def update_metaconfig(metaconfig_name, *args, **kwargs):
zk_value, version = _kazoo_client(ZK_HOSTS).get(
METACONFIG_ZK_PATH_FORMAT.format(metaconfig_name))
s3_key = METACONFIG_S3_KEY_FORMAT.format(metaconfig_name)
s3_path = zk_util.construct_s3_path(s3_key, zk_value)
try:
metaconfig_data = s3config.S3Config(AWS_KEY_FILE, S3_BUCKET, s3_endpoint=S3_ENDPOINT).get_config_string(s3_path)
except ValueError as ve:
log.error("Abort downloading from s3 key %s due to ValueError: %s" % (s3_path, ve))
return
except Exception as e:
log.error("Abort downloading from s3 key %s due to unexpected s3 exception: %s" %
(s3_path, e))
return
metaconfig_list = json.loads(metaconfig_data)
for metaconfig in metaconfig_list:
_place_watch_from_metaconfig(metaconfig)
def update_metaconfig(metaconfig_name, *args, **kwargs):
zk_value, version = _kazoo_client(ZK_HOSTS).get(
METACONFIG_ZK_PATH_FORMAT.format(metaconfig_name))
s3_key = METACONFIG_S3_KEY_FORMAT.format(metaconfig_name)
s3_path = zk_util.construct_s3_path(s3_key, zk_value)
try:
metaconfig_data = s3config.S3Config(AWS_KEY_FILE, S3_BUCKET, s3_endpoint=S3_ENDPOINT).get_config_string(s3_path)
except ValueError as ve:
log.error("Abort downloading from s3 key %s due to ValueError: %s" % (s3_path, ve))
return
except Exception as e:
log.error("Abort downloading from s3 key %s due to unexpected s3 exception: %s" %
(s3_path, e))
return
metaconfig_list = json.loads(metaconfig_data)
for metaconfig in metaconfig_list:
_place_watch_from_metaconfig(metaconfig)
def main():
global args
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
"-f",
"--file",
dest="file",
metavar="FILENAME",
required=True,
help="The target file name for storing the downloaded data.",
)
parser.add_argument("-p",
"--path",
dest="path",
metavar="PATH",
help="The zookeeper path to download data from")
parser.add_argument("-m",
"--mode",
dest="mode",
metavar="MODE",
required=True,
help="The download mode [config | serverset]")
parser.add_argument(
"-s",
"--show",
dest="show",
action='store_true',
help="Flag to indicate whether to show the value in zookeeper only, "
"no change is really made when it is set.")
parser.add_argument(
"--allow-same-content",
dest="allow_same_content",
action='store_true',
help="Flag to indicate whether the script thinks downloading the same "
"content is OK, no setting this flag will make the script exit "
"with non-zero code when the content in zookeeper is the same as "
"the target file.")
