Backend Removal Plan

Overview

This document provides step-by-step instructions for removing discussion-related backend code from the Django application.

Prerequisites

  1. Frontend removal completed (or on separate branch)
  2. Create git branch: git checkout -b remove-discussions-backend
  3. Database backup created
  4. Local development environment running

Phase 1: Update Dependent Apps First

Before removing the channels app entirely, update apps that depend on it.

1.1 Update Search App

File: search/constants.py

Changes:

# REMOVE this import
from channels.constants import COMMENT_TYPE, POST_TYPE

# ADD local definitions (to maintain backwards compatibility with existing indices)
POST_TYPE = "post"  # Keep constant for cleanup, mark as deprecated
COMMENT_TYPE = "comment"  # Keep constant for cleanup, mark as deprecated

# In VALID_OBJECT_TYPES, REMOVE:
# POST_TYPE,
# COMMENT_TYPE,

VALID_OBJECT_TYPES = (
    PROFILE_TYPE,
    COURSE_TYPE,
    PROGRAM_TYPE,
    USER_LIST_TYPE,
    STAFF_LIST_TYPE,
    VIDEO_TYPE,
    PODCAST_TYPE,
    PODCAST_EPISODE_TYPE,
)

# In MAPPING, REMOVE:
# POST_TYPE: {...},
# COMMENT_TYPE: {...},

# REMOVE CONTENT_OBJECT_TYPE definition entirely

File: search/serializers.py

Changes:

# REMOVE these imports
from channels.constants import COMMENT_TYPE, POST_TYPE
from channels.models import Comment, Post

# REMOVE these serializers
# class OSPostSerializer(...)
# class OSCommentSerializer(...)

File: search/search_index_helpers.py

Changes:

# REMOVE these imports
from channels.constants import COMMENT_TYPE, POST_TYPE, VoteActions
from channels.models import Comment
from channels.utils import render_article_text

# REMOVE these functions
# def serialize_post_for_bulk(...)
# def serialize_comment_for_bulk(...)
# def gen_post_id(...)
# def gen_comment_id(...)
# def update_post_text(...)
# def update_comment_text(...)
# Any reddit_object_* functions

File: search/api.py

Changes:

# REMOVE these imports
from channels.constants import (...)  # All channel-related imports
from channels.models import ChannelGroupRole

# In search filter logic, REMOVE:
# - Channel membership filtering
# - Channel type filtering
# - Any channel-related query modifications

File: search/tasks.py

Changes:

# REMOVE these imports
from channels.constants import COMMENT_TYPE, LINK_TYPE_LINK, POST_TYPE
from channels.models import Comment, Post

# REMOVE these tasks
# @app.task def index_posts(...)
# @app.task def index_comments(...)
# Any task that indexes posts/comments

1.2 Update Notifications App

File: notifications/notifiers/comments.py

Action: DELETE ENTIRE FILE

File: notifications/notifiers/__init__.py (or wherever notifiers are registered)

Changes: Remove import and registration of comment notifier

1.3 Update Profiles App

File: profiles/views.py

Changes:

# REMOVE these imports
from channels.models import Comment
from channels.proxies import proxy_posts
from channels.serializers.posts import BasePostSerializer
from channels.serializers.comments import BaseCommentSerializer
from channels.utils import (...)

# In profile views, REMOVE:
# - User posts section
# - User comments section
# - Any channel membership display

File: profiles/api.py

Changes:

# REMOVE this import
from channels.models import ChannelGroupRole

# Remove any channel role queries

1.4 Update Mail App

File: mail/ (various templates and views)

Changes:

  • Remove discussion subscription email templates
  • Remove frontpage email logic (if it sends post summaries)
  • Remove comment notification emails
  • Keep: General system emails

Phase 2: Remove URL Patterns

2.1 Update Main URLs

File: open_discussions/urls.py

Changes:

# REMOVE these imports
from open_discussions.views import channel_post, channel_redirect

# REMOVE these URL patterns
re_path(r"", include("channels.urls")),
re_path(r"", include("channels_fields.urls")),

re_path(r"^c/(?P<channel_name>[A-Za-z0-9_]+)/(?P<post_id>[A-Za-z0-9_]+)/"
        r"(?P<post_slug>{post_slug_pattern})/comment/(?P<comment_id>[A-Za-z0-9_]+)/?$",
        channel_post, name="channel-post-comment"),

re_path(r"^c/(?P<channel_name>[A-Za-z0-9_]+)/(?P<post_id>[A-Za-z0-9_]+)/"
        r"(?P<post_slug>{post_slug_pattern})/?$",
        channel_post, name="channel-post"),

re_path(r"^c/(?P<channel_name>[A-Za-z0-9_]+)/$", index, name="channel"),

re_path(r"^manage/c/edit/(?P<channel_name>[A-Za-z0-9_]+)/basic/$",
        index, name="manage-channel"),

re_path(r"^c/", index),
re_path(r"^channel/", channel_redirect),
re_path(r"^manage/", index),
re_path(r"^create_post/", index),

# REMOVE POST_SLUG_PATTERN if not used elsewhere

2.2 Update View Functions

File: open_discussions/views.py

Changes:

# REMOVE these functions
# def channel_post(...)
# def channel_redirect(...)

Phase 3: Remove Middleware

File: open_discussions/middleware/channel_api.py

Action: DELETE ENTIRE FILE

File: open_discussions/settings.py

Changes:

# In MIDDLEWARE, REMOVE:
"open_discussions.middleware.channel_api.ChannelApiMiddleware",

Phase 4: Update Settings

File: open_discussions/settings.py

Changes:

