refactor invoiceworker to be run by uwsgi, support graceful shutdown, and support reloading code without exiting

src/shop/invoiceworker.py

@@ -0,0 +1,65 @@
+from django.core.files import File
+from django.conf import settings
+from django.utils import timezone
+from shop.pdf import generate_pdf_letter
+from shop.email import send_invoice_email, send_creditnote_email
+from shop.models import Order, CustomOrder, Invoice, CreditNote
+from decimal import Decimal
+import logging
+
+
+def run_invoice_worker():
+    logging.basicConfig(level=logging.INFO)
+    logger = logging.getLogger(__name__)
+
+    # check if we need to generate any invoices for shop orders
+    for order in Order.objects.filter(paid=True, invoice__isnull=True):
+        # generate invoice for this Order
+        Invoice.objects.create(order=order)
+        logger.info('Generated Invoice object for %s' % order)
+
+    # check if we need to generate any invoices for custom orders
+    for customorder in CustomOrder.objects.filter(invoice__isnull=True):
+        # generate invoice for this CustomOrder
+        Invoice.objects.create(customorder=customorder)
+        logger.info('Generated Invoice object for %s' % customorder)
+
+    # check if we need to generate any pdf invoices
+    for invoice in Invoice.objects.filter(pdf=''):
+        # put the dict with data for the pdf together
+        formatdict = {
+            'invoice': invoice,
+        }
+
+        # generate the pdf
+        try:
+            if invoice.customorder:
+                template='pdf/custominvoice.html'
+            else:
+                template='pdf/invoice.html'
+            pdffile = generate_pdf_letter(
+                filename=invoice.filename,
+                template=template,
+                formatdict=formatdict,
+            )
+            logger.info('Generated pdf for invoice %s' % invoice)
+        except Exception as E:
+            logger.error('ERROR: Unable to generate PDF file for invoice #%s. Error: %s' % (invoice.pk, E))
+            continue
+
+        # so, do we have a pdf?
+        if not pdffile:
+            logger.error('ERROR: Unable to generate PDF file for invoice #%s' % invoice.pk)
+            continue
+
+        # update invoice object with the file
+        invoice.pdf.save(invoice.filename, File(pdffile))
+        invoice.save()
+
+    ###############################################################
+    # check if we need to send out any invoices (only for shop orders, and only where pdf has been generated)
+    for invoice in Invoice.objects.filter(order__isnull=False, sent_to_customer=False).exclude(pdf=''):
+        # send the email
+        if send_invoice_email(invoice=invoice):
+            logger.info('OK: Invoice email sent to %s' % invoice.order.user.email)
+

src/shop/management/commands/invoice-worker.py

@@ -1,119 +1,46 @@
 from django.core.management.base import BaseCommand
-from django.core.files import File
+from shop import invoiceworker
-from django.conf import settings
-from django.utils import timezone
-from shop.pdf import generate_pdf_letter
-from shop.email import send_invoice_email, send_creditnote_email
-from shop.models import Order, CustomOrder, Invoice, CreditNote
 from time import sleep
-from decimal import Decimal
+import signal, sys
+import logging
 
 
 class Command(BaseCommand):
     args = 'none'
     help = 'Generate invoices and credit notes, and email invoices that have not been sent yet'
+    exit = False
 
-    def output(self, message):
+    def __init__(self):
-        self.stdout.write('%s: %s' % (timezone.now().strftime("%Y-%m-%d %H:%M:%S"), message))
+        logging.basicConfig(level=logging.INFO)
+        self.logger = logging.getLogger('bornhack.%s' % __name__)
+
+    def reload_worker_code(self, signum, frame):
+        self.logger.info("Reloading shop.invoiceworker module...")
+        reload(invoiceworker)
+        self.logger.info("Done reloading shop.invoiceworker module")
+
+    def clean_exit(self, signum, frame):
+        self.logger.info("SIGTERM received, exiting gracefully soon...")
+        self.exit = True
 
     def handle(self, *args, **options):
-        self.output('Invoice worker running...')
+        self.logger.info("Connecting signals...")
+        signal.signal(signal.SIGHUP, self.reload_worker_code)
+        signal.signal(signal.SIGTERM, self.clean_exit)
+        signal.signal(signal.SIGINT, self.clean_exit)
+
+        self.logger.info("Entering main loop...")
         while True:
-            # check if we need to generate any invoices for shop orders
+            # run invoiceworker
-            for order in Order.objects.filter(paid=True, invoice__isnull=True):
+            invoiceworker.run_invoice_worker()
-                # generate invoice for this Order
-                Invoice.objects.create(order=order)
-                self.output('Generated Invoice object for %s' % order)
 
