zuul-web: key endpoint: return 404 when tenant or project not found

Fix the endpoint to remove 500 error when tenant or project is
not found.

Change-Id: I5fec37635cca8a697dba1c749d75c78bae24411c

tests/unit/test_web.py

@@ -267,6 +267,12 @@ class TestWeb(BaseTestWeb):
         self.assertEqual(resp.content, public_pem)
         self.assertIn('text/plain', resp.headers.get('Content-Type'))
 
+        resp = self.get_url("api/tenant/non-tenant/key/org/project.pub")
+        self.assertEqual(404, resp.status_code)
+
+        resp = self.get_url("api/tenant/tenant-one/key/org/no-project.pub")
+        self.assertEqual(404, resp.status_code)
+
     def test_web_404_on_unknown_tenant(self):
         resp = self.get_url("api/tenant/non-tenant/status")
         self.assertEqual(404, resp.status_code)

zuul/rpclistener.py

@@ -354,7 +354,12 @@ class RPCListener(object):
     def handle_key_get(self, job):
         args = json.loads(job.arguments)
         tenant = self.sched.abide.tenants.get(args.get("tenant"))
-        (trusted, project) = tenant.getProject(args.get("project"))
+        project = None
+        if tenant:
+            (trusted, project) = tenant.getProject(args.get("project"))
+        if not project:
+            job.sendWorkComplete("")
+            return
         job.sendWorkComplete(
             encryption.serialize_rsa_public_key(project.public_key))
 

zuul/web/__init__.py

@@ -289,6 +289,9 @@ class ZuulWebAPI(object):
     def key(self, tenant, project):
         job = self.rpc.submitJob('zuul:key_get', {'tenant': tenant,
                                                   'project': project})
+        if not job.data:
+            raise cherrypy.HTTPError(
+                404, 'Project %s does not exist.' % project)
         resp = cherrypy.response
         resp.headers['Access-Control-Allow-Origin'] = '*'
         resp.headers['Content-Type'] = 'text/plain'