json_check.py

#

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.

#

Simple checker of all JSONs in the given directory (usually repository).

Usage:

json_check.py [-h] [-v] [-n] -d DIRECTORY

Optional arguments:

-h, --help       show this help message and exit
-v, --verbose    make it verbose
-n, --no-colors  disable color output
-d DIRECTORY--directory DIRECTORY
                 directory with JSON files to check

#

Link to generated documentation for this script:

https://redhatinsights.github.io/insights-results-aggregator/json_check.html

from pathlib import Path
from json import load
from sys import exit
from os import popen
from argparse import ArgumentParser

#

Try to execute tput to read control code for selected operation.

def read_control_code(operation):

#

    return popen("tput " + operation, "r").readline()

#

Check all JSON files found in current directory and all subdirectories.

def check_jsons(verbose, directory):

#

Reset counters with number of passes and number of failures.

    passes = 0
    failures = 0

#

Find all files in current directory and subdirectories with *.json extension. Files are found recursivelly.

    files = list(Path(directory).rglob("*.json"))

#

Iterate over all files found by previous command.

    for file in files:
        try:

#

If the file can be opened and loaded as JSON, everything is fine.

            with file.open() as fin:

#

Try to load and parse the content of JSON file.

                obj = load(fin)

#

At this point the JSON has been loaded and parsed correctly.

                if verbose is not None:
                    print("{} is valid".format(file))

                passes += 1
        except ValueError as e:

#

There are several reasons and possibilities why the file can not be read as JSON, so we just print the error message taken from exception object.

            print("{} is invalid".format(file))
            failures += 1
            print(e)

#

Just the counters needs to be returned because all other informations about problems have been displayed already.

    return passes, failures

#

Display report about number of passes and failures.

def display_report(passes, failures, nocolors):

#

First of all, we need to setup colors to be displayed on terminal. Colors are displayed by using terminal escape control codes. When color output are not enabled on command line, we can simply use empty strings in output instead of real color escape codes.

    red_background = green_background = magenta_background = no_color = ""

#

If colors are enabled by command line parameter, use control sequence returned by tput command.

    if not nocolors:
        red_background = read_control_code("setab 1")
        green_background = read_control_code("setab 2")
        magenta_background = read_control_code("setab 5")
        no_color = read_control_code("sgr0")

#

There are four possible outcomes of JSON check: 1. no JSON files has been found 2. all files are ok 3. none of JSON files can be read and parsed 4. some files can be read and parsed, some can not

    if failures == 0:

#

If there are no failures, then check if any JSON file has been found at all.

        if passes == 0:
            print("{}[WARN]{}: no JSON files detected".format(magenta_background, no_color))
        else:
            print("{}[OK]{}: all JSONs have proper format".format(green_background, no_color))
    else:
        print("{}[FAIL]{}: invalid JSON(s) detected".format(red_background, no_color))

#

Print just number of passes and failures at the end, as this information can be processed on CI.

    print("{} passes".format(passes))
    print("{} failures".format(failures))

#

Entry point to this tool.

def main():

#

First of all, we need to specify all command line flags that are recognized by this tool.

    parser = ArgumentParser()
    parser.add_argument("-v", "--verbose", dest="verbose", help="make it verbose",
                        action="store_true", default=None)
    parser.add_argument("-n", "--no-colors", dest="nocolors", help="disable color output",
                        action="store_true", default=None)
    parser.add_argument("-d", "--directory", dest="directory",
                        help="directory with JSON files to check",
                        action="store", default=".")

#

Now it is time to parse flags, check the actual content of command line and fill in the object stored in variable named args.

    args = parser.parse_args()

#

Check all JSON files, display problems, and get counters with number of passes and failures.

    passes, failures = check_jsons(args.verbose, args.directory)

#

Display detailed report and summary as well.

    display_report(passes, failures, args.nocolors)

#

If any error is found, return with exit code check to non-zero value.

    if failures > 0:
        exit(1)

#

If this script is started from command line, run the main function which represents entry point to the processing. Entry point to this tool.

if __name__ == "__main__":

#

    main()