Back to home

TripleO service deployment steps

TripleO does a lot of things in the whole deployment process, from setting up the appropriate networks, to provisioning the baremetal hosts. However, there is a significant part of the deployment in which services are configured. This part of the deployment is done in 5 steps. What happens in these steps has traditionally been the following:

1) Load Balancer configuration

2) Core Services (Database/Rabbit/NTP/etc.)

3) Early Openstack Service setup (Ringbuilder, etc.)

4) General OpenStack Services

5) Service activation (Pacemaker) & Service post-configuration (e.g. nova host discovery)

This has tended to be done by Puppet, however, with the arrival of containers to the deployment, and the need to provide more options to deploy the services, there are now several things happening in between these steps. These would be the overall steps nowadays:

• Host prep deployment (ansible tasks)

• Containers config files generated per hiera settings.

• Load Balancer configuration baremetal

  • external deploy step tasks (ansible tasks)

  • deploy step tasks (ansible tasks)

  • step 1 baremetal (puppet)

  • step 1 containers

• Core Services (Database/Rabbit/NTP/etc.)

  • external deploy step tasks (ansible tasks)

  • deploy step tasks (ansible tasks)

  • step 2 baremetal (puppet)

  • step 2 containers

• Early Openstack Service setup (Ringbuilder, etc.)

  • external deploy step tasks (ansible tasks)

  • deploy step tasks (ansible tasks)

  • step 3 baremetal (puppet)

  • step 3 containers

• General OpenStack Services

  • external deploy step tasks (ansible tasks)

  • deploy step tasks (ansible tasks)

  • step 4 baremetal (puppet)

  • step 4 containers

  • Keystone containers post initialization (tenant,service,endpoint creation)

• Service activation (Pacemaker)

  • external deploy step tasks (ansible tasks)

  • deploy step tasks (ansible tasks)

  • step 5 baremetal (puppet)

  • step 5 containers

It’s useful to have the overall picture. Next, I’ll try to explain the details that are relevant to understanding what happens in each step and before them.

• Host prep deployment: This is seen as host_prep_tasks in the deployment service templates. These are ansible tasks that run before the configuration steps start. Typically because you want these steps to happen before the pacemaker configuration. Here you would put actions such as wiping out your disk, or migrating log files.

• Container config files: While traditionally, the configuration was done via puppet in each step. This changed when containers came around. Nowadays, the configuration files for containerized services are generated all in one go, before the steps happen. Subsequently, containers are started in the step that they would usually be started by puppet.

• External deploy step tasks: These are tasks that are ran from the node that’s doing the deployment (typically the undercloud). These are powered by Ansible.

• Deploy step tasks: These are tasks that are ran on every overcloud node of a certain role. These are also powered by Ansible.

• Baremetal step: This will typically be the execution of the step_config statement in the service templates. Note that this will only happen for a service if it’s configured to run on baremetal.

• Container step: This will initiate the containers that are configured to run on a certain step.

With these brief explanations, I hope you have a better notion of what’s going on in the deployment steps. If you want more in-depth knowledge about these steps, I’m also writing a services of blog posts that describe the service templates; which include way more detail. The series starts with a blog post describing the minimal things you need for your service template

tags: tripleo - openstack

Back to home