parser.add_argument(
"-r",
"--serverset-rejection-ratio",
dest="rejection_ratio",
metavar="RATIO",
default=DEFAULT_SERVERSET_REJECTION_RATIO,
type=float,
help="The ratio to reject a new serverset, if the count of servers "
"in the new serverset is smaller than the multiplication of the "
"count of servers in the existing target file and the ratio, the "
"new serverset will be rejected and not written to the target"
"file, default is %.2f." % DEFAULT_SERVERSET_REJECTION_RATIO)
parser.add_argument(
"--serverset-minimum-size",
dest="serverset_minimum_size",
metavar="MINSIZE",
default=DEFAULT_SERVERSET_MINIMUM_SIZE,
type=int,
help="The minimum size of a serverset. If the serverset's size ever"
"falls below this min size, zk_update_monitor will reject the update"
"and will not write to the target file. Default is %d." %
DEFAULT_SERVERSET_MINIMUM_SIZE)
parser.add_argument(
"-v",
"--value",
dest="value",
metavar="VALUE",
help="The value in zookeeper, once this is provided, the script will "
"not try to get data from zookeeper, instead it will use this "
"provided value to write to the file. For config mode, the value "
"is the same as the data in zookeeper, for serverset mode, the "
"value is a list of hosts separated by ','")
parser.add_argument("--from-s3",
dest="s3_key",
metavar="S3_KEY",
help="The S3 key to download the data from")
parser.add_argument("--report-metadata",
dest="report_metadata",
default=False,
action='store_true',
help="If enabled, the downloader script "
"will report metadata of serverset"
"or config back to the caller (zk_download_data.py)")
parser.add_argument("-l",
"--from-value-file",
dest="from_value_file",
help="To get the actual value from a file")
parser.add_argument("-o",
"--port",
dest="port",
metavar="PORT",
help="The port the flask app in ZUM is running on")
######## REQUIRED #########
# ZK / S3 Configurations. #
###########################
parser.add_argument(
"-z",
"--zk-hosts-file-path",
dest="zk_hosts_file",
metavar="ZKHOSTS",
required=True,
help="The path of file which have a list of Zookeeper endpoints "
"(host:port) which keeps the metaconfig as well as "
"the config/serversets")
parser.add_argument(
"-a",
"--aws-key-file",
dest="aws_key_file",
metavar="AWSKEY",
help="The path of the file storing AWS access and secret keys",
)
parser.add_argument("-b",
"--s3-bucket",
dest="s3_bucket",
metavar="BUCKET",
help="The S3 bucket storing metaconfigs / configs")
parser.add_argument("-e",
"--aws-s3-endpoint",
dest="s3_endpoint",
metavar="ENDPOINT",
default="s3.amazonaws.com",
help="The S3 endpoint storing metaconfig / configs")
args = parser.parse_args()
mode = args.mode.upper()
initialize_zookeeper_aws_s3_configs(args)
initialize_zk_update_monitor_endpoints(args.port)
version = None
notification_timestamp = time.time()
# this is used to calculate MD5 which is consistent with the santinized
# value in zk_update_monitor
santinized_zk_data = None
if mode == 'CONFIG' and args.s3_key:
if not AWS_KEY_FILE or not S3_BUCKET or not S3_ENDPOINT:
log.error(
"No AWS key file or S3 Config is provided for accessing S3.")
exit(_NO_AWS_KEY_FILE)
log.info("Downloading from s3 key %s in bucket %s" %
(args.s3_key, S3_BUCKET))
# We use the s3_key (which is actually a prefix) concatenated with the value from zk node to
# form the s3 path. Therefore, each time we update new data to s3, we create a new S3
# key(can be located from the zk_node value), so as to make use of the "almost"
# read-after-create guarantee from the s3 "special" url.
zk_value = args.value
if zk_value:
log.debug("Use provided value %s" % zk_value)
else:
zk_value, version = \
get_data_from_zk(args.path, mode)
s3_path = zk_util.construct_s3_path(args.s3_key, zk_value)
# Download data from the s3 path.
try:
zk_data = s3config.S3Config(
AWS_KEY_FILE, S3_BUCKET,
s3_endpoint=S3_ENDPOINT).get_config_string(s3_path)
except ValueError as ve:
# If the s3 key specified by the zk_node does not exist, this is probably due to s3
# read-after-write inconsistency. Abort updating the local file.
log.error(
"Abort downloading from s3 key %s due to ValueError: %s" %
(s3_path, str(ve)))
exit(_S3_VALUE_ERROR_CODE)
except Exception as e:
log.error(
"Abort downloading from s3 key %s due to unexpected s3 exception: %s"
% (s3_path, str(e)))
exit(_S3_ERROR_CODE)
else:
if args.value:
log.debug("Use provided value %s" % args.value)
if mode == 'SERVERSET':
# remove duplicates in the server set value
endpoints_set = set(args.value.split(','))
verify_and_correct_endpoints_set(endpoints_set, args.file)
zk_data = '\n'.join(endpoints_set)
else:
zk_data = args.value
elif args.from_value_file:
from_value_file = args.from_value_file
log.debug("Use provided value in %s" % args.from_value_file)
try:
with open(from_value_file, 'r') as f:
