Ansible URI module issue with multiple data objects

ansible_uri.yaml

# This works
- name: "Set the Couchbase cluster security settings"
  shell: "curl -v -X POST http://{{ couchbase_host }}:{{ couchbase_cluster_port }}/settings/web \
          -d port={{ couchbase_cluster_port }} \
          -d username={{ couchbase_cluster_username }} \
          -d password={{ couchbase_cluster_password }}"

# This does not:
- name: "Set the Couchbase cluster security settings"
  uri:
    url: http://{{ couchbase_host }}:{{ couchbase_cluster_port }}/settings/web
    method: POST
    user: "{{ couchbase_cluster_username }}"
    password: "{{ couchbase_cluster_password }}"
    body:
      port={{ couchbase_cluster_port }}
      username={{ couchbase_cluster_username }}
      password={{ couchbase_cluster_password }}
    force_basic_auth: no
    status_code: 200
    body_format: raw
  
  # and returns:
  {
    "cache_control": "no-cache",
    "changed": false,
    "content": "[\"All parameters must be given\"]",
    "content_length": "32",
    "content_type": "application/json",
    "date": "Wed, 21 Sep 2016 17:08:49 GMT",
    "failed": true,
    "json": ["All parameters must be given"],
    "msg": "Status code was not [200]: HTTP Error 400: Bad Request",
    "pragma": "no-cache",
    "redirected": false,
    "server": "Couchbase Server",
    "status": 400,
    "url": "http://127.0.0.1:8091/settings/web"
}

# Also tried with:
    body_format: json
    HEADER_Content-Type: application/json
# That does not work either.


# This works
# POST /settings/web
# This command can be run only _ONCE_ against each Couchbase node, if you try it a second time you will get a HTTP 401 Unauthorized error
- name: "Set the Couchbase cluster security settings"
  uri:
    url: http://{{ couchbase_host }}:{{ couchbase_cluster_port }}/settings/web
    method: POST
    user: "{{ couchbase_cluster_username }}"
    password: "{{ couchbase_cluster_password }}"
    body: username={{ couchbase_cluster_username }}&password={{ couchbase_cluster_password }}&port={{ couchbase_cluster_port }}
    force_basic_auth: no
    status_code: 200
    body_format: raw
  when: couchbase_service_status.state == 'started'
  register: hostname_result