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https://github.com/mirantis/ceph-cm-ansible


https://github.com/mirantis/ceph-cm-ansible

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README 

        
Overview

========



This project is meant to store ansible roles for managing the nodes in the ceph

testing labs.



Inventory

=========



As this repo only contains roles, it does not define the ansible inventory or

any associated group_vars or host_vars.  However, it does depend on these

things existing in a separate repository or otherwise accesible by these roles

when they are used. Any vars a role needs should be added to its

``defaults/main.yml`` file to document what must be defined per node or group

in your inventory.



This separation is important because we have multiple labs we manage with these

same roles and each lab has different configuration needs. We call these our

``secrets`` or ``*-secrets`` repos throughout the rest of the documention and

in the roles.



Besides the inventory, ``secrets`` repos also may contain certain secret or

encrypted files that we can not include in ceph-cm-ansible for various reasons.



The directory structure for one of our ``secrets`` repos is::



    ├── ansible

        ├── inventory

        │   ├── group_vars

        │   │   ├── all.yml

        │   │   ├── cobbler.yml

        │   │   ├── testnodes.yml

        │   │   ├── teuthology.yml

        │   │   └── typica.yml

        │   └── sepia

        └── secrets

            └── entitlements.yml



Refer to Step 2 below for instructions on how to setup a ``secrets`` repo for

use by ceph-cm-ansible. If set up this way, -i is not necessary for

ansible-playbook to find the repo. However, you can choose your own setup and

point to the ``secrets`` repo with -i if you prefer.



**NOTE:** Some playbooks require specific groups to be defined in your

inventory. Please refer to ``hosts`` in the playbook you want to use to ensure

you've got the proper groups defined.



Where should I put variables?

-----------------------------



All variables should be defined in ``defaults/main.yml`` for the role they're

primarily used in.  If the variable you're adding can be used in multiple roles

define it in ``defaults/main.yml`` for both roles. If the variable can contain

a reasonable default value that should work for all possible labs then define

that value in ``defaults/main.yml`` as well.  If not, you should still default

the variable to something, but make the tasks that use the variable either fail

gracefully without that var or prompt the user to define it if it's mandatory.



If the variable is something that might need to be defined with a value

specific to the lab in use, then it'll need to be added to your ``secrets``

repo as well. Variables in ``group_vars/all.yml`` will apply to all nodes

unless a group_var file exists that is more specific for that node.  For

example, if you define the var ``foo: bar`` in ``all.yml`` and the node you're

running ansible against exists in the ``testnodes`` group and there is a

``group_vars/testnodes.yml`` file defined with ``foo: baz`` included in it then

the role using the variable will use the value defined in ``testnodes.yml``.

The playbook you're using knows which group_var file to use because of the

``hosts`` value defined for it.



Setting up a local dev environment

==================================



We assume that your SSH key is present and active for passwordless access to

the "ubuntu" shell user on the hosts that ansible will manage.



Step 1: Install ansible

-----------------------



You can use pip::



  pip install ansible



or use the OS package manager::

  

  yum install ansible



Step 2: Set up secrets repository

---------------------------------



Clone the secrets repository and symlink the ``hosts`` and ``secrets``

directories into place::



  cd $HOME/dev/

  git clone git@..../ceph-ansible-secrets.git



  sudo mv /etc/ansible/hosts /etc/ansible/hosts.default



  sudo ln -s /path/to/ceph-ansible-secrets/ansible/inventory /etc/ansible/hosts

  sudo ln -s /path/to/ceph-ansible-secrets/ansible/secrets /etc/ansible/secrets



Step 3: Clone the main Ceph ansible repo

----------------------------------------



Clone the main Ceph ansible repository::



  git clone git@..../ceph-cm-ansible.git

  cd ceph-cm-ansible

  

Step 4 (Optional) Modify ``hosts`` files

----------------------------------------

If you have any new hosts on which you'd like to run ansible, or if you're

using separate testing VMs, edit the files in ``/etc/ansible/hosts`` to add

your new (or testing) hosts::



  vi /etc/ansible/hosts/



If you don't need to test on any new hosts, you can skip this step and just use

``/etc/ansible/hosts`` as-is.



Step 5: Run ``ansible-playbook``

--------------------------------



You can now run ``ansible-playbook``::



  vi myplaybook.yml

  ansible-playbook myplaybook.yml -vv --check --diff



This will print a lot of debugging output to your console.



Adding a new host to ansible

============================



Ansible runs using the "cm" shell account.



Let's say you've created a new VM host using downburst. At this point you

should have a new VM with the "ubuntu" UID present. The problem is that Ansible

uses the "cm" user. In order to get that UID set up:



1. Add your host to the inventory. Look in your lab's ``secrets`` repository,

   in the ``ansible/inventory/`` directory, and add your new node.



2. Run the ``cephlab.yml`` playbook, limited to your new host "mynewhost"::



    ansible-playbook -vv --limit mynewhost cephlab.yml