Bug 1065784 - Remove Django admin (#3170)

Since the only things we used it for were:
* editing users - but that doesn't work any more (bug 1346740) so
  requires a manual DB edit as is it, and we won't need to edit users
  at all once LDAP groups are used for permissions (bug 1273092)
* marking pending Hawk credentials as approved - however we're not
  accepting any new requests for Hawk credentials (bug 1433011)
* resetting the secret key for Hawk credentials - however we've not
  used this feature once in the entire time we've used Hawk - and its
  trivial via MySQLWorkbench.

As as added bonus removing Django admin:
* reduces the work required to add a CSP header
* speeds up `collectstatic` (which is run during deploy) by 30%
* reduces the risk of giving `is_staff` permissions (which have to be
  given to sheriffs, but also allowed admin access)
* reduces attack surface in general

In addition to the Django admin app, `django.contrib.messages` app
and the auth/messages context processors have been removed, since
after bug 1433011, admin was the only remaining consumer of them:
https://docs.djangoproject.com/en/1.11/ref/contrib/admin/

treeherder/config/settings.py

@@ -66,12 +66,6 @@ TEMPLATES = [
             path("templates"),
         ],
         'APP_DIRS': True,
-        'OPTIONS': {
-            'context_processors': [
-                'django.contrib.auth.context_processors.auth',
-                'django.contrib.messages.context_processors.messages',
-            ],
-        },
     },
 ]
 
@@ -90,7 +84,6 @@ MIDDLEWARE_CLASSES = [middleware for middleware in [
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
-    'django.contrib.messages.middleware.MessageMiddleware',
     'hawkrest.middleware.HawkResponseMiddleware',
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
 ] if middleware]
@@ -121,12 +114,10 @@ INSTALLED_APPS = [
     'django.contrib.auth',
     'django.contrib.contenttypes',
     'django.contrib.sessions',
-    'django.contrib.messages',
     # Disable Django's own staticfiles handling in favour of WhiteNoise, for
     # greater consistency between gunicorn and `./manage.py runserver`.
     'whitenoise.runserver_nostatic',
     'django.contrib.staticfiles',
-    'django.contrib.admin',
     # 3rd party apps
     'rest_framework',
     'rest_framework_swagger',

treeherder/config/urls.py

@@ -1,17 +1,13 @@
 from django.conf import settings
 from django.conf.urls import (include,
                               url)
-from django.contrib import admin
 from django.views.decorators.csrf import csrf_exempt
 from rest_framework_swagger.views import get_swagger_view
 
 from treeherder.webapp.api import urls as api_urls
 
-admin.site.login_template = 'webapp/admin_login.html'
-
 urlpatterns = [
    url(r'^api/', include(api_urls)),
-   url(r'^admin/', admin.site.urls),
    url(r'^docs/', get_swagger_view(title='Treeherder API')),
 ]
 

treeherder/webapp/admin.py

@@ -1,40 +0,0 @@
-from django.contrib import admin
-
-from treeherder.model.models import *
-from treeherder.perf.models import PerformanceFramework
-
-
-class JobTypeAdmin(admin.ModelAdmin):
-    list_display = ['name', 'symbol', 'description']
-    list_editable = ['symbol']
-
-
-class ReferenceDataSignatureAdmin(admin.ModelAdmin):
-    list_display = ["name", "signature", "build_os_name", "build_platform",
-                    "build_architecture", "machine_os_name", "machine_platform",
-                    "machine_architecture", "job_group_name", "job_group_symbol",
-                    "job_type_name", "job_type_symbol", "option_collection_hash", "build_system_type",
-                    "first_submission_timestamp"]
-
-    search_fields = ["name", "signature", "build_os_name", "build_platform",
-                     "build_architecture", "machine_os_name", "machine_platform",
-                     "machine_architecture", "job_group_name", "job_group_symbol",
-                     "job_type_name", "job_type_symbol", "option_collection_hash", "build_system_type"]
-
-
-# custom admin classes
-admin.site.register(JobType, JobTypeAdmin)
-admin.site.register(Repository)
-admin.site.register(ReferenceDataSignatures, ReferenceDataSignatureAdmin)
-# default admin classes
-admin.site.register(Product)
-admin.site.register(BuildPlatform)
-admin.site.register(Option)
-admin.site.register(RepositoryGroup)
-admin.site.register(MachinePlatform)
-admin.site.register(Bugscache)
-admin.site.register(Machine)
-admin.site.register(JobGroup)
-admin.site.register(OptionCollection)
-admin.site.register(FailureClassification)
-admin.site.register(PerformanceFramework)

treeherder/webapp/templates/webapp/admin_login.html

@@ -1,17 +0,0 @@
-{% extends "admin/base_site.html" %}
-{% block content %}
-<html>
-  <body>
-    <div>
-        {% if user.is_authenticated %}
-        <!--shouldn't see this page if you're logged in.  It should just go to admin-->
-            Current user: {{ user.email }} - {{ user.username}} - {{user.is_superuser}}
-            <div>Something went wrong.
-                 Try logging out and back in through the main <a href="/" target="_blank">Treeherder UI</a>.</div>
-        {% else %}
-            <div>Please login through the main <a href="/" target="_blank">Treeherder UI</a>.</div>
-        {% endif %}
-    </div>
-  </body>
-</html>
-{% endblock %}