Connect PG Simple
A simple, minimal PostgreSQL session store for Express/Connect
Installation
npm install connect-pg-simple
Once npm installed the module, you need to create the session table in your database. For that you can use the table.sql file provided with the module:
psql mydatabase < node_modules/connect-pg-simple/table.sql
Or simply play the file via a GUI, like the pgAdminIII queries tool.
Note that connect-pg-simple
requires PostgreSQL version 9.5 or above.
Usage
Examples are based on Express 4.
Simple example:
var session = require('express-session');
app.use(session({
store: new (require('connect-pg-simple')(session))(),
secret: process.env.FOO_COOKIE_SECRET,
resave: false,
cookie: { maxAge: 30 * 24 * 60 * 60 * 1000 } // 30 days
}));
Advanced example showing some custom options:
var pg = require('pg')
, session = require('express-session')
, pgSession = require('connect-pg-simple')(session);
var pgPool = new pg.Pool({
// Insert pool options here
});
app.use(session({
store: new pgSession({
pool : pgPool, // Connection pool
tableName : 'user_sessions' // Use another table-name than the default "session" one
}),
secret: process.env.FOO_COOKIE_SECRET,
resave: false,
cookie: { maxAge: 30 * 24 * 60 * 60 * 1000 } // 30 days
}));
Express 3 (and similar for Connect):
var express = require('express');
app.use(session({
store: new (require('connect-pg-simple')(express.session))(),
secret: process.env.FOO_COOKIE_SECRET,
cookie: { maxAge: 30 * 24 * 60 * 60 * 1000 } // 30 days
}));
Advanced options
- pool - Recommended. Connection pool object (compatible with pg.Pool) for the underlying database module. The conString option is ignored if this option is specified.
- pgPromise - Existing instance of
pg-promise
to be used for DB communications. The conString option is ignored if this option is specified. - conString - If you don't specify a pool object, use this option or
conObject
to specify a PostgreSQL connection string and this module will create a new pool for you. If the connection string is in theDATABASE_URL
environment variable (as you do by default on eg. Heroku) – then this module fallback to that if this option is not specified. - conObject - If you don't specify a pool object, use this option or
conString
to specify a PostgreSQL Pool connection object and this module will create a new pool for you. - ttl - the time to live for the session in the database – specified in seconds. Defaults to the cookie maxAge if the cookie has a maxAge defined and otherwise defaults to one day.
- schemaName - if your session table is in another Postgres schema than the default (it normally isn't), then you can specify that here.
- tableName - if your session table is named something else than
session
, then you can specify that here. - pruneSessionInterval - sets the delay in seconds at which expired sessions are pruned from the database. Default is
60
seconds. If set tofalse
no automatic pruning will happen. By default every delay is randomized between 50% and 150% of set value, resulting in an average delay equal to the set value, but spread out to even the load on the database. Automatic pruning will happenpruneSessionInterval
seconds after the last pruning (includes manual prunes). - pruneSessionRandomizedInterval – if set to
false
, then the exact value ofpruneSessionInterval
will be used in all delays. No randomization will happen. If multiple instances all start at once, disabling randomization can mean that multiple instances are all triggering pruning at once, causing unnecessary load on the database. Can also be set to a method, taking a numericdelay
parameter and returning a modified one, thus allowing a custom delay algorithm if wanted. - errorLog – the method used to log errors in those cases where an error can't be returned to a callback. Defaults to
console.error()
, but can be useful to override if one eg. uses Bunyan for logging.
Useful methods
- close() – if this module used its own database module to connect to Postgres, then this will shut that connection down to allow a graceful shutdown.
- pruneSessions([callback(err)]) – will prune old sessions. Only really needed to be called if pruneSessionInterval has been set to
false
– which can be useful if one wants improved control of the pruning.