+import os
+import sys
+import shutil
+import platform
+from glob import glob
+from subprocess import check_call
+
+from charms.layer.execd import execd_preinstall
+
+
+def bootstrap_charm_deps():
+ """
+ Set up the base charm dependencies so that the reactive system can run.
+ """
+ # execd must happen first, before any attempt to install packages or
+ # access the network, because sites use this hook to do bespoke
+ # configuration and install secrets so the rest of this bootstrap
+ # and the charm itself can actually succeed. This call does nothing
+ # unless the operator has created and populated $CHARM_DIR/exec.d.
+ execd_preinstall()
+ # ensure that $CHARM_DIR/bin is on the path, for helper scripts
+ os.environ['PATH'] += ':%s' % os.path.join(os.environ['CHARM_DIR'], 'bin')
+ venv = os.path.abspath('../.venv')
+ vbin = os.path.join(venv, 'bin')
+ vpip = os.path.join(vbin, 'pip')
+ vpy = os.path.join(vbin, 'python')
+ if os.path.exists('wheelhouse/.bootstrapped'):
+ from charms import layer
+ cfg = layer.options('basic')
+ if cfg.get('use_venv') and '.venv' not in sys.executable:
+ # activate the venv
+ os.environ['PATH'] = ':'.join([vbin, os.environ['PATH']])
+ reload_interpreter(vpy)
+ return
+ # bootstrap wheelhouse
+ if os.path.exists('wheelhouse'):
+ with open('/root/.pydistutils.cfg', 'w') as fp:
+ # make sure that easy_install also only uses the wheelhouse
+ # (see https://github.com/pypa/pip/issues/410)
+ charm_dir = os.environ['CHARM_DIR']
+ fp.writelines([
+ "[easy_install]\n",
+ "allow_hosts = ''\n",
+ "find_links = file://{}/wheelhouse/\n".format(charm_dir),
+ ])
+ apt_install(['python3-pip', 'python3-setuptools', 'python3-yaml'])
+ from charms import layer
+ cfg = layer.options('basic')
+ # include packages defined in layer.yaml
+ apt_install(cfg.get('packages', []))
+ # if we're using a venv, set it up
+ if cfg.get('use_venv'):
+ if not os.path.exists(venv):
+ distname, version, series = platform.linux_distribution()
+ if series in ('precise', 'trusty'):
+ apt_install(['python-virtualenv'])
+ else:
+ apt_install(['virtualenv'])
+ cmd = ['virtualenv', '-ppython3', '--never-download', venv]
+ if cfg.get('include_system_packages'):
+ cmd.append('--system-site-packages')
+ check_call(cmd)
+ os.environ['PATH'] = ':'.join([vbin, os.environ['PATH']])
+ pip = vpip
+ else:
+ pip = 'pip3'
+ # save a copy of system pip to prevent `pip3 install -U pip`
+ # from changing it
+ if os.path.exists('/usr/bin/pip'):
+ shutil.copy2('/usr/bin/pip', '/usr/bin/pip.save')
+ # need newer pip, to fix spurious Double Requirement error:
+ # https://github.com/pypa/pip/issues/56
+ check_call([pip, 'install', '-U', '--no-index', '-f', 'wheelhouse',
+ 'pip'])
+ # install the rest of the wheelhouse deps
+ check_call([pip, 'install', '-U', '--no-index', '-f', 'wheelhouse'] +
+ glob('wheelhouse/*'))
+ if not cfg.get('use_venv'):
+ # restore system pip to prevent `pip3 install -U pip`
+ # from changing it
+ if os.path.exists('/usr/bin/pip.save'):
+ shutil.copy2('/usr/bin/pip.save', '/usr/bin/pip')
+ os.remove('/usr/bin/pip.save')
+ os.remove('/root/.pydistutils.cfg')
+ # flag us as having already bootstrapped so we don't do it again
+ open('wheelhouse/.bootstrapped', 'w').close()
+ # Ensure that the newly bootstrapped libs are available.
+ # Note: this only seems to be an issue with namespace packages.
+ # Non-namespace-package libs (e.g., charmhelpers) are available
+ # without having to reload the interpreter. :/
+ reload_interpreter(vpy if cfg.get('use_venv') else sys.argv[0])
+
+
+def reload_interpreter(python):
+ """
+ Reload the python interpreter to ensure that all deps are available.
+
+ Newly installed modules in namespace packages sometimes seemt to
+ not be picked up by Python 3.
+ """
+ os.execle(python, python, sys.argv[0], os.environ)
+
+
+def apt_install(packages):
+ """
+ Install apt packages.
+
+ This ensures a consistent set of options that are often missed but
+ should really be set.
+ """
+ if isinstance(packages, (str, bytes)):
+ packages = [packages]
+
+ env = os.environ.copy()
+
+ if 'DEBIAN_FRONTEND' not in env:
+ env['DEBIAN_FRONTEND'] = 'noninteractive'
+
+ cmd = ['apt-get',
+ '--option=Dpkg::Options::=--force-confold',
+ '--assume-yes',
+ 'install']
+ check_call(cmd + packages, env=env)
+
+
+def init_config_states():
+ import yaml
+ from charmhelpers.core import hookenv
+ from charms.reactive import set_state
+ from charms.reactive import toggle_state
+ config = hookenv.config()
+ config_defaults = {}
+ config_defs = {}
+ config_yaml = os.path.join(hookenv.charm_dir(), 'config.yaml')
+ if os.path.exists(config_yaml):
+ with open(config_yaml) as fp:
+ config_defs = yaml.load(fp).get('options', {})
+ config_defaults = {key: value.get('default')
+ for key, value in config_defs.items()}
+ for opt in config_defs.keys():
+ if config.changed(opt):
+ set_state('config.changed')
+ set_state('config.changed.{}'.format(opt))
+ toggle_state('config.set.{}'.format(opt), config.get(opt))
+ toggle_state('config.default.{}'.format(opt),
+ config.get(opt) == config_defaults[opt])
+ hookenv.atexit(clear_config_states)
+
+
+def clear_config_states():
+ from charmhelpers.core import hookenv, unitdata
+ from charms.reactive import remove_state
+ config = hookenv.config()
+ remove_state('config.changed')
+ for opt in config.keys():
+ remove_state('config.changed.{}'.format(opt))
+ remove_state('config.set.{}'.format(opt))
+ remove_state('config.default.{}'.format(opt))
+ unitdata.kv().flush()