Variables in webhook URLs. Fixes #52

hc/api/migrations/0026_auto_20160415_1824.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9 on 2016-04-15 18:24
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0025_auto_20160216_1214'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='channel',
+            name='value',
+            field=models.TextField(blank=True),
+        ),
+    ]

hc/api/models.py

@@ -117,10 +117,14 @@ class Channel(models.Model):
     user = models.ForeignKey(User)
     created = models.DateTimeField(auto_now_add=True)
     kind = models.CharField(max_length=20, choices=CHANNEL_KINDS)
-    value = models.CharField(max_length=200, blank=True)
+    value = models.TextField(blank=True)
     email_verified = models.BooleanField(default=False)
     checks = models.ManyToManyField(Check)
 
+    def assign_all_checks(self):
+        checks = Check.objects.filter(user=self.user)
+        self.checks.add(*checks)
+
     def make_token(self):
         seed = "%s%s" % (self.code, settings.SECRET_KEY)
         seed = seed.encode("utf8")
@@ -176,6 +180,18 @@ class Channel(models.Model):
         prio = int(prio)
         return user_key, prio, PO_PRIORITIES[prio]
 
+    @property
+    def value_down(self):
+        assert self.kind == "webhook"
+        parts = self.value.split("\n")
+        return parts[0]
+
+    @property
+    def value_up(self):
+        assert self.kind == "webhook"
+        parts = self.value.split("\n")
+        return parts[1] if len(parts) == 2 else ""
+
     def latest_notification(self):
         return Notification.objects.filter(channel=self).latest()
 

hc/api/tests/test_notify.py

@@ -64,6 +64,49 @@ class NotifyTestCase(BaseTestCase):
         n = Notification.objects.get()
         self.assertEqual(n.error, "Received status code 500")
 
+    @patch("hc.api.transports.requests.request")
+    def test_webhooks_support_variables(self, mock_get):
+        template = "http://host/$CODE/$STATUS/$TAG1/$TAG2/?name=$NAME"
+        self._setup_data("webhook", template)
+        self.check.name = "Hello World"
+        self.check.tags = "foo bar"
+        self.check.save()
+
+        self.channel.notify(self.check)
+
+        url = u"http://host/%s/down/foo/bar/?name=Hello%%20World" \
+            % self.check.code
+
+        mock_get.assert_called_with(
+            "get", url, headers={"User-Agent": "healthchecks.io"}, timeout=5)
+
+    @patch("hc.api.transports.requests.request")
+    def test_webhooks_dollarsign_escaping(self, mock_get):
+        # If name or tag contains what looks like a variable reference,
+        # that should be left alone:
+
+        template = "http://host/$NAME"
+        self._setup_data("webhook", template)
+        self.check.name = "$TAG1"
+        self.check.tags = "foo"
+        self.check.save()
+
+        self.channel.notify(self.check)
+
+        url = u"http://host/%24TAG1"
+        mock_get.assert_called_with(
+            "get", url, headers={"User-Agent": "healthchecks.io"}, timeout=5)
+
+    @patch("hc.api.transports.requests.request")
+    def test_webhook_fires_on_up_event(self, mock_get):
+        self._setup_data("webhook", "http://foo\nhttp://bar", status="up")
+
+        self.channel.notify(self.check)
+
+        mock_get.assert_called_with(
+            "get", "http://bar", headers={"User-Agent": "healthchecks.io"},
+            timeout=5)
+
     def test_email(self):
         self._setup_data("email", "[email protected]")
         self.channel.notify(self.check)

hc/api/transports.py

@@ -3,6 +3,7 @@ from django.template.loader import render_to_string
 from django.utils import timezone
 import json
 import requests
+from six.moves.urllib.parse import quote
 
 from hc.lib import emails
 
@@ -81,11 +82,33 @@ class HttpTransport(Transport):
 
 class Webhook(HttpTransport):
     def notify(self, check):
-        # Webhook integration only fires when check goes down.
-        if check.status != "down":
+        url = self.channel.value_down
+        if check.status == "up":
+            url = self.channel.value_up
+
+        if not url:
+            # If the URL is empty then we do nothing
             return "no-op"
 
-        return self.get(self.channel.value)
+        # Replace variables with actual values.
+        # There should be no bad translations if users use $ symbol in
+        # check's name or tags, because $ gets urlencoded to %24
+
+        if "$CODE" in url:
+            url = url.replace("$CODE", str(check.code))
+
+        if "$STATUS" in url:
+            url = url.replace("$STATUS", check.status)
+
+        if "$NAME" in url:
+            url = url.replace("$NAME", quote(check.name))
+
+        if "$TAG" in url:
+            for i, tag in enumerate(check.tags_list()):
+                placeholder = "$TAG%d" % (i + 1)
+                url = url.replace(placeholder, quote(tag))
+
+        return self.get(url)
 
     def test(self):
         return self.get(self.channel.value)

