Django backup strategy with dumps and migrations

Question

As with this question , I set up a backup system based on dumpdatafor my database. This setting is akin to running a cron script that invokes dumpdataand moves the backup to a remote server, for easy use loaddatato restore the database. However, I'm not sure if this works well with migrations . loaddatanow has a switch ignorenonexistentto handle remote models / fields, but it cannot allow cases where columns have been added with one-time default values ​​or apply code RunPython.

As I see, there are two problems:

• Mark each output file with the dumpdatacurrent version of each application
• Combining fixtures into a migration path

---

I'm at a dead end on how to solve the first problem without introducing tons of overhead. Would it be enough to save an additional file to a backup containing the mapping {app_name: migration_number}?

The second problem, which I think is easier when the first is solved, as the process is approximately equal:

• Create a new database
• Starting migration forward to the appropriate point for each application
• Call loaddatawith this fixture file
• Run the rest of the migration

There is some code in this question (related to the error message), which, I think, can be adapted for this purpose.

Since these are fairly regular / large database snapshots, I don’t want to save them as a data transfer cluttering up the migration directory.

Answer 1

, postgresql :

, , manage.py makemigrations .

, . , - . , .., .

, -as , before- , . :

• .
• .

. , .

, ( require.txt), , -of course- git .

1. dumpdata , . dumpdata , , :

   ./manage.py dumpdata --exclude auth.permission --exclude contenttypes  --exclude admin.LogEntry --exclude sessions --indent 2 > db.json
   

2. pg_dump :

   pg_dump -U $user -Fc $database --exclude-table=django_migrations > path/to/backup-dir/db.dump
   

3. , .

   migrations , :

   #!/bin/bash
   for dir in $(find -L -name "migrations")
   do
     rm -Rf $dir/*
   done
   

4. :

   , bash :

   su -l postgres -c "PGPASSWORD=$password psql -c 'drop database $database ;'"
   su -l postgres -c "createdb --owner $username $database"
   su -l postgres -c "PGPASSWORD=$password psql $database -U $username -c 'CREATE EXTENSION $extension ;'"
   

5. :

   pg_restore -Fc -U $username -d $database path/to/backup-dir/db.dump
   

6. 3, :

   ./manage.py makemigrations <app1> <app2> ... <appn>
   

   ... :

   #!/bin/bash
   apps=()
   for app in $(find ./ -maxdepth 1 -type d ! -path "./<project-folder> ! -path "./.*" ! -path "./")
   do
     apps+=(${app#??})
   done
   all_apps=$(printf "%s "  "${apps[@]}")
   
   ./manage.py makemigrations $all_apps
   

7. :

   ./manage.py migrate --fake
   

, - , *** ( ), , . db.json , :

pg_dump pg_restore

:

• 3 ( )
• 4 ( )
• 6 (makemigrations)

:

• :

  ./manage.py migrate
  

• db.json:

  ./manage.py loaddata path/to/db.json
  

, .

, .

, pg_dump pg_restore , .