# verify the file content is good.
value = f.readline().rstrip('\n')
md5digest = f.readline()
calculated_md5digest = zk_util.get_md5_digest(value)
if calculated_md5digest != md5digest:
log.error("Temp file %s content does not match md5" %
from_value_file)
f.close()
exit(_BROKEN_VALUE_FILE)
if mode == 'SERVERSET':
endpoints_set = set(value.split(','))
verify_and_correct_endpoints_set(endpoints_set, args.file)
zk_data = '\n'.join(endpoints_set)
else:
zk_data = value
except:
log.error("Error reading from temp file %s" % from_value_file)
exit(_BROKEN_VALUE_FILE)
else:
zk_data, version = \
get_data_from_zk(args.path, mode)
if zk_data is None:
log.error("Failed to get data from zookeeper.")
exit(_FAILED_TO_GET_DATA_FROM_ZK_CODE)
if args.show:
print(zk_data)
return
log.debug("Target file = %s" % (args.file))
try:
with open(args.file, "r") as file:
existing_content = file.read()
except IOError:
existing_content = None
if args.report_metadata:
if mode == 'SERVERSET':
serverset_list = zk_data.split('\n')
serverset_list.sort()
santinized_zk_data = string.join(serverset_list, ',')
# Get the file modification time
if args.file and os.path.exists(args.file):
modification_timestamp = os.path.getmtime(args.file)
else:
modification_timestamp = 0
report_metadata(mode, santinized_zk_data, args.path, version,
notification_timestamp, modification_timestamp)
if _same_content(existing_content, zk_data, mode):
log.warn("The data in zookeeper is the same as the target file %s, "
"ignore." % args.file)
if not args.allow_same_content:
# Needs to exit with the special return code so the daemon can
# ignore it.
exit(_SAME_CONTENT_CODE)
else:
exit(0)
found_stale_content = False
if os.environ.get('__ZK_UPDATE_MONITOR_REFRESH__', False):
found_stale_content = \
_check_stale_file_content(existing_content, args.file,
zk_data, mode)
log.info("Generating file %s with the data from zookeeper..." %
(args.file))
tmp_dir = tempfile.gettempprefix()
tmp_filename = os.path.join('/', tmp_dir, args.file.replace("/", "_"))
try:
with open(tmp_filename, 'w') as f:
f.write(zk_data)
except:
log.exception("Failed to generate file %s from config in zookeeper. "
"Data to write: %s" % (tmp_filename, zk_data))
exit(_UNHANDLED_EXCPETION)
shutil.copy2(tmp_filename, args.file)
log.info("File is generated.")
# Report the file modification time.
report_file_modification(mode, args.path, time.time())
if found_stale_content:
exit(_STALE_LOCAL_FILE_CODE)
def main():
global args
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument(
"-f", "--file", dest="file", metavar="FILENAME", required=True,
help="The target file name for storing the downloaded data.",)
parser.add_argument(
"-p", "--path", dest="path", metavar="PATH",
help="The zookeeper path to download data from")
parser.add_argument(
"-m", "--mode", dest="mode", metavar="MODE", required=True,
help="The download mode [config | serverset]")
parser.add_argument(
"-s", "--show", dest="show", action='store_true',
help="Flag to indicate whether to show the value in zookeeper only, "
"no change is really made when it is set.")
parser.add_argument(
"--allow-same-content", dest="allow_same_content",
action='store_true',
help="Flag to indicate whether the script thinks downloading the same "
"content is OK, no setting this flag will make the script exit "
"with non-zero code when the content in zookeeper is the same as "
"the target file.")