hc/front/forms.py

@@ -31,3 +31,13 @@ class AddChannelForm(forms.ModelForm):
     def clean_value(self):
         value = self.cleaned_data["value"]
         return value.strip()
+
+
+class AddWebhookForm(forms.Form):
+    error_css_class = "has-error"
+
+    value_down = forms.URLField(max_length=1000, required=False)
+    value_up = forms.URLField(max_length=1000, required=False)
+
+    def get_value(self):
+        return "{value_down}\n{value_up}".format(**self.cleaned_data)

hc/front/tests/test_add_channel.py

@@ -81,3 +81,31 @@ class AddChannelTestCase(BaseTestCase):
         params = "pushover_user_key=a&nonce=INVALID&prio=0"
         r = self.client.get("/integrations/add_pushover/?%s" % params)
         assert r.status_code == 403
+
+    def test_it_adds_two_webhook_urls_and_redirects(self):
+        form = {"value_down": "http://foo.com", "value_up": "https://bar.com"}
+
+        self.client.login(username="[email protected]", password="password")
+        r = self.client.post("/integrations/add_webhook/", form)
+        self.assertRedirects(r, "/integrations/")
+
+        c = Channel.objects.get()
+        self.assertEqual(c.value, "http://foo.com\nhttps://bar.com")
+
+    def test_it_rejects_non_http_webhook_urls(self):
+        form = {"value_down": "foo", "value_up": "bar"}
+
+        self.client.login(username="[email protected]", password="password")
+        r = self.client.post("/integrations/add_webhook/", form)
+        self.assertContains(r, "Enter a valid URL.")
+
+        self.assertEqual(Channel.objects.count(), 0)
+
+    def test_it_handles_empty_down_url(self):
+        form = {"value_down": "", "value_up": "http://foo.com"}
+
+        self.client.login(username="[email protected]", password="password")
+        self.client.post("/integrations/add_webhook/", form)
+
+        c = Channel.objects.get()
+        self.assertEqual(c.value, "\nhttp://foo.com")

hc/front/views.py

@@ -14,7 +14,8 @@ from django.utils.six.moves.urllib.parse import urlencode
 from hc.accounts.models import Profile
 from hc.api.decorators import uuid_or_400
 from hc.api.models import Channel, Check, Ping, DEFAULT_TIMEOUT, DEFAULT_GRACE
-from hc.front.forms import AddChannelForm, NameTagsForm, TimeoutForm
+from hc.front.forms import (AddChannelForm, AddWebhookForm, NameTagsForm,
+                            TimeoutForm)
 
 
 # from itertools recipes:
@@ -302,8 +303,7 @@ def do_add_channel(request, data):
         channel.user = request.user
         channel.save()
 
-        checks = Check.objects.filter(user=request.user)
-        channel.checks.add(*checks)
+        channel.assign_all_checks()
 
         if channel.kind == "email":
             channel.send_verify_link()
@@ -372,7 +372,19 @@ def add_email(request):
 
 @login_required
 def add_webhook(request):
-    ctx = {"page": "channels"}
+    if request.method == "POST":
+        form = AddWebhookForm(request.POST)
+        if form.is_valid():
+            channel = Channel(user=request.user, kind="webhook")
+            channel.value = form.get_value()
+            channel.save()
+
+            channel.assign_all_checks()
+            return redirect("hc-channels")
+    else:
+        form = AddWebhookForm()
+
+    ctx = {"page": "channels", "form": form}
     return render(request, "integrations/add_webhook.html", ctx)
 
 
@@ -454,6 +466,7 @@ def add_pushover(request):
     }
     return render(request, "integrations/add_pushover.html", ctx)
 
+
 @login_required
 def add_victorops(request):
     ctx = {"page": "channels"}

static/css/channels.css

@@ -169,4 +169,8 @@ table.channels-table > tbody > tr > th {
     border: ;
     max-width: 100%;
     border: 6px solid #EEE;
+}
+
+.variable-column {
+    width: 160px;
 }

templates/front/channel_checks.html

@@ -5,7 +5,7 @@
 
 <div class="modal-header">
     <button type="button" class="close" data-dismiss="modal">&times;</button>
-    <h4 class="update-timeout-title">Assign Checks to Channel {% if channel.kind == "po" %}{{ channel.po_value|join:" / " }}{% else %}{{ channel.value }}{% endif %}</h4>
+    <h4 class="update-timeout-title">Assign Checks to Channel</h4>
 </div>
 
