Coding the playbooks and roles
In this section, we will now create the playbook and role that will allow you to migrate an instance to a specific compute node using the traditional openstack server migrate command. Unlike the other tasks we have created thus far, there is really only one way to handle this task. We will take the steps outlined two sections earlier, automate them so that you only need to supply a few variable values, and then execute only one command.
This chapter started off talking about instance migration and how there are two options within Nova to handle this: traditional migration and live migration. The traditional migration process is really a one-step process, but in order to properly automate this task, we will need to add a few more steps to the process. The brief outline of the tasks we will have to create are:
List the compute nodes.
Collect premigration instance details.
Disable all compute nodes except for the one we want the instance to migrate to.
Migrate the...
