Operating Kolla

Operating Kolla


Kolla’s strategy for upgrades is to never make a mess and to follow consistent patterns during deployment such that upgrades from one environment to the next are simple to automate.

Kolla implements a one command operation for upgrading an existing deployment consisting of a set of containers and configuration data to a new deployment.

Kolla uses the x.y.z semver nomenclature for naming versions. Kolla’s Liberty version is 1.0.0 and the Mitaka version is 2.0.0. The Kolla community commits to release z-stream updates every 45 days that resolve defects in the stable version in use and publish those images to the Docker Hub registry. To prevent confusion, the Kolla community recommends using an alpha identifier x.y.z.a where a represents any customization done on the part of the operator. For example, if an operator intends to modify one of the Docker files or the repos from the originals and build custom images for the Liberty version, the operator should start with version and increase alpha for each release. Alpha tag usage is at discretion of the operator. The alpha identifier could be a number as recommended or a string of the operator’s choosing.

If the alpha identifier is not used, Kolla will deploy or upgrade using the version number information contained in the release. To customize the version number uncomment openstack_version in globals.yml and specify the version number desired.

For example, to deploy a custom built Liberty version built with the kolla-build --tag operation, change globals.yml:


Then run the command to deploy:

kolla-ansible deploy

If using Liberty and a custom alpha number of 0, and upgrading to 1, change globals.yml:


Then run the command to upgrade:

kolla-ansible upgrade


Varying degrees of success have been reported with upgrading the libvirt container with a running virtual machine in it. The libvirt upgrade still needs a bit more validation, but the Kolla community feels confident this mechanism can be used with the correct Docker graph driver.


The Kolla community recommends the btrfs or aufs graph drivers for storing data as sometimes the LVM graph driver loses track of its reference counting and results in an unremovable container.


Because of system technical limitations, upgrade of a libvirt container when using software emulation (virt_type = qemu in nova.conf), does not work at all. This is acceptable because KVM is the recommended virtualization driver to use with Nova.

Tips and Tricks

Kolla ships with several utilities intended to facilitate ease of operation.

tools/cleanup-containers is used to remove deployed containers from the system. This can be useful when you want to do a new clean deployment. It will preserve the registry and the locally built images in the registry, but will remove all running Kolla containers from the local Docker daemon. It also removes the named volumes.

tools/cleanup-host is used to remove remnants of network changes triggered on the Docker host when the neutron-agents containers are launched. This can be useful when you want to do a new clean deployment, particularly one changing the network topology.

tools/cleanup-images --all is used to remove all Docker images built by Kolla from the local Docker cache.

kolla-ansible -i INVENTORY deploy is used to deploy and start all Kolla containers..

kolla-ansible -i INVENTORY destroy is used to clean up containers and volumes in the cluster.

kolla-ansible -i INVENTORY mariadb_recovery is used to recover a completely stopped mariadb cluster.

kolla-ansible -i INVENTORY prechecks is used to check if all requirements are meet before deploy for each of the OpenStack services.

kolla-ansible -i INVENTORY post-deploy is used to do post deploy on deploy node to get the admin openrc file.

kolla-ansible -i INVENTORY pull is used to pull all images for containers.

kolla-ansible -i INVENTORY reconfigure is used to reconfigure OpenStack service.

kolla-ansible -i INVENTORY upgrade is used to upgrades existing OpenStack Environment.

kolla-ansible -i INVENTORY check is used to do post-deployment smoke tests.


In order to do smoke tests, requires kolla_enable_sanity_checks=yes.

kolla-mergepwd --old OLD_PASSWDS --new NEW_PASSWDS --final FINAL_PASSWDS is used to merge passwords from old installation with newly generated passwords during upgrade of Kolla release. The workflow is:

  • Save old passwords from /etc/kolla/passwords.yml into passwords.yml.old
  • Generate new passwords via kolla-genpwd as passwords.yml.new
  • Merge passwords.yml.old and passwords.yml.new into /etc/kolla/passwords.yml

For example:

mv /etc/kolla/passwords.yml passwords.yml.old
cp kolla-ansible/etc/kolla/passwords.yml passwords.yml.new
kolla-genpwd -p passwords.yml.new
kolla-mergepwd --old passwords.yml.old --new passwords.yml.new --final /etc/kolla/passwords.yml
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