can't send numbers in std.http header since requests upgrade to 2.11.0

[Michal Gershenzon]

In a new devstack requests 2.11.0 was installed
In version 2.10.0 of requests they accepted integers as header value and from 2.11.0 they stopped.
The info came from here: https://github.com/kennethreitz/requests/issues/3477#issuecomment-238381586

workflow works with 2.10.0, but not with 2.11.0:
---
version: '2.0'

sync_http:
  type: direct
  input:
    - metadata: abcd1234
    - num: 7

  tasks:
    send_mistral_http:
      action: std.http
      input:
        url: <% "http://requestb.in/x5477xx5?metadata=" + $.metadata %>
        headers:
          num: <% $.num %>

exception from log:
http://paste.openstack.org/show/564344/

This might affect other things too.

A workaround for devstack:
sudo pip uninstall requests
sudo pip install -I requests==2.10.0

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/365037

[Renato Recio (recio862)]

Not sure if casting is the solution here. It may be better to enforce the end user to specify string in yaml (using quotes) instead of assuming the api will handle it.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/365037
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=cbc0a9928a973345a9084b2cc05880a79b5425f0
Submitter: Jenkins
Branch: master

commit cbc0a9928a973345a9084b2cc05880a79b5425f0
Author: Renato Recio <email address hidden>
Date: Fri Sep 2 10:50:31 2016 -0500

    cast to str for allowable types

    Change-Id: Ie2680328ff352718ab266f6533e27eee532d68bb
    Closes-Bug: 1617762

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/mistral 3.0.0.0rc1 release candidate.