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Diffstat (limited to 'contrail-controller/hooks/charmhelpers/fetch/snap.py')
-rw-r--r-- | contrail-controller/hooks/charmhelpers/fetch/snap.py | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/contrail-controller/hooks/charmhelpers/fetch/snap.py b/contrail-controller/hooks/charmhelpers/fetch/snap.py new file mode 100644 index 0000000..23c707b --- /dev/null +++ b/contrail-controller/hooks/charmhelpers/fetch/snap.py @@ -0,0 +1,122 @@ +# Copyright 2014-2017 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +""" +Charm helpers snap for classic charms. + +If writing reactive charms, use the snap layer: +https://lists.ubuntu.com/archives/snapcraft/2016-September/001114.html +""" +import subprocess +from os import environ +from time import sleep +from charmhelpers.core.hookenv import log + +__author__ = 'Joseph Borg <joseph.borg@canonical.com>' + +SNAP_NO_LOCK = 1 # The return code for "couldn't acquire lock" in Snap (hopefully this will be improved). +SNAP_NO_LOCK_RETRY_DELAY = 10 # Wait X seconds between Snap lock checks. +SNAP_NO_LOCK_RETRY_COUNT = 30 # Retry to acquire the lock X times. + + +class CouldNotAcquireLockException(Exception): + pass + + +def _snap_exec(commands): + """ + Execute snap commands. + + :param commands: List commands + :return: Integer exit code + """ + assert type(commands) == list + + retry_count = 0 + return_code = None + + while return_code is None or return_code == SNAP_NO_LOCK: + try: + return_code = subprocess.check_call(['snap'] + commands, env=environ) + except subprocess.CalledProcessError as e: + retry_count += + 1 + if retry_count > SNAP_NO_LOCK_RETRY_COUNT: + raise CouldNotAcquireLockException('Could not aquire lock after %s attempts' % SNAP_NO_LOCK_RETRY_COUNT) + return_code = e.returncode + log('Snap failed to acquire lock, trying again in %s seconds.' % SNAP_NO_LOCK_RETRY_DELAY, level='WARN') + sleep(SNAP_NO_LOCK_RETRY_DELAY) + + return return_code + + +def snap_install(packages, *flags): + """ + Install a snap package. + + :param packages: String or List String package name + :param flags: List String flags to pass to install command + :return: Integer return code from snap + """ + if type(packages) is not list: + packages = [packages] + + flags = list(flags) + + message = 'Installing snap(s) "%s"' % ', '.join(packages) + if flags: + message += ' with option(s) "%s"' % ', '.join(flags) + + log(message, level='INFO') + return _snap_exec(['install'] + flags + packages) + + +def snap_remove(packages, *flags): + """ + Remove a snap package. + + :param packages: String or List String package name + :param flags: List String flags to pass to remove command + :return: Integer return code from snap + """ + if type(packages) is not list: + packages = [packages] + + flags = list(flags) + + message = 'Removing snap(s) "%s"' % ', '.join(packages) + if flags: + message += ' with options "%s"' % ', '.join(flags) + + log(message, level='INFO') + return _snap_exec(['remove'] + flags + packages) + + +def snap_refresh(packages, *flags): + """ + Refresh / Update snap package. + + :param packages: String or List String package name + :param flags: List String flags to pass to refresh command + :return: Integer return code from snap + """ + if type(packages) is not list: + packages = [packages] + + flags = list(flags) + + message = 'Refreshing snap(s) "%s"' % ', '.join(packages) + if flags: + message += ' with options "%s"' % ', '.join(flags) + + log(message, level='INFO') + return _snap_exec(['refresh'] + flags + packages) |