CommCare Utils

A Rails application for syncing data from CommCare HQ to external PostgreSQL databases. This tool enables automated data forwarding and scheduled syncing of CommCare case data to destination databases with support for sensitive field hashing and custom table mappings.

Overview

CommCare Utils acts as a bridge between CommCare HQ and external databases, providing:

• Real-time data forwarding via webhooks from CommCare
• Scheduled batch syncing of case data from CommCare export tables
• Sensitive field protection through one-way hashing
• Dynamic schema management with automatic table and column creation
• Token-based API authentication for secure webhook endpoints

Getting Started

Prerequisites

• Ruby 3.4.3
• PostgreSQL
• CommCare HQ account with API access

Installation

1. Clone the repository:

git clone <repository-url>
cd commcare-utils

2. Install dependencies:

bundle install

3. Set up the database:

bin/rails db:create
bin/rails db:migrate

4. Configure environment variables (create a .env file), see .env.example for required variables

Running Locally

For local development, use Procfile.dev which includes the web server, CSS compiler, and background worker:

bin/dev

This starts:

• web: Puma web server on port 3000
• css: DartSass CSS compiler in watch mode
• worker: GoodJob background worker for processing async jobs

Deployment

The application is configured for Heroku deployment using the Procfile:

git push heroku main

The Procfile includes:

• web: Puma web server
• worker: GoodJob background worker
• release: Automatic database migrations on deploy

Data Models

Destination

Represents a target database and CommCare project configuration.

Key attributes:

• name - Friendly name for the destination
• project_name - CommCare project name
• database_url - PostgreSQL connection string (encrypted)
• commcare_username - CommCare API username
• commcare_password - CommCare API key (encrypted)

Relationships:

• has_many :destination_sources - Data sources to sync
• has_many :destination_tokens - API tokens for webhook authentication

Methods:

• handle_forwarded_case(case_id) - Process a forwarded case from CommCare webhook
• commcare_client - Returns configured CommCare API client

DestinationSource

Represents a specific case type or data export from CommCare that should be synced to a table.

Key attributes:

• name - Friendly name for the source
• case_type - CommCare case type (for case-based syncing)
• url - CommCare export URL for table-based syncing
• table_name - Target table name in destination database
• key_column - Primary key column for upserts
• sensitive_fields - Comma-separated list of fields to hash
• scheduled_sync - Enable/disable scheduled batch syncing

Relationships:

• belongs_to :destination

Methods:

• sync_source - Sync data from CommCare export URL to destination table
• sync_case(case_data, owner, opened_by_user, closed_by_user) - Sync a single case with metadata

Includes:

• TableWritable concern - Provides database writing and table management functionality

DestinationToken

API tokens for authenticating webhook requests from CommCare.

Key attributes:

• token - UUID token (auto-generated)
• last_accessed_at - Timestamp of last use

Relationships:

• belongs_to :destination

Methods:

• self.authenticate(token_string) - Validate and return token
• touch_last_accessed - Update last access timestamp (rate-limited to 1 minute)

User

Application users authenticated via passwordless email login.

Key attributes:

• email - User email address (unique)

Authentication: Uses the passwordless gem for magic link email authentication.

Background Jobs

SyncSourceJob

Syncs a single DestinationSource from CommCare to the destination database.

Usage:

SyncSourceJob.perform_later(destination_source_id)

SyncAllSourcesJob

Queues sync jobs for all DestinationSource records with scheduled_sync: true.

Usage:

SyncAllSourcesJob.perform_later

Can be scheduled via cron or GoodJob's built-in scheduler.

DataForwardJob

Processes real-time case data forwarded from CommCare webhooks.

Usage:

DataForwardJob.perform_later(destination_token_id, payload)

Supports both XML and JSON payload formats from CommCare.

Core Components

TableWritable (Concern)

Provides database table management and data syncing functionality for DestinationSource.

Key features:

• Dynamic table and column creation
• Type inference and coercion
• Upsert operations with conflict resolution
• Sensitive field hashing (SHA256, truncated to 15 chars)
• Automatic cleanup of stale records
• Streaming HTML table parsing from CommCare exports

Methods:

• ensure_table(columns, drop_columns) - Create/update table schema
• upsert_row(columns, values, time) - Insert or update a row
• delete_rows_updated_before(time) - Remove stale records
• parse_source(&block) - Stream and parse CommCare export HTML

DatabaseWriter

Low-level PostgreSQL database operations for destination databases.

Features:

• Direct PostgreSQL connection management
• Table and column DDL operations
• Type mapping and conversion
• Parameterized queries for safety

Type mapping:

• string → text
• integer → integer
• float → decimal
• datetime → timestamp without time zone

CommcareClient

HTTP client for CommCare HQ API.

Methods:

• get_case(case_id) - Fetch case data
• get_user(user_id) - Fetch user data
• get_location(location_id) - Fetch location data

Architecture

Data Flow

1. Webhook Flow (Real-time):

   • CommCare sends case update → Webhook endpoint
   • Validates DestinationToken
   • Queues DataForwardJob
   • Job fetches full case data via API
   • Syncs to destination database via sync_case

2. Scheduled Sync Flow (Batch):

   • SyncAllSourcesJob runs on schedule
   • Queues SyncSourceJob for each enabled source
   • Job streams HTML export from CommCare
   • Parses and upserts rows to destination database
   • Removes stale records

Security Features

• Encrypted credentials (database URLs, CommCare passwords)
• Token-based webhook authentication
• Sensitive field hashing (one-way SHA256)
• Parameterized SQL queries
• HTTP success validation before parsing

Tech Stack

• Framework: Rails 8.1
• Ruby: 3.4.3
• Database: PostgreSQL
• Job Queue: GoodJob (database-backed)
• Authentication: Passwordless (magic link email)
• Frontend: Hotwire (Turbo + Stimulus), Bootstrap 5
• CSS: DartSass
• Deployment: Heroku, Kamal (Docker)