rabbitmq_parameter module json argument - json

Question

I'm trying to use the rabbitmq_parameter ansible module to set a federation upstream set, while dynamically generating the set, with something like this:
- name: Set federation upstream set
rabbitmq_parameter:
component: federation-upstream-set
name: my-upstreams
vhost: my-vhost
value: "{{ my_upstream_set }}"
The variable my_upstream_set is defined in a separate host variable file, like so:
my_upstream_set: [{"upstream": "upstream1"}, {"upstream": "upstream2"}]
However, no matter how I generate the value argument, which must be json, (with or without quotes, with simple or double quotes, yaml or json formatted), I can't get this to work. I get either the task failing with "stderr: Error: JSON decoding error", or the following error:
failed: [myhost] => {"failed": true, "parsed": false}
invalid output was: Traceback (most recent call last):
File "<stdin>", line 1498, in <module>
File "<stdin>", line 142, in main
File "<stdin>", line 104, in set
File "<stdin>", line 88, in _exec
File "<stdin>", line 1351, in run_command
File "/usr/lib/python2.7/posixpath.py", line 261, in expanduser
if not path.startswith('~'):
AttributeError: 'list' object has no attribute 'startswith'
debug3: mux_client_read_packet: read header failed: Broken pipe
debug2: Received exit status from master 1
I've tried running the task with a hardcoded value (so, directly in the task file) and it works as expected, but I have no way of integrating variables into that. Any idea what I might be doing wrong here? Thanks!

Answer 1

my_upstream_set should be a JSON (string) in your case it is a list.