k3s/build/json-extractor.py

71 lines
2.0 KiB
Python
Executable File

#!/usr/bin/env python
# Copyright 2014 The Kubernetes Authors.
#
# 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.
# This is a very simple utility that reads a JSON document from stdin, parses it
# and returns the specified value. The value is described using a simple dot
# notation. If any errors are encountered along the way, an error is output and
# a failure value is returned.
from __future__ import print_function
import json
import sys
def PrintError(*err):
print(*err, file=sys.stderr)
def main():
try:
obj = json.load(sys.stdin)
except Exception, e:
PrintError("Error loading JSON: {0}".format(str(e)))
if len(sys.argv) == 1:
# if we don't have a query string, return success
return 0
elif len(sys.argv) > 2:
PrintError("Usage: {0} <json query>".format(sys.args[0]))
return 1
query_list = sys.argv[1].split('.')
for q in query_list:
if isinstance(obj, dict):
if q not in obj:
PrintError("Couldn't find '{0}' in dict".format(q))
return 1
obj = obj[q]
elif isinstance(obj, list):
try:
index = int(q)
except:
PrintError("Can't use '{0}' to index into array".format(q))
return 1
if index >= len(obj):
PrintError("Index ({0}) is greater than length of list ({1})".format(q, len(obj)))
return 1
obj = obj[index]
else:
PrintError("Trying to query non-queryable object: {0}".format(q))
return 1
if isinstance(obj, str):
print(obj)
else:
print(json.dumps(obj, indent=2))
if __name__ == "__main__":
sys.exit(main())