PR#80: Use a safe NFS lock file mechanism for OpenShift deployment - mdapi

mdapi

#80 Use a safe NFS lock file mechanism for OpenShift deployment

Merged 5 years ago by pingou. Opened 5 years ago by cverna.

cverna/mdapi nfs_lock into master

Use a safe NFS lock file mechanism for OpenShift deployment

Clement Verna • 5 years ago

2e5b04d

Dockerfile

file modified

+1 -1

		`@@ -6,7 +6,7 @@`

		`EXPOSE 8080`

		`- RUN dnf -y install python3-aiohttp python3-werkzeug python3-requests python3-sqlalchemy python3-fedora-messaging`
		`+ RUN dnf -y install python3-aiohttp python3-werkzeug python3-requests python3-sqlalchemy python3-fedora-messaging python3-flufl-lock`

		`USER 1001`
		`ENV MDAPI_CONFIG=/etc/mdapi/mdapi.cfg`

mdapi-get_repo_md

file modified

+2 -2

		`@@ -52,9 +52,9 @@`
		`from sqlalchemy import text`
		`from fedora_messaging.api import Message, publish`
		`from fedora_messaging.exceptions import PublishReturned, ConnectionException`
		`+ from flufl.lock import Lock`

		`import mdapi.lib as mdapilib`
		`- import mdapi.file_lock as file_lock`

		`KOJI_REPO = 'https://kojipkgs.fedoraproject.org/repos/'`
		`PKGDB2_URL = 'https://admin.fedoraproject.org/pkgdb/'`
		`@@ -329,7 +329,7 @@`

		`def install_db(name, src, dest):`
		`print('%s Installing %s to %s.' % (name.ljust(padding), src, dest))`
		`- with file_lock.FileFlock(dest + '.lock'):`
		`+ with Lock(dest + '.lock'):`
		`shutil.move(src, dest)`

mdapi/__init__.py

file modified

+6 -5

		`@@ -34,9 +34,10 @@`
		`import werkzeug`
		`from aiohttp import web`
		`from multidict import MultiDict`
		`+ from flufl.lock import Lock`

		`import mdapi.lib as mdapilib`
		`- import mdapi.file_lock as file_lock`
		`+`


		`CONFIG = dict()`
		`@@ -114,7 +115,7 @@`

		`wrongdb = False`

		`- with file_lock.FileFlock(dbfile + '.lock'):`
		`+ with Lock(dbfile + '.lock'):`
		`session = yield from mdapilib.create_session(`
		`'sqlite:///%s' % dbfile)`
		`if name:`
		`@@ -166,7 +167,7 @@`
		`dbfile = '%s/mdapi-%s%s-primary.sqlite' % (`
		`CONFIG['DB_FOLDER'], branch, '-%s' % repotype if repotype else '')`

		`- with file_lock.FileFlock(dbfile + '.lock'):`
		`+ with Lock(dbfile + '.lock'):`
		`session = yield from mdapilib.create_session(`
		`'sqlite:///%s' % dbfile)`
		`# Fill in some extra info`
		`@@ -263,7 +264,7 @@`
		`if not os.path.exists(dbfile):`
		`raise web.HTTPBadRequest()`

		`- with file_lock.FileFlock(dbfile + '.lock'):`
		`+ with Lock(dbfile + '.lock'):`
		`session2 = yield from mdapilib.create_session(`
		`'sqlite:///%s' % dbfile)`
		`filelist = yield from mdapilib.get_files(session2, pkg.pkgId)`
		`@@ -296,7 +297,7 @@`
		`if not os.path.exists(dbfile):`
		`raise web.HTTPBadRequest()`

		`- with file_lock.FileFlock(dbfile + '.lock'):`
		`+ with Lock(dbfile + '.lock'):`
		`session2 = yield from mdapilib.create_session(`
		`'sqlite:///%s' % dbfile)`
		`changelogs = yield from mdapilib.get_changelog(session2, pkg.pkgId)`

mdapi/file_lock.py

file removed

-64

		`@@ -1,64 +0,0 @@`
		`- # -- coding: utf-8 --`
		`- #`
		`- # Copyright © derpston.`
		`- #`
		`- # Source: https://github.com/derpston/python-simpleflock/`
		`- #`
		`- # License: WTFPL`
		`- #`
		`-`
		`- '''`
		`- Simple file lock mechanism`
		`- '''`
		`-`
		`- import time`
		`- import os`
		`- import fcntl`
		`- import errno`
		`-`
		`-`
		`- class FileFlock:`
		`- """ Provides the simplest possible interface to flock-based file locking.`
		- Intended for use with the `with` syntax. It will create/truncate/delete
		`- the lock file as necessary.`
		`-`
		`- """`
		`-`
		`- def __init__(self, path, timeout=None, wait_for=0.1):`
		`- self._path = path`
		`- self._timeout = timeout`
		`- self._fd = None`
		`- self.wait_for = wait_for`
		`-`
		`- def __enter__(self):`
		`- self._fd = os.open(self._path, os.O_CREAT)`
		`- start_lock_search = time.time()`
		`- while True:`
		`- try:`
		`- fcntl.flock(self._fd, fcntl.LOCK_EX \| fcntl.LOCK_NB)`
		`- # Lock acquired!`
		`- return`
		`- except IOError as ex:`
		`- # Keep going if resource temporarily unavailable`
		`- if ex.errno != errno.EAGAIN:`
		`- raise`
		`- # Exceeded the user-specified timeout.`
		`- elif self._timeout is not None \`
		`- and time.time() > (start_lock_search + self._timeout):`
		`- raise`
		`-`
		`- # Let's not spin continuously`
		`- time.sleep(self.wait_for)`
		`-`
		`- def __exit__(self, *args):`
		`- fcntl.flock(self._fd, fcntl.LOCK_UN)`
		`- os.close(self._fd)`
		`- self._fd = None`
		`-`
		`- # Try to remove the lock file, but don't try too hard because it is`
		`- # unnecessary. This is mostly to help the user see whether a lock`
		`- # exists by examining the filesystem.`
		`- try:`
		`- os.unlink(self._path)`
		`- except:`
		`- pass`