Solum/configurations

Solum supports following deployment configurations:

- Deploying application containers (DU) using nova-docker (deploy-direct-container configuration)

- Deploying application containers (DU) on VM (deploy-container-on-vm configuration)

Workings of each of these configurations is described below.

Deploying DU using nova-docker

This configuration is characterized by three things. First nova needs to be configured with the nova-docker compute driver. This is done by adding following line to /etc/nova/nova.conf: compute_driver = novadocker.virt.docker.driver.DockerDriver

Second, the DU images need to be stored in Glance for the nova-docker driver to deploy it. In Solum there is a configuration parameter that you can set that will cause the DU images to be stored in Glance. This is done by setting the image_storage property in /etc/solum/solum.conf to 'glance'.

Third, internally Solum performs the deployment using the 'basic' heat template, which is available at: https://github.com/openstack/solum/blob/master/etc/solum/templates/basic.yaml

Deploying DU on VM

At a high-level this configuration works by first spinning up a VM and then running the DU image on it. Solum achieves this by:

- storing the DU image in Swift
- generating a Swift tempURL for the DU
- passing instructions as part of the  cloud-init section for the Heat template for deploying a VM to download the DU image from Swift, load it, and run it.

In order to make this work, following settings are required.

In nova's /etc/nova/nova.conf, set the compute_driver value to 'libvirt.LibvirtDriver'.

Restart nova services through their respective screen sessions. Nova services have names that start with 'n-'. You can restart these nova services by shutting them down (Cntrl-C) and starting them (load the previous command from the screen session and execute it).

In solum's /etc/solum/solum.conf set the following configuration variables:

- image_storage value to 'swift'
- image_format value to 'vm'
- add a variable 'image' and set its value to the id of the VM image (from Glance) that you want to use to spin up the VM
- add a variable 'flavor' and set its value to the flavor of the VM

Restart solum services through their respective screen sessions. Solum services have names that start with 'solum-'

Internally Solum performs the deployment using the 'coreos' heat template for deployment, which is available at: https://github.com/openstack/solum/blob/master/etc/solum/templates/coreos.yaml