go mod download

go build -o main .

# ./main ${EMAIL_TEMPLATE_PATH} ${CUSTOMER_PATH} ${OUTPUT_DIR} ${ERROR_PATH}
# Example
./main assets/email_template.json \
  assets/customers.csv \
  output error/errors.csv

docker build -t go-mailer .

docker run --name go-mailer \
  --rm --privileged \
  -v /$(pwd)/assets:/assets:ro \
  -v /$(pwd)/error:/error \
  -v /$(pwd)/output:/output \
  go-mailer \
  assets/email_template.json \
  assets/customers.csv output \
  error/errors.csv

go test ./...