add simple view

app/e11sync/settings.py

@@ -104,3 +104,17 @@ COMPRESS_PRECOMPILERS = (
 )
 
 DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
+
+LOGGING = {
+    "version": 1,
+    "disable_existing_loggers": False,
+    "handlers": {
+        "console": {
+            "class": "logging.StreamHandler",
+        },
+    },
+    "root": {
+        "handlers": ["console"],
+        "level": "WARNING",
+    },
+}

app/lib/anonymize_ip.py

@@ -0,0 +1,105 @@
+# https://raw.githubusercontent.com/samuelmeuli/anonymize-ip/7f4faedf64643bd3de3607ab8905c1b1a3f8841a/anonymizeip/anonymize_ip.py
+
+from ipaddress import ip_address
+
+
+def anonymize_ip(
+    address,
+    ipv4_mask="255.255.255.0",
+    ipv6_mask="ffff:ffff:ffff:ffff:0000:0000:0000:0000"
+):
+    """
+    Anonymize the provided IPv4 or IPv6 address by setting parts of the
+    address to 0
+
+    :param str|int address: IP address to be anonymized
+    :param str ipv4_mask: Mask that defines which parts of an IPv4 address are
+    set to 0 (default: "255.255.255.0")
+    :param str ipv6_mask: Mask that defines which parts of an IPv6 address are
+    set to 0 (default: "ffff:ffff:ffff:ffff:0000:0000:0000:0000")
+    :return: Anonymized IP address
+    :rtype: str
+    """
+
+    # IP address to be anonymized
+    address_packed = ip_address(address).packed
+    address_len = len(address_packed)
+
+    if address_len == 4:
+        # IPv4
+        ipv4_mask_packed = ip_address(ipv4_mask).packed
+        __validate_ipv4_mask(ipv4_mask_packed)
+        return __apply_mask(address_packed, ipv4_mask_packed, 4)
+    elif address_len == 16:
+        # IPv6
+        ipv6_mask_packed = ip_address(ipv6_mask).packed
+        __validate_ipv6_mask(ipv6_mask_packed)
+        return __apply_mask(address_packed, ipv6_mask_packed, 16)
+    else:
+        # Invalid address
+        raise ValueError("Address does not consist of 4 (IPv4) or 16 (IPv6) "
+                         "octets")
+
+
+def __apply_mask(address_packed, mask_packed, nr_bytes):
+    """
+    Perform a bitwise AND operation on all corresponding bytes between the
+    mask and the provided address. Mask parts set to 0 will become 0 in the
+    anonymized IP address as well
+
+    :param bytes address_packed: Binary representation of the IP address to
+    be anonymized
+    :param bytes mask_packed: Binary representation of the corresponding IP
+    address mask
+    :param int nr_bytes: Number of bytes in the address (4 for IPv4, 16 for
+    IPv6)
+    :return: Anonymized IP address
+    :rtype: str
+    """
+
+    anon_packed = bytearray()
+    for i in range(0, nr_bytes):
+        anon_packed.append(mask_packed[i] & address_packed[i])
+    return str(ip_address(bytes(anon_packed)))
+
+
+def __validate_ipv4_mask(mask_packed):
+    # Test that mask only contains valid numbers
+    for byte in mask_packed:
+        if byte != 0 and byte != 255:
+            raise ValueError("ipv4_mask must only contain numbers 0 or 255")
+
+    # Test that IP address does not get anonymized completely
+    if mask_packed == b'\x00\x00\x00\x00':
+        raise ValueError("ipv4_mask cannot be set to \"0.0.0.0\" (all "
+                         "anonymized addresses will be 0.0.0.0)")
+
+    # Test that IP address is changed by anonymization
+    if mask_packed == b'\xff\xff\xff\xff':
+        raise ValueError("ipv4_mask cannot be set to \"255.255.255.255\" "
+                         "(addresses will not be anonymized)")
+
+
+def __validate_ipv6_mask(mask_packed):
+    # Test that mask only contains valid numbers
+    for byte in mask_packed:
+        if byte != 0 and byte != 255:
+            raise ValueError("ipv6_mask must only contain numbers 0 or ffff")
+
+    # Test that IP address does not get anonymized completely
+    if (
+        mask_packed ==
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+    ):
+        raise ValueError("ipv6_mask cannot be set to "
+                         "\"0000:0000:0000:0000:0000:0000:0000:0000\" (all "
+                         "anonymized addresses will be 0.0.0.0)")
+
+    # Test that IP address is changed by anonymization
+    if (
+        mask_packed ==
+        b'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff'
+    ):
+        raise ValueError("ipv6_mask cannot be set to "
+                         "\"ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff\" "
+                         "(addresses will not be anonymized)")

