software/nginx-push-stream: publish URITemplates instead of simple URL

URITemplate is more suitable because it also describe how we expect the clients
to pass parameters

software/nginx-push-stream/buildout.hash.cfg

@@ -8,4 +8,4 @@ md5sum = 022e4b53e1b2db16c4e518fe76f638fa
 
 [template-nginx]
 filename = instance-nginx.cfg.in
-md5sum = 565deec1e9678485cc8e542a54f5d076
+md5sum = 198bd472438989397bbf350f8361d316

software/nginx-push-stream/instance-nginx.cfg.in

@@ -72,5 +72,7 @@ config-url = $${nginx-configuration:base-url}/status
 
 [publish-connection-information]
 recipe = slapos.cookbook:publish
-publisher-url = $${nginx-configuration:base-url}/pub
-subscriber-url = $${nginx-configuration:base-url}/sub
+# publisher-url and subscriber-url are URITemplates, with an id
+# parameter which is the ID of the channel.
+publisher-url = $${nginx-configuration:base-url}/pub{?id}
+subscriber-url = $${nginx-configuration:base-url}/sub{/id}

software/nginx-push-stream/test/setup.py

@@ -44,6 +44,7 @@ setup(
         'slapos.core',
         'slapos.libnetworkcache',
         'requests',
+        'uritemplate',
     ],
     zip_safe=True,
     test_suite='test',

software/nginx-push-stream/test/test.py

@@ -28,6 +28,7 @@
 import os
 import multiprocessing
 
+import uritemplate
 import requests
 
 from slapos.testing.testcase import makeModuleSetUpAndTestCaseClass
@@ -46,7 +47,9 @@ class TestNginxPushStream(SlapOSInstanceTestCase):
     def process_messages(q):
       # type:(multiprocessing.Queue[bytes]) -> None
       req = requests.get(
-          self.connection_parameters['subscriber-url'] + '/channel_id',
+          uritemplate.URITemplate(
+              self.connection_parameters['subscriber-url']).expand(
+                  id='channel_id'),
           verify=False,
           stream=True,
       )
@@ -62,7 +65,9 @@ class TestNginxPushStream(SlapOSInstanceTestCase):
     self.assertEqual(q.get(timeout=30), b'ready')
 
     resp = requests.post(
-        self.connection_parameters['publisher-url'] + '?id=channel_id',
+        uritemplate.URITemplate(
+            self.connection_parameters['publisher-url']).expand(
+                id='channel_id'),
         verify=False,
         data='Hello',
         timeout=2,