aboutsummaryrefslogtreecommitdiffstats
path: root/contrail-controller/hooks/charmhelpers/fetch/snap.py
diff options
context:
space:
mode:
Diffstat (limited to 'contrail-controller/hooks/charmhelpers/fetch/snap.py')
-rw-r--r--contrail-controller/hooks/charmhelpers/fetch/snap.py122
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)