-            # check if we need to generate any invoices for custom orders
+            # sleep for 60 seconds, but check sys.exit every second
-            for customorder in CustomOrder.objects.filter(invoice__isnull=True):
+            i = 0
-                # generate invoice for this CustomOrder
+            while i < 60:
-                Invoice.objects.create(customorder=customorder)
+                if self.exit:
-                self.output('Generated Invoice object for %s' % customorder)
+                    self.logger.info("Graceful exit requested, calling sys.exit(0) now")
-
+                    sys.exit(0)
-            # check if we need to generate any pdf invoices
-            for invoice in Invoice.objects.filter(pdf=''):
-                # put the dict with data for the pdf together
-                formatdict = {
-                    'invoice': invoice,
-                }
-
-                # generate the pdf
-                try:
-                    if invoice.customorder:
-                        template='pdf/custominvoice.html'
                 else:
-                        template='pdf/invoice.html'
+                    i += 1
-                    pdffile = generate_pdf_letter(
+                    sleep(1)
-                        filename=invoice.filename,
-                        template=template,
-                        formatdict=formatdict,
-                    )
-                    self.output('Generated pdf for invoice %s' % invoice)
-                except Exception as E:
-                    self.output('ERROR: Unable to generate PDF file for invoice #%s. Error: %s' % (invoice.pk, E))
-                    continue
-
-                # so, do we have a pdf?
-                if not pdffile:
-                    self.output('ERROR: Unable to generate PDF file for invoice #%s' % invoice.pk)
-                    continue
-
-                # update invoice object with the file
-                invoice.pdf.save(invoice.filename, File(pdffile))
-                invoice.save()
-
-            ###############################################################
-            # check if we need to send out any invoices (only for shop orders, and only where pdf has been generated)
-            for invoice in Invoice.objects.filter(order__isnull=False, sent_to_customer=False).exclude(pdf=''):
-                # send the email
-                if send_invoice_email(invoice=invoice):
-                    self.output('OK: Invoice email sent to %s' % invoice.order.user.email)
-                    invoice.sent_to_customer=True
-                    invoice.save()
-                else:
-                    self.output('ERROR: Unable to send invoice email for order %s to %s' % (invoice.order.pk, invoice.order.user.email))
-
-            ###############################################################
-            # check if we need to generate any pdf creditnotes?
-            for creditnote in CreditNote.objects.filter(pdf=''):
-                # put the dict with data for the pdf together
-                formatdict = {
-                    'creditnote': creditnote,
-                }
-
-                # generate the pdf
-                try:
-                    pdffile = generate_pdf_letter(
-                        filename=creditnote.filename,
-                        template='pdf/creditnote.html',
-                        formatdict=formatdict,
-                    )
-                    self.output('Generated pdf for creditnote %s' % creditnote)
-                except Exception as E:
-                    self.output('ERROR: Unable to generate PDF file for creditnote #%s. Error: %s' % (creditnote.pk, E))
-                    continue
-
-                # so, do we have a pdf?
-                if not pdffile:
-                    self.output('ERROR: Unable to generate PDF file for creditnote #%s' % creditnote.pk)
-                    continue
-
-                # update creditnote object with the file
-                creditnote.pdf.save(creditnote.filename, File(pdffile))
-                creditnote.save()
-
-            ###############################################################
-            # check if we need to send out any creditnotes (only where pdf has been generated)
-            for creditnote in CreditNote.objects.filter(sent_to_customer=False).exclude(pdf=''):
-                # send the email
-                if send_creditnote_email(creditnote=creditnote):
-                    self.output('OK: Creditnote email sent to %s' % creditnote.user.email)
-                    creditnote.sent_to_customer=True
-                    creditnote.save()
-                else:
-                    self.output('ERROR: Unable to send creditnote email for creditnote %s to %s' % (creditnote.pk, creditnote.user.email))
-
-            # pause for a bit
-            sleep(60)