From 560eb051e127fe4b8b93104200fe55512a72038f Mon Sep 17 00:00:00 2001 From: Frederick Muriuki Muriithi Date: Mon, 24 Oct 2022 14:14:17 +0300 Subject: Add external process manager * wqflask/jobs/__init__.py: New jobs module * wqflask/jobs/jobs.py: New jobs module * wqflask/scripts/run_external.py: new external process manager. --- wqflask/scripts/run_external.py | 159 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 wqflask/scripts/run_external.py (limited to 'wqflask/scripts') diff --git a/wqflask/scripts/run_external.py b/wqflask/scripts/run_external.py new file mode 100644 index 00000000..3cefa033 --- /dev/null +++ b/wqflask/scripts/run_external.py @@ -0,0 +1,159 @@ +""" +Run jobs in external processes. +""" + +import os +import sys +import shlex +import argparse +import traceback +import subprocess +from uuid import UUID +from time import sleep +from datetime import datetime +from urllib.parse import urlparse +from tempfile import TemporaryDirectory + +# import psutil +from redis import Redis + +import jobs.jobs as jobs + +def print_help(args, parser): + print(parser.format_help()) + +def UUID4(val): + return UUID(val) + +def redis_connection(parsed_url): + return Redis.from_url( + f"redis://{parsed_url.netloc}{parsed_url.path}", decode_responses=True) + +def update_status(redis_conn: Redis, job_id: UUID, value: str): + "Update the job's status." + redis_conn.hset(jobs.job_namespace(job_id), key="status", value=value) + +def __update_stdout_stderr__( + redis_conn: Redis, job_id: UUID, bytes_read: bytes, stream: str): + job = jobs.job(redis_conn, job_id) + if job.is_nothing(): + raise jobs.NoSuchJob(job_id) + + job = job.maybe({}, lambda x: x) + redis_conn.hset( + jobs.job_namespace(job_id), key=stream, + value=(job.get(stream, "") + bytes_read.decode("utf-8"))) + +def set_stdout(redis_conn: Redis, job_id:UUID, bytes_read: bytes): + """Set the stdout value for the given job.""" + job = jobs.job(redis_conn, job_id) + if job.is_nothing(): + raise jobs.NoSuchJob(job_id) + + job = job.maybe({}, lambda x: x) + redis_conn.hset( + jobs.job_namespace(job_id), key="stdout", + value=bytes_read.decode("utf-8")) + +def update_stdout(redis_conn: Redis, job_id:UUID, bytes_read: bytes): + """Update the stdout value for the given job.""" + __update_stdout_stderr__(redis_conn, job_id, bytes_read, "stdout") + +def update_stderr(redis_conn: Redis, job_id:UUID, bytes_read: bytes): + """Update the stderr value for the given job.""" + __update_stdout_stderr__(redis_conn, job_id, bytes_read, "stderr") + +def set_meta(redis_conn: Redis, job_id: UUID, meta_key: str, meta_val: str): + job = jobs.job(redis_conn, job_id) + if job.is_nothing(): + raise jobs.NoSuchJob(job_id) + + redis_conn.hset(jobs.job_namespace(job_id), key=meta_key, value=meta_val) + +def run_job(redis_conn: Redis, job_id: UUID): + """Run the job in an external process.""" + print(f"THE ARGUMENTS TO RUN_JOB:\n\tConnection: {redis_conn}\n\tJob ID: {job_id}\n") + + the_job = jobs.job(redis_conn, job_id) + if the_job.is_nothing(): + raise jobs.NoSuchJob(job_id) + + with TemporaryDirectory() as tmpdir: + stdout_file = f"{tmpdir}/{job_id}.stdout" + stderr_file = f"{tmpdir}/{job_id}.stderr" + with open(stdout_file, "w+b") as outfl, open(stderr_file, "w+b") as errfl: + with subprocess.Popen( + jobs.command(the_job), stdout=outfl, + stderr=errfl) as process: + while process.poll() is None: + update_status(redis_conn, job_id, "running") + update_stdout(redis_conn, job_id, outfl.read1()) + sleep(1) + + update_status(redis_conn, job_id, "completed") + with open(stdout_file, "rb") as outfl, open(stderr_file, "rb") as errfl: + set_stdout(redis_conn, job_id, outfl.read()) + update_stderr(redis_conn, job_id, errfl.read()) + + os.remove(stdout_file) + os.remove(stderr_file) + + returncode = process.returncode + set_meta(redis_conn, job_id, "completion-status", + ("success" if returncode == 0 else "error")) + set_meta(redis_conn, job_id, "return-code", "error") + return process.returncode + +def run_job_parser(parent_parser): + parser = parent_parser.add_parser( + "run-job", + help="run job with given id") + parser.add_argument( + "job_id", type=UUID4, help="A string representing a UUID4 value.") + parser.set_defaults( + run=lambda conn, args, parser: run_job(conn, args.job_id)) + +def add_subparsers(parent_parser, *subparser_fns): + sub_parsers = parent_parser.add_subparsers( + title="subcommands", description="valid subcommands", required=True) + for parser_fn in subparser_fns: + parser_fn(sub_parsers) + pass + + return parent_parser + +def parse_cli_args(): + parser = add_subparsers(argparse.ArgumentParser( + description=sys.modules[__name__].__doc__.strip()), run_job_parser) + parser.add_argument( + "--redis-uri", required=True, + help=( + "URI to use to connect to job management db." + "The URI should be of the form " + "'://:@:/'"), + type=urlparse) + return parser, parser.parse_args() + +def launch_manager(): + parser, args = parse_cli_args() + with redis_connection(args.redis_uri) as conn: + try: + return args.run(conn, args, parser) + except Exception as nsj: + prev_msg = ( + conn.hget(f"{jobs.JOBS_NAMESPACE}:manager", key="stderr") or "") + if bool(prev_msg): + prev_msg = f"{prev_msg}\n" + + notfoundmsg = ( + f"{prev_msg}" + f"{datetime.now().isoformat()}: {type(nsj).__name__}: {traceback.format_exc()}") + conn.hset( + f"{jobs.JOBS_NAMESPACE}:manager", + key="stderr", + value=notfoundmsg) + +if __name__ == "__main__": + def run(): + sys.exit(launch_manager()) + run() -- cgit v1.2.3