parser.add_argument(
"-r", "--serverset-rejection-ratio", dest="rejection_ratio",
metavar="RATIO", default=DEFAULT_SERVERSET_REJECTION_RATIO, type=float,
help="The ratio to reject a new serverset, if the count of servers "
"in the new serverset is smaller than the multiplication of the "
"count of servers in the existing target file and the ratio, the "
"new serverset will be rejected and not written to the target"
"file, default is %.2f." % DEFAULT_SERVERSET_REJECTION_RATIO)
parser.add_argument(
"--serverset-minimum-size", dest="serverset_minimum_size",
metavar="MINSIZE", default=DEFAULT_SERVERSET_MINIMUM_SIZE, type=int,
help="The minimum size of a serverset. If the serverset's size ever"
"falls below this min size, zk_update_monitor will reject the update"
"and will not write to the target file. Default is %d."
% DEFAULT_SERVERSET_MINIMUM_SIZE)
parser.add_argument(
"-v", "--value", dest="value", metavar="VALUE",
help="The value in zookeeper, once this is provided, the script will "
"not try to get data from zookeeper, instead it will use this "
"provided value to write to the file. For config mode, the value "
"is the same as the data in zookeeper, for serverset mode, the "
"value is a list of hosts separated by ','")
parser.add_argument(
"--from-s3", dest="s3_key", metavar="S3_KEY",
help="The S3 key to download the data from")
parser.add_argument(
"--report-metadata", dest="report_metadata",
default=False, action='store_true',
help="If enabled, the downloader script "
"will report metadata of serverset"
"or config back to the caller (zk_download_data.py)"
)
parser.add_argument(
"-l", "--from-value-file", dest="from_value_file",
help="To get the actual value from a file"
)
parser.add_argument(
"-o", "--port", dest="port", metavar="PORT",
help="The port the flask app in ZUM is running on"
)
######## REQUIRED #########
# ZK / S3 Configurations. #
###########################
parser.add_argument(
"-z", "--zk-hosts-file-path", dest="zk_hosts_file", metavar="ZKHOSTS",
required=True,
help="The path of file which have a list of Zookeeper endpoints "
"(host:port) which keeps the metaconfig as well as "
"the config/serversets"
)
parser.add_argument(
"-a", "--aws-key-file", dest="aws_key_file", metavar="AWSKEY",
help="The path of the file storing AWS access and secret keys",
)
parser.add_argument(
"-b", "--s3-bucket", dest="s3_bucket", metavar="BUCKET",
help="The S3 bucket storing metaconfigs / configs"
)
parser.add_argument(
"-e", "--aws-s3-endpoint", dest="s3_endpoint", metavar="ENDPOINT",
default="s3.amazonaws.com",
help="The S3 endpoint storing metaconfig / configs"
)
args = parser.parse_args()
mode = args.mode.upper()
initialize_zookeeper_aws_s3_configs(args)
initialize_zk_update_monitor_endpoints(args.port)
version = None
notification_timestamp = time.time()
# this is used to calculate MD5 which is consistent with the santinized
# value in zk_update_monitor
santinized_zk_data = None
if mode == 'CONFIG' and args.s3_key:
if not AWS_KEY_FILE or not S3_BUCKET or not S3_ENDPOINT:
log.error("No AWS key file or S3 Config is provided for accessing S3.")
exit(_NO_AWS_KEY_FILE)
log.info("Downloading from s3 key %s in bucket %s"
% (args.s3_key, S3_BUCKET))
# We use the s3_key (which is actually a prefix) concatenated with the value from zk node to
# form the s3 path. Therefore, each time we update new data to s3, we create a new S3
# key(can be located from the zk_node value), so as to make use of the "almost"
# read-after-create guarantee from the s3 "special" url.
zk_value = args.value
if zk_value:
log.debug("Use provided value %s" % zk_value)
else:
zk_value, version = \
get_data_from_zk(args.path, mode)
s3_path = zk_util.construct_s3_path(args.s3_key, zk_value)
