Complete configuration¶

Configuration options¶

You can look current settings with the following command:

pythonnest-manage config

Here is the complete list of settings:

[database]
engine = django.db.backends.postgresql_psycopg2
# SQL database engine, can be 'django.db.backends.[postgresql_psycopg2|mysql|sqlite3|oracle]'.
host = localhost
# Empty for localhost through domain sockets or "127.0.0.1" for localhost + TCP
name = pythonnest
# Name of your database, or path to database file if using sqlite3.
password = 5trongp4ssw0rd
# Database password (not used with sqlite3)
port = 5432
# Database port, leave it empty for default (not used with sqlite3)
user = pythonnest
# Database user (not used with sqlite3)
[global]
admin_email = admin@pythonnest.example.org
# error logs are sent to this e-mail address
bind_address = localhost:8130
# The socket (IP address:port) to bind to.
data_path = /var/pythonnest
# Base path for all data
debug = False
# A boolean that turns on/off debug mode.
extra_apps =
# List of extra installed Django apps (separated by commas).
language_code = fr-FR
# A string representing the language code for this installation.
protocol = http
# Protocol (or scheme) used by your webserver (apache/nginx/…, can be http or https)
secret_key = ap6WerC2w8c6SGCPvFM5YDHdTXvBnzHcToS0J3r6LeetzReng6
# A secret key for a particular Django installation. This is used to provide cryptographic signing, and should be set to a unique, unpredictable value.
server_name = pythonnest.example.org
# the name of your webserver (should be a DNS name, but can be an IP address)
time_zone = Europe/Paris
# A string representing the time zone for this installation, or None.
[sentry]
dsn_url =
# Sentry URL to send data to. https://docs.getsentry.com/

If you need more complex settings, you can override default values (given in djangofloor.defaults and pythonnest.defaults) by creating a file named /home/pythonnest/.virtualenvs/pythonnest/etc/pythonnest/settings.py.

Debugging¶

If something does not work as expected, you can look at logs (in /var/log/supervisor if you use supervisor) or try to run the server interactively:

sudo service supervisor stop
sudo -u pythonnest -i
workon pythonnest
pythonnest-manage config
pythonnest-manage runserver
pythonnest-gunicorn

Backup¶

A complete PythonNest installation is made a different kinds of files:

the code of your application and its dependencies (you should not have to backup them),

static files (as they are provided by the code, you can lost them),

configuration files (you can easily recreate it, or you must backup it),

database content (you must backup it),

user-created files (you must also backup them).

Many backup strategies exist, and you must choose one that fits your needs. We can only propose general-purpose strategies.

We use logrotate to backup the database, with a new file each day.

sudo mkdir -p /var/backups/pythonnest
sudo chown -r pythonnest: /var/backups/pythonnest
sudo -u pythonnest -i
cat << EOF > /home/pythonnest/.virtualenvs/pythonnest/etc/pythonnest/backup_db.conf
/var/backups/pythonnest/backup_db.sql.gz {
  daily
  rotate 20
  nocompress
  missingok
  create 640 pythonnest pythonnest
  postrotate
  myproject-manage dumpdb | gzip > /var/backups/pythonnest/backup_db.sql.gz
  endscript
}
EOF
touch /var/backups/pythonnest/backup_db.sql.gz
crontab -e
MAILTO=admin@pythonnest.example.org
0 1 * * * /home/pythonnest/.virtualenvs/pythonnest/bin/pythonnest-manage clearsessions
0 2 * * * logrotate -f /home/pythonnest/.virtualenvs/pythonnest/etc/pythonnest/backup_db.conf

Backup of the user-created files can be done with rsync, with a full backup each month: If you have a lot of files to backup, beware of the available disk place!

sudo mkdir -p /var/backups/pythonnest/media
sudo chown -r pythonnest: /var/backups/pythonnest
cat << EOF > /home/pythonnest/.virtualenvs/pythonnest/etc/pythonnest/backup_media.conf
/var/backups/pythonnest/backup_media.tar.gz {
  monthly
  rotate 6
  nocompress
  missingok
  create 640 pythonnest pythonnest
  postrotate
  tar -C /var/backups/pythonnest/media/ -czf /var/backups/pythonnest/backup_media.tar.gz .
  endscript
}
EOF
touch /var/backups/pythonnest/backup_media.tar.gz
crontab -e
MAILTO=admin@pythonnest.example.org
0 3 * * * rsync -arltDE /var/pythonnest/data/media/ /var/backups/pythonnest/media/
0 5 0 * * logrotate -f /home/pythonnest/.virtualenvs/pythonnest/etc/pythonnest/backup_media.conf

Restoring a backup¶

cat /var/backups/pythonnest/backup_db.sql.gz | gunzip | /home/pythonnest/.virtualenvs/pythonnest/bin/pythonnest-manage dbshell
tar -C /var/pythonnest/data/media/ -xf /var/backups/pythonnest/backup_media.tar.gz

Monitoring¶

Nagios or Shinken¶

You can use Nagios checks to monitor several points:

connection to the application server (gunicorn or uwsgi):

connection to the database servers (PostgreSQL),

connection to the reverse-proxy server (apache or nginx),

the validity of the SSL certificate (can be combined with the previous check),

creation date of the last backup (database and files),

living processes for gunicorn, postgresql, apache,

standard checks for RAM, disk, swap…

Here is a sample NRPE configuration file:

cat << EOF | sudo tee /etc/nagios/nrpe.d/pythonnest.cfg
command[pythonnest_wsgi]=/usr/lib/nagios/plugins/check_http -H localhost -p 8130
command[pythonnest_database]=/usr/lib/nagios/plugins/check_tcp -H localhost -p 5432
command[pythonnest_reverse_proxy]=/usr/lib/nagios/plugins/check_http -H pythonnest.example.org -p 80 -e 401
command[pythonnest_backup_db]=/usr/lib/nagios/plugins/check_file_age -w 172800 -c 432000 /var/backups/pythonnest/backup_db.sql.gz
command[pythonnest_backup_media]=/usr/lib/nagios/plugins/check_file_age -w 3024000 -c 6048000 /var/backups/pythonnest/backup_media.sql.gz
command[pythonnest_gunicorn]=/usr/lib/nagios/plugins/check_procs -C python -a '/home/pythonnest/.virtualenvs/pythonnest/bin/pythonnest-gunicorn'
EOF

Sentry¶

For using Sentry to log errors, you must add raven.contrib.django.raven_compat to the installed apps.

[global]
extra_apps = raven.contrib.django.raven_compat
[sentry]
dsn_url = https://[key]:[secret]@app.getsentry.com/[project]

Of course, the Sentry client (Raven) must be separately installed, before testing the installation:

sudo -u pythonnest -i
pythonnest-manage raven test

LDAP groups¶

There are two possibilities to use LDAP groups, with their own pros and cons:

on each request, use an extra LDAP connection to retrieve groups instead of looking in the SQL database,

regularly synchronize groups between the LDAP server and the SQL servers.

The second approach can be used without any modification in your code and remove a point of failure in the global architecture (if you allow some delay during the synchronization process). A tool exists for such synchronization: MultiSync.