3.4 About the OpenStack Kolla User

Oracle OpenStack for Oracle Linux uses Ansible to deploy the OpenStack Docker containers to the target nodes. Ansible requires an SSH login on the target nodes, and Oracle OpenStack for Oracle Linux uses the kolla user and SSH keys for this purpose. The configuration of the kolla user happens automatically, as follows.

When you prepare target nodes by installing either the openstack-kolla-preinstall package or the openstack-kollacli package, the openstack-kolla-user package is also installed. This package prepares the kolla user and performs the following operations on the node:

Create the kolla group.
The kolla group is for the users that run the kollacli command.
Create the docker group.
The docker group enables non-root users to run docker commands.
Create the kolla user.
The user is created as a system user with the home directory set to /usr/share/kolla. The user is added to the kolla and docker groups, with the kolla group as the primary group. No private group is created for the user.
Set up sudoers for the kolla user.
Configuration is added either to the /etc/sudoers.d/kolla or the /etc/sudoers configuration file.
The configuration enables the kolla user to run commands, such as ansible and ansible-playbook, as root without prompting for a password.
Set up SSH for the kolla user.
The SSH configuration directory (.ssh) is created in the kolla user's home directory, the authorized_keys file is created in the .ssh directory.

When you install the openstack-kollacli package on the master node, SSH public and private keys are created for the kolla user on the master node.

When you run the kollacli host setup command, as described in Section 4.1, “Setting up Target Nodes”, the public key is copied from the master node to the kolla user's authorized_keys file on the target nodes.