Fix: POST /project with an existing project name fails

6 files changed, 39 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 91e2186..a6cec8f 100644
--- a/NEWS
+++ b/NEWS
@@ -23,6 +23,9 @@ Version 0.17+git, not yet released
 * Add subommand `icktool status` which shows current status of every
   pipeline in every project.
 
+* `POST /projects` (or `icktool create-project`) with a project
+  description that names an already existing project fails.
+
 Version 0.17, released 2017-11-19
 ----------------------------------
 
diff --git a/ick2/__init__.py b/ick2/__init__.py
index abbde96..13912fe 100644
--- a/ick2/__init__.py
+++ b/ick2/__init__.py
@@ -18,12 +18,14 @@ from .logging import setup_logging, log
 from .state import ControllerState, NotFound, WrongPipelineStatus
 from .exceptions import (
     BadUpdate,
+    ExistsAlready,
     IckException,
     MethodNotAllowed,
 )
 from .responses import (
     OK,
     bad_request,
+    conflict,
     created,
     not_found,
     text_plain,
diff --git a/ick2/apibase.py b/ick2/apibase.py
index 7694b47..9795178 100644
--- a/ick2/apibase.py
+++ b/ick2/apibase.py
@@ -73,8 +73,11 @@ class APIbase:
             ick2.log.log(
                 'trace', msg_text='POST called', kwargs=kwargs,
                 content_type=content_type, body=body)
-            body = callback(body)
-            ick2.log.log('trace', msg_text='returned body', body=repr(body))
+            try:
+                body = callback(body)
+            except ick2.ExistsAlready as e:
+                ick2.log.log('error', msg_text=str(e))
+                return ick2.conflict(str(e))
             return ick2.created(body)
         return wrapper
 
@@ -144,8 +147,13 @@ class ResourceApiBase(APIbase):
         return self._state.get_resource(self._type_name, name)
 
     def create(self, body, **kwargs):
-        return self._state.add_resource(
-            self._type_name, self.get_resource_name(body), body)
+        name = self.get_resource_name(body)
+        try:
+            self._state.get_resource(self._type_name, name)
+        except ick2.NotFound:
+            return self._state.add_resource(self._type_name, name, body)
+        else:
+            raise ick2.ExistsAlready(name)
 
     def get_resource_name(self, resource):  # pragma: no cover
         raise NotImplementedError()
diff --git a/ick2/exceptions.py b/ick2/exceptions.py
index c99c3e5..124b207 100644
--- a/ick2/exceptions.py
+++ b/ick2/exceptions.py
@@ -18,6 +18,12 @@ class IckException(Exception):
     pass
 
 
+class ExistsAlready(IckException):
+
+    def __init__(self, name):
+        super().__init__('Resource {} already exists'.format(name))
+
+
 class BadUpdate(IckException):
 
     def __init__(self, how):
diff --git a/ick2/responses.py b/ick2/responses.py
index ef68783..1ceae52 100644
--- a/ick2/responses.py
+++ b/ick2/responses.py
@@ -58,3 +58,10 @@ def created(body):  # pragma: no cover
         'Content-Type': 'application/json',
     }
     return response(apifw.HTTP_CREATED, body, headers)
+
+
+def conflict(body):  # pragma: no cover
+    headers = {
+        'Content-Type': 'text/plain',
+    }
+    return response(apifw.HTTP_CONFLICT, body, headers)
diff --git a/yarns/100-projects.yarn b/yarns/100-projects.yarn
index 0aa57b0..de7f9c7 100644
--- a/yarns/100-projects.yarn
+++ b/yarns/100-projects.yarn
@@ -106,6 +106,15 @@ building them. We start by starting an instance of the controller.
     ... }
     AND controller state directory contains project website
 
+Creating a new project with the same name is forbidden.
+
+    WHEN user makes request POST /projects with a valid token and body
+    ... {
+    ...     "project": "website",
+    ...     "pipelines": []
+    ... }
+    THEN result has status code 409
+
     WHEN user makes request GET /projects
     THEN result has status code 200
     AND body matches