mail-service

Microservice that leverages the Gmail API to send emails programmatically.

This requires a Service Account to be setup in GCP with Domain-wide delegation enabled. See here for more details.

Development

1. Copy the GCP Service Account's credentials file (sa_creds.json) into the root directory of the project. You can find this in LastPass.

2. Ensure the environment variables are set correctly in docker-compose.yaml.

3. Start the development server

This builds the Docker image and runs it automatically with the config defined in docker-compose.yaml. This saves you having to build the docker image and then run a manual docker run command with all the flags (for environment variables, ports, etc).

docker compose up

Deploying to Production

Will need to be behind an NGINX reverse proxy for security.

Flask is a WSGI application. A WSGI server is used to run the application, converting incoming HTTP requests to the standard WSGI environ, and converting outgoing WSGI responses to HTTP responses.

WSGI servers have HTTP servers built-in. However, a dedicated HTTP server may be safer, more efficient, or more capable. Putting an HTTP server in front of the WSGI server is called a “reverse proxy.”

-- Flask Documentation

1. Copy the GCP Service Account's credentials file (sa_creds.json) into the root directory of the project. You can find this in LastPass. Yes, this file gets baked into the container. This is a temporary solution until we can figure out a better way to do this, but Google's authentication & auth client libraries are complicated and annoying.

2. Build and run the production image.

# Build Docker image for production:
docker build -t mail-service-api .

# Example manually running a container with environment variables and ports defined:
docker run -p 8080:80 -e SA_CREDS_LOCATION=sa_creds.json mail-service-api

API Contract

Health check

GET /

Send Email

POST /v1/send

Request headers

Request Body

{
	"recipient": string, 		// recipient's email address
	"subject": string, 			// email subject
	"base64_content": string 	// email body (base64 encoded)
}