django-migrations-diff

CLI to compare Django migrations between two snapshots.

This may be useful when you need to compare migrations in the same app between different branches.

Installation

pip install django-migrations-diff

Requirements

• Python 3.6 or higher

How to use

# show help
mdiff help

# Create migrations snapshot
mdiff <snapshot>

# Compare two snapshots
mdiff <snapshot_1> <snapshot_2>

# Compare two snapshots (get number of diffent migrations)
mdiff <snapshot_1> <snapshot_2> --number

# List of all snapshots
mdiff list

# Remove all or specific snapshots
mdiff rm all
mdiff rm <snapshot_1> <snapshot_2>

# Get current version
mdiff -v

Example

For example, you need to compare "master" and "develop" branches.

git checkout master # go to "master" branch

mdiff master # create "master" snapshot

git checkout develop # go to "develop" branch

mdiff develop # create "develop" shapshot

mdiff master develop # compare two snapshots

Output will be like:

┌─────────────┬───────────────────┬───────────────────┐
│ APPLICATION │ MASTER            │ DEVELOP           │
├─────────────┼───────────────────┼───────────────────┤
│ app.authors │ 0004_migration.py │ ---               │
│             │ ---               │ 0005_migration.py │
├─────────────┼───────────────────┼───────────────────┤
│ app.users   │ 0003_migration.py │ 0003_migration.py │
└─────────────┴───────────────────┴───────────────────┘
 Stats for snapshot DEVELOP: +1 -1 *1

Explanation:

1. Snapshot MASTER has 0004_migration.py but DEVELOP misses it
2. Snapshot DEVELOP has 0005_migration.py but MASTER misses it
3. Both MASTER and DEVELOP have 0003_migration.py migration, but it differs inside
4. Stats show that DEVELOP snapshot has 1 new, 1 missing and 1 changed migration

CI/CD configuration

This package also can be used to detect new migrations in CI/CD pipelines. For example, following stage in .gitlab-ci.yml will fail if there are new migrations in current branch in comparison to master branch.

chechcheck:
  stage: tests
  script:
    - pip install django-migrations-diff==2.0.4  # PLEASE, CHECK CURRENT VERSION
    - git merge-base origin/master HEAD | xargs git checkout
    - mdiff master
    - git checkout ${CI_COMMIT_REF_NAME}
    - mdiff ${CI_COMMIT_REF_NAME}
    - mdiff master ${CI_COMMIT_REF_NAME}
    - (if [[ $(mdiff master ${CI_COMMIT_REF_NAME} --number) == 0 ]]; then echo "No new migrations"; else exit 1; fi;)
  allow_failure: true

NOTE: This is not full stage descriptions, this is only example.