Paste

by webjunkie on Cron, DB, Paste, Pyramid, Python, SQLAlchemy

Running Standalone SQLAlchemy Scripts in Pyramid

From time to time there comes the need to run automated scripts managed by either Python or Cron. In a recent project I had to run a standalone script that checks records on a database at certain hours. So here’s what I came up with. Most of the script is based on this post by Daniel Mayer.

from paste.deploy import appconfig
from sqlalchemy import engine_from_config
from sqlalchemy.orm.exc import NoResultFound, MultipleResultsFound
#here is where sqlalchemy objects are imported
from PRJ.models import DBSession as db,DBRecords
#import the session manager. This way commits will be handled automatically by the Zope Transaction Manager
import transaction
# Load Application Configuration and Return as Dictionary
conf = appconfig('config:' + 'development.ini',
        relative_to="/var/www/PRJ",
        name="main")
# Bind Engine Based on Config
engine = engine_from_config(conf, 'sqlalchemy.')
db.configure(bind=engine)
#Query the DB
data = db.query(DBRecords).one()
with transaction.manager:
  for record in data:
    #query or update DB
 
by webjunkie on Debian, Paste, Pylons, uWSGI

Paste Server init script in Debian

This past few months I’ve set up a few beta projects on a single Debian server, and now it has become a tedious task typing the command to start|restart|stop paste for each project everytime I push new code. So I decide it to create a init script to simplify things.
For this I’ve my virtual environment installed inside the project folder. Make sure to replace virtual-env whit the name of your virtual environment folder and ProjectName with the name of your project folder. Here’s how it looks:

#! /bin/sh
### BEGIN INIT INFO
# Provides:          paster
# Required-Start:    $all
# Required-Stop:     $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the paster server
# Description:       starts paster
### END INIT INFO
PROJECT=/var/www/ProjectName
PID_DIR=/opt/nginx/logs/ProjectName/
PID_FILE=/opt/nginx/logs/ProjectName/paster.pid
LOG_FILE=/opt/nginx/logs/ProjectName/paster.log
USER=root
GROUP=root
PROD_FILE=/var/www/ProjectName/production.ini
RET_VAL=0
cd $PROJECT
case "$1" in
start)
virtual-env/bin/paster  serve \
--daemon \
--pid-file=$PID_FILE \
--log-file=$LOG_FILE \
--user=$USER \
--group=$GROUP \
$PROD_FILE \
start
;;
stop)
virtual-env/bin/paster  serve \
--daemon \
--pid-file=$PID_FILE \
--log-file=$LOG_FILE \
--user=$USER \
--group=$GROUP \
$PROD_FILE \
stop
;;
restart)
virtual-env/bin/paster  serve \
--daemon \
--pid-file=$PID_FILE \
--log-file=$LOG_FILE \
--user=$USER \
--group=$GROUP \
$PROD_FILE \
restart
;;
*)
echo $"Usage: $0 {start|stop|restart}"
exit 1
esac

So now I can save this file as projectname-paster and move it to /etc/init.d/ and start it with:

sudo /etc/init.d/projectname-paster start | restart | stop