The development Docker Compose stack runs PostgreSQL, RabbitMQ, database migrations, the Notification Service Web and Worker applications, Seq, and Mailpit.

Prerequisite: install and start Docker Desktop. Then run the installation script from the repository root:

.\docker\environments\install-development.cmd

The script validates Docker and the Compose configuration, builds the application images, starts the complete stack in the background, and prints container status and the main development URLs. It can also be launched directly from File Explorer or from another working directory.

To validate the setup without building images or creating containers, run:

.\docker\environments\install-development.cmd --validate-only

By default, the script uses the tracked docker/environments/.env.Development file:

DB_NAME=notification_service
DB_USER=postgres
DB_PASS=postgres
VOLUME_PREFIX=ns-dev
RABBITMQ_USER=guest
RABBITMQ_PASSWORD=guest
RABBITMQ_AMQP_PORT=5672
RABBITMQ_MANAGEMENT_PORT=15672
WEB_PORT=5200
DEVELOPMENT_EMAIL_SERVICE_NAME=TestService

To use personal values, copy it to the Git-ignored docker/environments/.env.local, adjust the values, and run Docker Compose manually:

docker compose --env-file docker/environments/.env.local `
  -f docker/environments/docker-compose.yml `
  -f docker/environments/docker-compose.Development.yml `
  up --build -d

After startup, the main development endpoints are:

Notification Service admin: http://localhost:5200/admin/channels
Notification templates: http://localhost:5200/admin/templates
RabbitMQ management: http://localhost:15672 (guest / guest)
Mailpit inbox: http://localhost:8025
Seq logs: http://localhost:5342
PostgreSQL: localhost:5433

During development migrations, the stack idempotently creates an active Mailpit SMTP channel and a neutral English TestEmail template for DEVELOPMENT_EMAIL_SERVICE_NAME. Existing channels and templates are never overwritten. Change that environment value when the publisher uses another service name.

Check container status and follow Worker logs:

docker compose --env-file docker/environments/.env.local `
  -f docker/environments/docker-compose.yml `
  -f docker/environments/docker-compose.Development.yml `
  ps

docker compose --env-file docker/environments/.env.local `
  -f docker/environments/docker-compose.yml `
  -f docker/environments/docker-compose.Development.yml `
  logs -f worker

Stop the environment without deleting its database and RabbitMQ volumes:

docker compose --env-file docker/environments/.env.local `
  -f docker/environments/docker-compose.yml `
  -f docker/environments/docker-compose.Development.yml `
  down

See the ItemTracker consumer guide for the complete end-to-end setup.

Notification worker flow

flowchart TD
    A[Worker host starts] --> B[Load config and register services]
    B --> C[Start SendEmailConsumer]
    C --> D[Receive message from notification.send-email]
    D --> E[Validate Notification.SendEmail.v1 metadata and payload]
    E --> F[Resolve SendEmailService]
    F --> G[Pick channel and exact-language template]
    G --> H[Validate variables and render email content]
    H --> I[Send via SMTP]
    I --> J[Update usage counters]
    J --> K[Optionally publish result to reply queue]
    K --> L[Acknowledge RabbitMQ delivery]
    I -. failure .-> M[Log and retry]
    M -->|retries exhausted| N[Publish terminal failure result]
    N --> O[Nack original delivery without requeue]

Template variables are treated as plain text. The worker HTML-encodes every variable while rendering HtmlBody; subject and plain-text body interpolation preserve the original value. Templates must express markup in body.html instead of supplying HTML through variables.