Merge ~suligap/canonical-identity-provider:talisker-statsd into canonical-identity-provider:master

[Przemysław Suliga]

Prepare for talisker's statsd integration

- Bump statsd package version to 3.3.0 (required by talisker for
  configuring the statsd client)
- Add talisker.django.middleware

After this, talisker can be configured using a STATSD_DSN env var to
send out various metrics to statsd. Currently those will be timers and
counters for views; example counter:

    $prefix.wsgi.latency.account-index.GET.200

The middleware is needed for view name introspection, also for the
purposes of creating these metrics:
https://talisker.readthedocs.io/en/latest/django.html#metadata

This also results in an X-View-Name response header being added.
Example:

    X-View-Name: account-index

Enabling the metrics sending part requires adding a proper STATSD_DSN
env var to talisker's execution env. Later more metrics can be added by
switching to use talisker provided `requests` session for example.

Maybe later, we can look into replacing the django_statsd based
PistonRequestTimingMiddleware metrics by these talisker provided ones.
They have a bit different naming structure (but it might be a win just
letting talisker decide here).

This depends on the new style middleware branch: https://code.launchpad.net/~suligap/canonical-identity-provider/+git/canonical-identity-provider/+merge/384550

[Maximiliano Bertacchini (maxiberta)]

+1

review: Approve

diff --git a/django_project/settings_base.py b/django_project/settings_base.py
index d131316..3ea4490 100644
--- a/django_project/settings_base.py
+++ b/django_project/settings_base.py
@@ -403,6 +403,7 @@ MIDDLEWARE = [
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
     'identityprovider.middleware.useraccount.UserAccountConversionMiddleware',
     'django.middleware.locale.LocaleMiddleware',
+    'talisker.django.middleware',
 ]
 
 MONTH_DAY_FORMAT = 'F j'
diff --git a/requirements.txt b/requirements.txt
index 60cc1e6..4e895fd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -40,7 +40,7 @@ requests-oauthlib==0.4.2
 saml2idp==0.18
 six==1.10.0
 ssoclient==2.1.1
-statsd==3.1
+statsd==3.3.0
 talisker[django,gunicorn,raven]==0.18.0
 testresources==0.2.7
 timeline==0.0.4