# Download data from the s3 path.
try:
zk_data = s3config.S3Config(AWS_KEY_FILE, S3_BUCKET, s3_endpoint=S3_ENDPOINT).get_config_string(s3_path)
except ValueError as ve:
# If the s3 key specified by the zk_node does not exist, this is probably due to s3
# read-after-write inconsistency. Abort updating the local file.
log.error("Abort downloading from s3 key %s due to ValueError: %s" % (s3_path, str(ve)))
exit(_S3_VALUE_ERROR_CODE)
except Exception as e:
log.error("Abort downloading from s3 key %s due to unexpected s3 exception: %s" %
(s3_path, str(e)))
exit(_S3_ERROR_CODE)
else:
if args.value:
log.debug("Use provided value %s" % args.value)
if mode == 'SERVERSET':
# remove duplicates in the server set value
endpoints_set = set(args.value.split(','))
verify_and_correct_endpoints_set(endpoints_set, args.file)
zk_data = '\n'.join(endpoints_set)
else:
zk_data = args.value
elif args.from_value_file:
from_value_file = args.from_value_file
log.debug("Use provided value in %s" % args.from_value_file)
try:
with open(from_value_file, 'r') as f:
# verify the file content is good.
value = f.readline().rstrip('\n')
md5digest = f.readline()
calculated_md5digest = zk_util.get_md5_digest(value)
if calculated_md5digest != md5digest:
log.error("Temp file %s content does not match md5" % from_value_file)
f.close()
exit(_BROKEN_VALUE_FILE)
if mode == 'SERVERSET':
endpoints_set = set(value.split(','))
verify_and_correct_endpoints_set(endpoints_set, args.file)
zk_data = '\n'.join(endpoints_set)
else:
zk_data = value
except:
log.error("Error reading from temp file %s" % from_value_file)
exit(_BROKEN_VALUE_FILE)
else:
zk_data, version = \
get_data_from_zk(args.path, mode)
if zk_data is None:
log.error("Failed to get data from zookeeper.")
exit(_FAILED_TO_GET_DATA_FROM_ZK_CODE)
if args.show:
print(zk_data)
return
log.debug("Target file = %s" % (args.file))
try:
with open(args.file, "r") as file:
existing_content = file.read()
except IOError:
existing_content = None
if args.report_metadata:
if mode == 'SERVERSET':
serverset_list = zk_data.split('\n')
serverset_list.sort()
santinized_zk_data = string.join(serverset_list, ',')
# Get the file modification time
if args.file and os.path.exists(args.file):
modification_timestamp = os.path.getmtime(args.file)
else:
modification_timestamp = 0
report_metadata(mode, santinized_zk_data, args.path, version,
notification_timestamp, modification_timestamp)
if _same_content(existing_content, zk_data, mode):
log.warn("The data in zookeeper is the same as the target file %s, "
"ignore." % args.file)
if not args.allow_same_content:
# Needs to exit with the special return code so the daemon can
# ignore it.
exit(_SAME_CONTENT_CODE)
else:
exit(0)
found_stale_content = False
if os.environ.get('__ZK_UPDATE_MONITOR_REFRESH__', False):
found_stale_content = \
_check_stale_file_content(existing_content, args.file,
zk_data, mode)
log.info("Generating file %s with the data from zookeeper..."
% (args.file))
tmp_dir = tempfile.gettempprefix()
tmp_filename = os.path.join('/', tmp_dir, args.file.replace("/", "_"))
try:
with open(tmp_filename, 'w') as f:
f.write(zk_data)
except:
log.exception("Failed to generate file %s from config in zookeeper. "
"Data to write: %s" % (tmp_filename, zk_data))
exit(_UNHANDLED_EXCPETION)
shutil.copy2(tmp_filename, args.file)
log.info("File is generated.")
# Report the file modification time.
report_file_modification(mode, args.path, time.time())
if found_stale_content:
exit(_STALE_LOCAL_FILE_CODE)