 <input type="hidden" name="channel" value="{{ channel.code }}" />

templates/front/channels.html

@@ -28,23 +28,40 @@
             {% if ch.kind == "victorops" %} VictorOps {% endif %}
             </td>
             <td class="value-cell">
-                <span class="preposition">
-                {% if ch.kind == "email" %} to {% endif %}
-                {% if ch.kind == "pd" %} API key {% endif %}
-                {% if ch.kind == "po" %} user key {% endif %}
-                {% if ch.kind == "victorops" %} Post URL {% endif %}
-                </span>
-
-                {% if ch.kind == "po" %}
+                {% if ch.kind == "email" %}
+                    <span class="preposition">to</span>
+                    {{ ch.value }}
+                    {% if not ch.email_verified %}
+                        <span class="channel-unconfirmed">(unconfirmed)</span>
+                    {% endif %}
+                {% elif ch.kind == "pd" %}
+                    <span class="preposition">API key</span>
+                    {{ ch.value }}
+                {% elif ch.kind == "victorops" %}
+                    <span class="preposition">Post URL</span>
+                    {{ ch.value }}
+                {% elif ch.kind == "po" %}
+                    <span class="preposition">user key</span>
                     {{ ch.po_value|first }}
                     ({{ ch.po_value|last }} priority)
+                {% elif ch.kind == "webhook" %}
+                    <table>
+                        {% if ch.value_down %}
+                        <tr>
+                            <td class="preposition">down&nbsp;</td>
+                            <td>{{ ch.value_down }}</td>
+                        </tr>
+                        {% endif %}
+                        {% if ch.value_up %}
+                        <tr>
+                            <td class="preposition">up&nbsp;</td>
+                            <td>{{ ch.value_up }}</td>
+                        </tr>
+                        {% endif %}
+                    </table>
                 {% else %}
                     {{ ch.value }}
                 {% endif %}
-
-                {% if ch.kind == "email" and not ch.email_verified %}
-                <span class="channel-unconfirmed">(unconfirmed)
-                {% endif %}
             </td>
             <td class="channels-num-checks">
                 <a

templates/integrations/add_slack.html

@@ -55,7 +55,7 @@
         {% csrf_token %}
         <input type="hidden" name="kind" value="slack" />
         <div class="form-group">
-            <label for="inputEmail3" class="col-sm-2 control-label">Callback URL</label>
+            <label class="col-sm-2 control-label">Callback URL</label>
             <div class="col-sm-10">
                 <input type="text" class="form-control" name="value" placeholder="">
             </div>

templates/integrations/add_webhook.html

@@ -1,27 +1,84 @@
 {% extends "base.html" %}
 {% load compress humanize staticfiles hc_extras %}
 
-{% block title %}Add WebHook - healthchecks.io{% endblock %}
+{% block title %}Add Webhook - healthchecks.io{% endblock %}
 
 
 {% block content %}
 <div class="row">
 <div class="col-sm-12">
-    <h1>WebHook</h1>
+    <h1>Webhook</h1>
 
-    <p>WebHooks are a simple way to notify an external system when a check
-    goes down. healthcheks.io will run a normal HTTP GET call to your
+    <p>Webhooks are a simple way to notify an external system when a check
+    goes up or down. healthcheks.io will run a normal HTTP GET call to your
     specified URL.</p>
+    <p>You can use the following variables in webhook URLs:</p>
+    <table class="table webhook-variables">
+        <tr>
+            <th class="variable-column">Variable</th>
+            <td>Will be replaced with…</td>
+        </tr>
+        <tr>
+            <th><code>$CODE</code></th>
+            <td>The UUID code of the check</td>
+        </tr>
+        <tr>
+            <th><code>$NAME</code></th>
+            <td>Urlencoded name of the check</td>
+        </tr>
+        <tr>
+            <th><code>$STATUS</code></th>
+            <td>Check's current status ("up" or "down")</td>
+        </tr>
+        <tr>
+            <th><code>$TAG1, $TAG2, …</code></th>
+            <td>Urlencoded value of the first tag, the second tag, …</td>
+        </tr>
+    </table>
+
+    <p>For example, a callback URL using variables might look like so:
+    <pre>http://requestb.in/1hhct291?message=<strong>$NAME</strong>:<strong>$STATUS</strong></pre>
+
+    <p>
+        After encoding and replacing the variables, healthchecks.io would then call:
+    </p>
+    <pre>http://requestb.in/1hhct291?message=<strong>My%20Check</strong>:<strong>down</strong></pre>
 
     <h2>Integration Settings</h2>
 
-    <form method="post" class="form-horizontal" action="{% url 'hc-add-channel' %}">
+    <form method="post" class="form-horizontal">
         {% csrf_token %}
         <input type="hidden" name="kind" value="webhook" />
-        <div class="form-group">
-            <label for="inputEmail3" class="col-sm-2 control-label">URL</label>
-            <div class="col-sm-3">
-                <input type="text" class="form-control" name="value" placeholder="http://...">
+        <div class="form-group {{ form.value_down.css_classes }}">
+            <label class="col-sm-2 control-label">URL for "down" events</label>
+            <div class="col-sm-10">
+                <input
+                    type="text"
+                    class="form-control"
+                    name="value_down"
+                    placeholder="http://..."
+                    value="{{ form.value_down.value|default:"" }}">
+                {% if form.value_down.errors %}
+                <div class="help-block">
+                    {{ form.value_down.errors|join:"" }}
+                </div>
+                {% endif %}
+            </div>
+        </div>
+        <div class="form-group {{ form.value_up.css_classes }}">
+            <label class="col-sm-2 control-label">URL for "up" events</label>
+            <div class="col-sm-10">
+                <input
+                    type="text"
+                    class="form-control"
+                    name="value_up"
+                    placeholder="http://..."
+                    value="{{ form.value_up.value|default:"" }}">
+                {% if form.value_up.errors %}
+                <div class="help-block">
+                    {{ form.value_up.errors|join:"" }}
+                </div>
+                {% endif %}
             </div>
         </div>
         <div class="form-group">