Django 1.9 instrumentation

Author: pglombardo

instana/django19.py

@@ -0,0 +1,50 @@
+from __future__ import print_function
+import opentracing as ot
+from instana import tracer, options
+import opentracing.ext.tags as ext
+
+
+DJ19_INSTANA_MIDDLEWARE = 'instana.django19.InstanaMiddleware19'
+
+
+class InstanaMiddleware19(object):
+    """ Django 1.9 Middleware to provide request tracing for Instana """
+    def __init__(self):
+        opts = options.Options(service="Django")
+        ot.global_tracer = tracer.InstanaTracer(opts)
+        self.span = None
+        self
+
+    def process_request(self, request):
+        env = request.environ
+        if 'HTTP_X_INSTANA_T' in env and 'HTTP_X_INSTANA_S' in env:
+            ctx = ot.global_tracer.extract(ot.Format.HTTP_HEADERS, env)
+            span = ot.global_tracer.start_span("django", child_of=ctx)
+        else:
+            span = ot.global_tracer.start_span("django")
+
+        span.set_tag(ext.HTTP_URL, env['PATH_INFO'])
+        span.set_tag("http.params", env['QUERY_STRING'])
+        span.set_tag(ext.HTTP_METHOD, request.method)
+        span.set_tag("http.host", env['HTTP_HOST'])
+        self.span = span
+
+    def process_response(self, request, response):
+        self.span.set_tag(ext.HTTP_STATUS_CODE, response.status_code)
+        ot.global_tracer.inject(self.span.context, ot.Format.HTTP_HEADERS, response)
+        self.span.finish()
+        return response
+
+
+
+def hook(module):
+    """ Hook method to install the Instana middleware into Django """
+    if DJ19_INSTANA_MIDDLEWARE in module.settings.MIDDLEWARE_CLASSES:
+        return
+
+    if type(module.settings.MIDDLEWARE_CLASSES) is tuple:
+        module.settings.MIDDLEWARE_CLASSES = (DJ19_INSTANA_MIDDLEWARE,) + module.settings.MIDDLEWARE_CLASSES
+    elif type(module.settings.MIDDLEWARE_CLASSES) is list:
+        module.settings.MIDDLEWARE_CLASSES = [DJ19_INSTANA_MIDDLEWARE] + module.settings.MIDDLEWARE_CLASSES
+    else:
+        print("Instana: Couldn't add InstanaMiddleware to Django")