Comment 0 for bug 1752308

Trying to enable the dashboard module in ceph-mrg according to this guide https://blog.widodh.nl/2017/06/using-the-new-dashboard-in-ceph-mgr/ I'm seeing an error in the ceph-mgr log during startup:

2018-02-28 11:27:54.507314 7fb635382680 0 ceph version 12.2.2 (cf0baeeeeba3b47f9427c6c97e2144b094b7e5ba) luminous (stable), process (unknown), pid 27970
2018-02-28 11:27:54.508791 7fb635382680 0 pidfile_write: ignore empty --pid-file
2018-02-28 11:27:54.514032 7fb635382680 1 mgr send_beacon standby
2018-02-28 11:27:54.526143 7fb62c6b4700 1 mgr init Loading python module 'dashboard'
2018-02-28 11:27:54.577279 7fb62c6b4700 -1 mgr load Module not found: 'dashboard'
2018-02-28 11:27:54.577289 7fb62c6b4700 -1 mgr load Traceback (most recent call last):
  File "/usr/lib/x86_64-linux-gnu/ceph/mgr/dashboard/__init__.py", line 2, in <module>
    from module import * # NOQA
  File "/usr/lib/x86_64-linux-gnu/ceph/mgr/dashboard/module.py", line 28, in <module>
    import jinja2
ImportError: No module named jinja2

Expected result (seen after installing python-jinja2 pkg):

2018-02-28 11:38:24.950585 7f8302522680 0 ceph version 12.2.2 (cf0baeeeeba3b47f9427c6c97e2144b094b7e5ba) luminous (stable), process (unknown), pid 31137
2018-02-28 11:38:24.952035 7f8302522680 0 pidfile_write: ignore empty --pid-file
2018-02-28 11:38:24.956888 7f8302522680 1 mgr send_beacon standby
2018-02-28 11:38:24.969668 7f82f9854700 1 mgr init Loading python module 'dashboard'
2018-02-28 11:38:25.066943 7f82f9854700 1 mgr init Loading python module 'restful'
2018-02-28 11:38:25.167533 7f82f9854700 1 mgr init Loading python module 'status'
2018-02-28 11:38:25.185504 7f82f9854700 1 mgr load Constructed class from module: dashboard

So that package should be added as dependency to ceph-mgr.