# In INSTALLED_APPS, REMOVE:
"channels",
"channels_fields",
# Consider removing if not used:
# "discussions",  # Verify usage first

# Remove any channel-specific settings
# Remove Reddit API settings
# Remove Akismet settings (if only used for discussions)

File: open_discussions/settings_celery.py

Changes:

# In CELERY_BEAT_SCHEDULE, REMOVE:
# - update-discussions
# - update-discussion-channels  
# - update-discussion-posts
# - spam-check tasks
# - subscription email tasks
# Any other discussion-related periodic tasks

Phase 5: Remove Django Apps

5.1 Remove Channels App 

# Remove the entire channels directory
rm -rf channels/

Files Removed:

  • channels/models.py - All discussion models
  • channels/api.py - Reddit API integration
  • channels/tasks.py - Celery tasks
  • channels/views/ - All API views
  • channels/serializers/ - All serializers
  • channels/admin.py - Admin configuration
  • channels/urls.py - URL patterns
  • channels/utils.py - Utilities
  • channels/proxies.py - Proxy objects
  • channels/spam.py - Spam checking
  • channels/factories/ - Test factories
  • All tests and migrations

5.2 Remove Channels Fields App 

# Remove the entire channels_fields directory
rm -rf channels_fields/

5.3 Remove or Update Discussions App

Action: First verify if this app is in use

# Check for imports
grep -r "from discussions" --include="*.py" . | grep -v ".venv" | grep -v test

# If not in use, remove it
rm -rf discussions/

If in use: Update to remove Reddit-backed functionality while keeping any standalone features.

Phase 6: Remove Embedly Integration (if applicable)

Check Usage:

grep -r "embedly" --include="*.py" . | grep -v ".venv" | grep -v test | grep -v channels

If only used for discussion link previews:

rm -rf embedly/

In settings.py:

# REMOVE from INSTALLED_APPS if removed
# Remove Embedly API key settings

Phase 7: Clean Up Fixtures and Test Data 

# Remove Reddit-specific fixtures
rm fixtures/reddit.py

# Update common fixtures
# File: fixtures/common.py

File: fixtures/common.py

Changes:

# REMOVE
# - mock_reddit_object_indexer
# - Any Reddit-related mocking

Phase 8: Update Authentication (if needed)

File: authentication/ (various)

Check: If any authentication logic is tied to channel membership or Reddit

Action: Remove or update as needed

Phase 9: Remove Python Dependencies

File: pyproject.toml

Changes:

# REMOVE these dependencies
# praw = "..."
# prawcore = "..."
# base36 = "..."
# akismet = "..."  # If only used for discussions

Run:

poetry lock
poetry install

Phase 10: Build and Test Backend

10.1 Check for Import Errors 

python manage.py check

Fix any import errors or missing references.

10.2 Run Migrations Check 

python manage.py makemigrations --dry-run

Should show no pending migrations yet (migrations come in next phase).

10.3 Run Tests 

# Run tests for preserved apps
pytest search/
pytest course_catalog/
pytest profiles/

# Check for failures related to removed code
pytest

Fix failures by:

  1. Removing tests for deleted functionality
  2. Updating imports
  3. Removing discussion-related assertions

10.4 Start Development Server 

python manage.py runserver

Verify:

  • ✅ Server starts without errors
  • ✅ Admin interface loads
  • ✅ No import errors in logs

10.5 Test API Endpoints 

# Test preserved endpoints
curl http://localhost:8000/api/v0/search/
curl http://localhost:8000/api/v0/podcasts/
curl http://localhost:8000/api/v0/courses/

# Verify removed endpoints return 404
curl http://localhost:8000/api/v0/channels/  # Should 404
curl http://localhost:8000/api/v0/posts/     # Should 404

Phase 11: Update Admin Interface

File: open_discussions/admin.py (or main admin config)

Changes: Remove any channel/post/comment admin registrations if they’re referenced

Phase 12: Clean Up Management Commands 

# Check for channel-related management commands
find . -path "*/management/commands/*" -name "*.py" | xargs grep -l "channel\|post\|comment" | grep -v ".venv"

Action: Remove or update any management commands that:

  • Sync with Reddit
  • Manage channels
  • Import posts/comments
  • Run spam checks on discussions

Phase 13: Update Documentation

Files to Update:

  • README.md - Remove Reddit setup instructions
  • docs/ - Remove discussion-related documentation
  • API documentation - Remove discussion endpoints

Environment Variables to Remove

Document these for production deployment:

# Remove from .env and deployment configs
OPEN_DISCUSSIONS_REDDIT_URL
OPEN_DISCUSSIONS_REDDIT_CLIENT_ID  
OPEN_DISCUSSIONS_REDDIT_SECRET
AKISMET_API_KEY
AKISMET_BLOG_URL
# Any other discussion-specific variables

Checklist

Before proceeding to database migrations:

  • Search app updated (no channels imports)
  • Notifications app updated
  • Profiles app updated
  • Mail app updated
  • URL patterns updated
  • Middleware removed
  • Settings updated
  • channels/ app removed
  • channels_fields/ app removed
  • discussions/ app handled
  • embedly/ handled (if applicable)
  • Fixtures updated
  • Python dependencies removed
  • Tests pass (preserved functionality)
  • Server starts without errors
  • API endpoints verified
  • Admin interface works
  • Management commands updated
  • Documentation updated
  • Changes committed to git

Rollback Plan

If issues arise:

# Return to previous state
git checkout main
git branch -D remove-discussions-backend

# Or revert specific commits
git revert <commit-hash>

# Restore Python environment
poetry install

Next Steps

Proceed to 04-database-migration.md for database cleanup instructions.

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