cli: Add clean and status subcommands

The 'cloud-init clean' command allows a user or script to clear cloud-init
artifacts from the system so that cloud-init sees the system as
unconfigured upon reboot. Optional parameters can be provided to remove
cloud-init logs and reboot after clean.

The 'cloud-init status' command allows the user or script to check whether
cloud-init has finished all configuration stages and whether errors
occurred. An optional --wait argument will poll on a 0.25 second interval
until cloud-init configuration is complete. The benefit here is scripts
can block on cloud-init completion before performing post-config tasks.

1 files changed, 157 insertions, 0 deletions

diff --git a/cloudinit/cmd/status.py b/cloudinit/cmd/status.py
new file mode 100644
index 00000000..3e5d0d07
--- /dev/null
+++ b/cloudinit/cmd/status.py
@@ -0,0 +1,157 @@
+# Copyright (C) 2017 Canonical Ltd.
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+
+"""Define 'status' utility and handler as part of cloud-init commandline."""
+
+import argparse
+import os
+import sys
+from time import gmtime, strftime, sleep
+
+from cloudinit.distros import uses_systemd
+from cloudinit.stages import Init
+from cloudinit.util import get_cmdline, load_file, load_json
+
+CLOUDINIT_DISABLED_FILE = '/etc/cloud/cloud-init.disabled'
+
+# customer visible status messages
+STATUS_ENABLED_NOT_RUN = 'not run'
+STATUS_RUNNING = 'running'
+STATUS_DONE = 'done'
+STATUS_ERROR = 'error'
+STATUS_DISABLED = 'disabled'
+
+
+def get_parser(parser=None):
+    """Build or extend an arg parser for status utility.
+
+    @param parser: Optional existing ArgumentParser instance representing the
+        status subcommand which will be extended to support the args of
+        this utility.
+
+    @returns: ArgumentParser with proper argument configuration.
+    """
+    if not parser:
+        parser = argparse.ArgumentParser(
+            prog='status',
+            description='Report run status of cloud init')
+    parser.add_argument(
+        '-l', '--long', action='store_true', default=False,
+        help=('Report long format of statuses including run stage name and'
+              ' error messages'))
+    parser.add_argument(
+        '-w', '--wait', action='store_true', default=False,
+        help='Block waiting on cloud-init to complete')
+    return parser
+
+
+def handle_status_args(name, args):
+    """Handle calls to 'cloud-init status' as a subcommand."""
+    # Read configured paths
+    init = Init(ds_deps=[])
+    init.read_cfg()
+
+    status, status_detail, time = _get_status_details(init.paths)
+    if args.wait:
+        while status in (STATUS_ENABLED_NOT_RUN, STATUS_RUNNING):
+            sys.stdout.write('.')
+            sys.stdout.flush()
+            status, status_detail, time = _get_status_details(init.paths)
+            sleep(0.25)
+        sys.stdout.write('\n')
+    if args.long:
+        print('status: {0}'.format(status))
+        if time:
+            print('time: {0}'.format(time))
+        print('detail:\n{0}'.format(status_detail))
+    else:
+        print('status: {0}'.format(status))
+    return 1 if status == STATUS_ERROR else 0
+
+
+def _is_cloudinit_disabled(disable_file, paths):
+    """Report whether cloud-init is disabled.
+
+    @param disable_file: The path to the cloud-init disable file.
+    @param paths: An initialized cloudinit.helpers.Paths object.
+    @returns: A tuple containing (bool, reason) about cloud-init's status and
+    why.
+    """
+    is_disabled = False
+    cmdline_parts = get_cmdline().split()
+    if not uses_systemd():
+        reason = 'Cloud-init enabled on sysvinit'
+    elif 'cloud-init=enabled' in cmdline_parts:
+        reason = 'Cloud-init enabled by kernel command line cloud-init=enabled'
+    elif os.path.exists(disable_file):
+        is_disabled = True
+        reason = 'Cloud-init disabled by {0}'.format(disable_file)
+    elif 'cloud-init=disabled' in cmdline_parts:
+        is_disabled = True
+        reason = 'Cloud-init disabled by kernel parameter cloud-init=disabled'
+    elif not os.path.exists(os.path.join(paths.run_dir, 'enabled')):
+        is_disabled = True
+        reason = 'Cloud-init disabled by cloud-init-generator'
+    return (is_disabled, reason)
+
+
+def _get_status_details(paths):
+    """Return a 3-tuple of status, status_details and time of last event.
+
+    @param paths: An initialized cloudinit.helpers.paths object.
+
+    Values are obtained from parsing paths.run_dir/status.json.
+    """
+
+    status = STATUS_ENABLED_NOT_RUN
+    status_detail = ''
+    status_v1 = {}
+
+    status_file = os.path.join(paths.run_dir, 'status.json')
+
+    (is_disabled, reason) = _is_cloudinit_disabled(
+        CLOUDINIT_DISABLED_FILE, paths)
+    if is_disabled:
+        status = STATUS_DISABLED
+        status_detail = reason
+    if os.path.exists(status_file):
+        status_v1 = load_json(load_file(status_file)).get('v1', {})
+    errors = []
+    latest_event = 0
+    for key, value in sorted(status_v1.items()):
+        if key == 'stage':
+            if value:
+                status_detail = 'Running in stage: {0}'.format(value)
+        elif key == 'datasource':
+            status_detail = value
+        elif isinstance(value, dict):
+            errors.extend(value.get('errors', []))
+            finished = value.get('finished') or 0
+            if finished == 0:
+                status = STATUS_RUNNING
+            event_time = max(value.get('start', 0), finished)
+            if event_time > latest_event:
+                latest_event = event_time
+    if errors:
+        status = STATUS_ERROR
+        status_detail = '\n'.join(errors)
+    elif status == STATUS_ENABLED_NOT_RUN and latest_event > 0:
+        status = STATUS_DONE
+    if latest_event:
+        time = strftime('%a, %d %b %Y %H:%M:%S %z', gmtime(latest_event))
+    else:
+        time = ''
+    return status, status_detail, time
+
+
+def main():
+    """Tool to report status of cloud-init."""
+    parser = get_parser()
+    sys.exit(handle_status_args('status', parser.parse_args()))
+
+
+if __name__ == '__main__':
+    main()
+
+# vi: ts=4 expandtab