_showorgin: run_args.append('--show-origin') if self._dataset_cfgfname: if exists(self._dataset_cfgfname): stdout, stderr = self._run( run_args + ['--file', self._dataset_cfgfname], log_stderr=True ) # overwrite existing value, do not amend to get multi-line # values self._store, self._cfgfiles = _parse_gitconfig_dump( stdout, self._store, self._cfgfiles, replace=False) if self._dataset_only: # superimpose overrides self._store.update(self.overrides) return stdout, stderr = self._run(run_args, log_stderr=True) self._store, self._cfgfiles = _parse_gitconfig_dump( stdout, self._store, self._cfgfiles, replace=True) # always monitor the dataset cfg location, we know where it is in all cases if self._dataset_cfgfname: self._cfgfiles.add(self._dataset_cfgfname) self._cfgfiles.add(self._repo_cfgfname) self._cfgmtimes = {c: getmtime(c) for c in self._cfgfiles if exists(c)} # superimpose overrides self._store.update(self.overrides) # override with environment variables self._store = _parse_env(self._store)
[docs] @_where_reload def obtain(self, var, default=None, dialog_type=None, valtype=None, store=False, where=None, reload=True, **kwargs): """ Convenience method to obtain settings interactively, if needed A UI will be used to ask for user input in interactive sessions. Questions to ask, and additional explanations can be passed directly as arguments, or retrieved from a list of pre-configured items. Additionally, this method allows for type conversion and storage of obtained settings. Both aspects can also be pre-configured. Parameters ---------- var : str Variable name including any section like `git config` expects them, e.g. 'core.editor' default : any type In interactive sessions and if `store` is True, this default value will be presented to the user for confirmation (or modification). In all other cases, this value will be silently assigned unless there is an existing configuration setting. dialog_type : {'question', 'yesno', None} Which dialog type to use in interactive sessions. If `None`, pre-configured UI options are used. store : bool Whether to store the obtained value (or default) %s `**kwargs` Additional arguments for the UI function call, such as a question `text`. """ # do local import, as this module is import prominently and the # could theroetically import all kind of weired things for type # conversion from datalad.interface.common_cfg import definitions as cfg_defs # fetch what we know about this variable cdef = cfg_defs.get(var, {}) # type conversion setup if valtype is None and 'type' in cdef: valtype = cdef['type'] if valtype is None: valtype = lambda x: x # any default? if default is None and 'default' in cdef: default = cdef['default'] _value = None if var in self: # nothing needs to be obtained, it is all here already _value = self[var] elif store is False and default is not None: # nothing will be stored, and we have a default -> no user confirmation # we cannot use logging, because we want to use the config to confiugre # the logging #lgr.debug('using default {} for config setting {}'.format(default, var)) _value = default if _value is not None: # we got everything we need and can exit early try: return valtype(_value) except Exception as e: raise ValueError( "value '{}' of existing configuration for '{}' cannot be " "converted to the desired type '{}' ({})".format( _value, var, valtype, exc_str(e))) # now we need to try to obtain something from the user from datalad.ui import ui # configure UI dialog_opts = kwargs if dialog_type is None: # no override # check for common knowledge on how to obtain a value if 'ui' in cdef: dialog_type = cdef['ui'][0] # pull standard dialog settings dialog_opts = cdef['ui'][1] # update with input dialog_opts.update(kwargs) if (not ui.is_interactive or dialog_type is None) and default is None: raise RuntimeError( "cannot obtain value for configuration item '{}', " "not preconfigured, no default, no UI available".format(var)) if not hasattr(ui, dialog_type): raise ValueError("UI '{}' does not support dialog type '{}'".format( ui, dialog_type)) # configure storage destination, if needed if store: if where is None and 'destination' in cdef: where = cdef['destination'] if where is None: raise ValueError( "request to store configuration item '{}', but no " "storage destination specified".format(var)) # obtain via UI dialog = getattr(ui, dialog_type) _value = dialog(default=default, **dialog_opts) if _value is None: # we got nothing if default is None: raise RuntimeError( "could not obtain value for configuration item '{}', " "not preconfigured, no default".format(var)) # XXX maybe we should return default here, even it was returned # from the UI -- if that is even possible # execute type conversion before storing to check that we got # something that looks like what we want try: value = valtype(_value) except Exception as e: raise ValueError( "cannot convert user input `{}` to desired type ({})".format( _value, exc_str(e))) # XXX we could consider "looping" until we have a value of proper # type in case of a user typo... if store: # store value as it was before any conversion, needs to be str # anyway # needs string conversion nevertheless, because default could come # in as something else self.add(var, '{}'.format(_value), where=where, reload=reload) return value
# # Compatibility with dict API # def __len__(self): return len(self._store) def __getitem__(self, key): return self._store.__getitem__(key) def __contains__(self, key): return self._store.__contains__(key)
[docs] def keys(self): """Returns list of configuration item names""" return self._store.keys()
