django-check-migration-wtf

Description

django-check-migration-wtf is an extension for Django to check migrations and notify you if their are secure to do on environments with zero downtime.

In some situations Django Migration system generate migrations to need do a downtime because they are blocking operation or you write custom migration than can block you database.

Actually this extension only works for backends of PostgresSQL and Postgis.

Advise: this extension notify you for common blocking operations on database. Anyway you should review your migrations and understand their.

Configuration

It is really simple

Installation

Install the package with the typical tool (pip):

pip install django-check-migration-wtf

Add to your project

Add app on your settings:

INSTALLED_APPS = [
    'django_check_migration_wtf',
    ...,
]

Add some optional vars

Add some optional setup on your settings:

• CHECK_MIGRATION_WTF_PSQL_VERSION It is to know your PostgresSQL Version by default it is 9
• The next following vars are for use github integration:
  • CHECK_MIGRATION_WTF_GITHUB_TOKEN Token to can use API of github, It only need permission of reading of repo.
  • CHECK_MIGRATION_WTF_REPO_NAME Name of repository on Github

Usage

It is really easy to use. It is execute by a typical django command like makemigrations or migrate... It has two mode of usage.

Local

First execute your makemigrations and you can do your custome modifications. Then before execute command migrate execute the following command:

python manage.py check_migration

It will search all migrations that are not apply to the system (like showmigrations) and it will analyze if they are secure to do.

You can have two possibilities:

• When the migration or migrations are secure, you get the following response:

  

• When the migration or migrations are not secure, you get the following response:

  

Github

This is reality an option of command to execute it on your continues integration. It will search you migrations comparing the base branch and your current branch and the analyze it

python manage.py check_migration --github <head_ref> <base_ref>

Limitations

• This extension not analyze code inside of RunPython
• Github option to work correctly suppose your migrations are inside of directory migrations