fix: fixed `should_reload` behaviour, close PostgreSQL connections, block until `PostgresqlWatcher` is ready, refactorings (#29) * chore: updated dev requirements * chore: format code with black * chore: updated .gitignore * fix: type hint, multiprocessing.Pipe is a Callable and not a type * fix: make Watcher.should_reload return value consistent * fix: Handle Connection and Process objects consistenly and close them before creating new ones * feat: Customize the postgres channel name * chore: Some code reorg - Make PostgresqlWatcher.create_subscription_process a private method - Rename casbin_subscription to _casbin_channel_subscription * docs: added doc string for PostgresqlWatcher.update * refactor: PostgresqlWatcher.set_update_callback * refactor!: Rename 'start_process' flag to 'start_listening' * docs: Added doc string to PostgresqlWatcher.__init__ * fix: Added proper destructor for PostgresqlWatcher * chore: fix type hints and proper handling of the channel_name argument and its default value * test: fix tests decrease select timeout to one second in child Process remove infinite timout in PostgresqlWatcher.should_reload create a new watcher instance for every test case * feat: Setup logging module for unit tests * fix: typo * feat: channel subscription with proper resource cleanup Moved channel subscription function to separate file and added context manager for the connection, that handles SIGINT, SIGTERM for proper resource cleanup * chore: removed unnecessary tests * feat: Wait for Process to be ready to receive messages from PostgreSQL * test: multiple instances of the watcher * test: make sure every test case uses its own channel * test: no update * refactor: moved code into with block * feat: automaticall call the update handler if it is provided * refactor: sorted imports * docs: updated README * refactor: improved readibility * refactor: resolve a potential infinite loop with a custom Exception * refactor: make timeout configurable by the user * fix: docs * fix: ensure type hint compatibility with Python 3.9 * feat: make sure multiple calls of update() get resolved by one call of should_reload() thanks to @pradeepranwa1

tree: 0e3130331394c0ddfd36cb94fd65a76a49308c21

README.md

postgresql-watcher

Casbin watcher based on PostgreSQL for monitoring updates to casbin policies.

Installation

pip install casbin-postgresql-watcher

Basic Usage Example

from flask_authz import CasbinEnforcer
from postgresql_watcher import PostgresqlWatcher
from flask import Flask
from casbin.persist.adapters import FileAdapter

casbin_enforcer = CasbinEnforcer(app, adapter)
watcher = PostgresqlWatcher(host=HOST, port=PORT, user=USER, password=PASSWORD, dbname=DBNAME)
watcher.set_update_callback(casbin_enforcer.load_policy)
casbin_enforcer.set_watcher(watcher)

# Call should_reload before every call of enforce to make sure
# the policy is update to date
watcher.should_reload()
if casbin_enforcer.enforce("alice", "data1", "read"):
    # permit alice to read data1
    pass
else:
    # deny the request, show an error
    pass

alternatively, if you need more control

from flask_authz import CasbinEnforcer
from postgresql_watcher import PostgresqlWatcher
from flask import Flask
from casbin.persist.adapters import FileAdapter

casbin_enforcer = CasbinEnforcer(app, adapter)
watcher = PostgresqlWatcher(host=HOST, port=PORT, user=USER, password=PASSWORD, dbname=DBNAME)
casbin_enforcer.set_watcher(watcher)

# Call should_reload before every call of enforce to make sure
# the policy is update to date
if watcher.should_reload():
    casbin_enforcer.load_policy()

if casbin_enforcer.enforce("alice", "data1", "read"):
    # permit alice to read data1
    pass
else:
    # deny the request, show an error
    pass

Basic Usage Example With SSL Enabled

See PostgresQL documentation for full details of SSL parameters.

...
watcher = PostgresqlWatcher(host=HOST, port=PORT, user=USER, password=PASSWORD, dbname=DBNAME, sslmode="verify_full", sslcert=SSLCERT, sslrootcert=SSLROOTCERT, sslkey=SSLKEY)
...