exec.bash

# on minion
root@minion# cat /etc/salt/minion
grains:
  role: qa1
  # ...
root@minion# salt-call grains.get role
local:
    qa1
root@minion# salt-call state.apply
local:
    Data failed to compile:
----------
    Pillar failed to render with the following messages:
----------
    Rendering SLS 'servers.qa' failed. Please see master log for details.
root@minion# salt-call saltutil.sync_grains
local:
root@minion# salt-call state.apply
local:
    Data failed to compile:
----------
    Pillar failed to render with the following messages:
----------
    Rendering SLS 'servers.qa' failed. Please see master log for details.


# on master
root@master# salt -G 'role:qa1' grains.get role
i-010...:
qa1

master.log

2017-01-06 14:37:22,558 [salt.pillar      ][CRITICAL][10803] Rendering SLS 'servers.qa' failed, render error:
Jinja error: unsupported operand type(s) for +: 'NoneType' and 'str'
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/salt/utils/templates.py", line 379, in render_jinja_tmpl
    output = template.render(**decoded_context)
  File "/usr/lib/python2.7/dist-packages/jinja2/environment.py", line 989, in render
    return self.environment.handle_exception(exc_info, True)
  File "/usr/lib/python2.7/dist-packages/jinja2/environment.py", line 754, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "<template>", line 8, in top-level template code
TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'

; line 8

---
[...]
postgres:
  host: {{ grains.get('role') + 'database.example.com' }}    <======================
[...]
---

qa.sls

# pillar/servers/qa.sls
postgres:
host: {{ grains.get('role') + 'database.example.com' }}

top.sls

# pillar/top.sls
base:
  # ...
  'role:qa*':
    - match: grain
- servers.qa