# XXX should this be *args?
[docs] def get(self, key, default=None): """D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None.""" return self._store.get(key, default)
# # Compatibility with ConfigParser API #
[docs] def sections(self): """Returns a list of the sections available""" return list(set([cfg_section_regex.match(k).group(1) for k in self._store]))
[docs] def options(self, section): """Returns a list of options available in the specified section.""" opts = [] for k in self._store: sec, opt = cfg_sectionoption_regex.match(k).groups() if sec == section: opts.append(opt) return opts
[docs] def has_section(self, section): """Indicates whether a section is present in the configuration""" for k in self._store: if k.startswith(section): return True return False
[docs] def has_option(self, section, option): """If the given section exists, and contains the given option""" for k in self._store: sec, opt = cfg_sectionoption_regex.match(k).groups() if sec == section and opt == option: return True return False
[docs] def getint(self, section, option): """A convenience method which coerces the option value to an integer""" return int(self.get_value(section, option))
[docs] def getbool(self, section, option, default=None): """A convenience method which coerces the option value to a bool Values "on", "yes", "true" and any int!=0 are considered True Values which evaluate to bool False, "off", "no", "false" are considered False TypeError is raised for other values. """ val = self.get_value(section, option, default=default) return anything2bool(val)
[docs] def getfloat(self, section, option): """A convenience method which coerces the option value to a float""" return float(self.get_value(section, option))
# this is a hybrid of ConfigParser and dict API
[docs] def items(self, section=None): """Return a list of (name, value) pairs for each option Optionally limited to a given section. """ if section is None: return self._store.items() return [(k, v) for k, v in self._store.items() if cfg_section_regex.match(k).group(1) == section]
# # Compatibility with GitPython's ConfigParser #
[docs] def get_value(self, section, option, default=None): """Like `get()`, but with an optional default value If the default is not None, the given default value will be returned in case the option did not exist. This behavior imitates GitPython's config parser. """ try: return self['.'.join((section, option))] except KeyError as e: # this strange dance is needed because gitpython does it this way if default is not None: return default else: raise e
# # Modify configuration (proxy respective git-config call) # @_where_reload def _run(self, args, where=None, reload=False, **kwargs): """Centralized helper to run "git config" calls Parameters ---------- args : list Arguments to pass for git config %s **kwargs Keywords arguments for Runner's call """ if where: args = self._get_location_args(where) + args out = self._runner.run(['git', 'config'] + args, **kwargs) if reload: self.reload() return out def _get_location_args(self, where, args=None): if args is None: args = [] cfg_labels = ('dataset', 'local', 'global') if where not in cfg_labels: raise ValueError( "unknown configuration label '{}' (not in {})".format( where, cfg_labels)) if where == 'dataset': if not self._dataset_cfgfname: raise ValueError( 'ConfigManager cannot store to configuration to dataset, ' 'none specified') # create an empty config file if none exists, `git config` will # fail otherwise dscfg_dirname = opj(self._dataset_path, '.datalad') if not exists(dscfg_dirname): os.makedirs(dscfg_dirname) if not exists(self._dataset_cfgfname): open(self._dataset_cfgfname, 'w').close() args.extend(['--file', self._dataset_cfgfname]) elif where == 'global': args.append('--global') elif where == 'local': args.append('--local') return args
[docs] @_where_reload def add(self, var, value, where='dataset', reload=True): """Add a configuration variable and value Parameters ---------- var : str Variable name including any section like `git config` expects them, e.g. 'core.editor' value : str Variable value %s""" self._run(['--add', var, value], where=where, reload=reload, log_stderr=True)
[docs] @_where_reload def set(self, var, value, where='dataset', reload=True, force=False): """Set a variable to a value. In opposition to `add`, this replaces the value of `var` if there is one already. Parameters ---------- var : str Variable name including any section like `git config` expects them, e.g. 'core.editor' value : str Variable value force: bool if set, replaces all occurrences of `var` by a single one with the given `value`. Otherwise raise if multiple entries for `var` exist already %s""" from datalad.support.gitrepo import to_options self._run(to_options(replace_all=force) + [var, value], where=where, reload=reload, log_stderr=True)
[docs] @_where_reload def rename_section(self, old, new, where='dataset', reload=True): """Rename a configuration section Parameters ---------- old : str Name of the section to rename. new : str Name of the section to rename to. %s""" self._run(['--rename-section', old, new], where=where, reload=reload)
[docs] @_where_reload def remove_section(self, sec, where='dataset', reload=True): """Rename a configuration section Parameters ---------- sec : str Name of the section to remove. %s""" self._run(['--remove-section', sec], where=where, reload=reload)
[docs] @_where_reload def unset(self, var, where='dataset', reload=True): """Remove all occurrences of a variable Parameters ---------- var : str Name of the variable to remove %s""" # use unset all as it is simpler for now self._run(['--unset-all', var], where=where, reload=reload)