Error parsing yaml file: mapping values are not al

Question

I want to upload an app to Google App Engine:

I get this

Error parsing yaml file:
mapping values are not allowed here
  in "/home/antonio/Desktop/ATI/climate-change/app.yaml", line 2, column 8 

When running

./appcfg.py update /home/antonio/Desktop/ATI/climate-change

with this app.yaml file:

application:climate-change
version: 1
runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /.*
  script: helloworld.app

line 2, column 8 corresponds to the version line. What is wrong here? Btw, I'm using Ubuntu 12.04 here.

Answer 1

Another cause is wrong indentation which means trying to create the wrong objects. I've just fixed one in a Kubernetes Ingress definition:

Wrong

- path: / 
    backend: 
      serviceName: <service_name> 
      servicePort: <port> 

Correct

- path: /
  backend:
    serviceName: <service_name>
    servicePort: <port>

Answer 2

Change

application:climate-change

to

application: climate-change

The space after the colon is mandatory in yaml. (See http://www.yaml.org/spec/1.2/spec.html#id2759963)

Answer 3

Maybe this will help someone else, but I've seen this error when the RHS of the mapping contains a colon without enclosing quotes, such as:

someKey: another key: Change to make today: work out more

should be

someKey: another key: "Change to make today: work out more"

Answer 4

Or, if spacing is not the problem, it might want the parent directory name rather than the file name.

Not $ dev_appserver helloapp.py
But $ dev_appserver hello/

For example:

Johns-Mac:hello john$ dev_appserver.py helloworld.py
Traceback (most recent call last):
  File "/usr/local/bin/dev_appserver.py", line 82, in <module>
    _run_file(__file__, globals())
...
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/yaml_listener.py", line 212, in _GenerateEventParameters
    raise yaml_errors.EventListenerYAMLError(e)
google.appengine.api.yaml_errors.EventListenerYAMLError: mapping values are not allowed here
  in "helloworld.py", line 3, column 39

Versus

Johns-Mac:hello john$ cd ..
Johns-Mac:fbm john$ dev_appserver.py hello/
INFO     2014-09-15 11:44:27,828 api_server.py:171] Starting API server at: http://localhost:61049
INFO     2014-09-15 11:44:27,831 dispatcher.py:183] Starting module "default" running at: http://localhost:8080