app/signup/templates/signup/index.html

@@ -77,12 +77,18 @@
   <form class="pure-form pure-form-aligned" action="{% url "index" %}" method="post">
     <fieldset>
       {% csrf_token %}
-      {% comment %}
-        <span class="pure-form-message message-error">{{ .Err }}</span>
+
+      {% if error_message %}
+        <span class="pure-form-message message-error">{{ error_message }}</span>
+      {% elif request.GET.success %}
         <span class="pure-form-message message-success">
-          You are now subscribed!
+          {% if request.GET.already_subscribed %}
+            Looks like you were already subscribed. We share your excitement!
+          {% else %}
+            You are now subscribed!
+          {% endif %}
         </span>
-      {% endcomment %}
+      {% endif %}
 
       <input type="email" class="subscribe-email" name="email" id="email" placeholder="your@email.com" required />
 

app/signup/tests.py

@@ -1,3 +1,21 @@
-from django.test import TestCase
+from django.test import TestCase, Client
+
+from django.urls import reverse
+
+def SignupViewTests(TestCase):
+    def setUp(self):
+        self.client = Client()
+
+    def test_index(self):
+        resp = self.client.get(reverse("index"))
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(resp, "11sync is a privacy-respecting way")
+
+    def test_ok_signup(self):
+        resp = self.client.post(reverse("index"), {"email": "foo@example.com"},
+                                follow = True,
+                                HTTP_USER_AGENT = "foo-agent",
+                                REMOTE_ADDR = "127.0.0.2")
+        self.assertEqual(resp.redirect_chain, ('http://testserver/?success', 302))
+        self.assertContains(resp, "You are now subscribed!")
 
-# Create your tests here.

app/signup/views.py

@@ -1,4 +1,48 @@
-from django.shortcuts import render
+import logging
+
+from django.shortcuts import render, redirect
+from django.db import IntegrityError
+
+from lib.anonymize_ip import anonymize_ip
+
+from .models import Signup
+
+
+logger = logging.getLogger(__name__)
+
 
 def index(request):
+    if request.method == "POST":
+        x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
+        if x_forwarded_for:
+            ip = x_forwarded_for.split(',')[0]
+        else:
+            ip = request.META.get('REMOTE_ADDR')
+        anonymous_ip = anonymize_ip(ip)
+
+        e = Email(
+          email = request.POST.get("email"),
+          anonymized_ip = anonymous_ip,
+          user_agent = request.META["HTTP_USER_AGENT"],
+        )
+
+        try:
+            e.clean_fields()
+        except ValidationError as e:
+            return e.render(request, "signup/index.html",
+                            {"error_message": e.message})
+
+        logging.info("registering email={}".format(request.POST.get("email")))
+        try:
+            e.save()
+        except IntegrityError:
+            # email already registered, presumably
+            return redirect("index") + "?already_subscribed"
+        except DatabaseError:
+            logger.exception("database error when registering an email")
+            err =  "Sorry, database error. Please come back later."
+            return render(request, "signup/index.html",
+                          {"error_message": err})
+        return redirect("index") + "?success"
+
     return render(request, "signup/index.html", {})