Operating Kolla

updated: 2020-09-14 11:39

Operating Kolla

Versioning

Kolla uses the x.y.z semver nomenclature for naming versions. Kolla’s initial Pike release was 5.0.0 and the initial Queens release is 6.0.0. 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 Pike version, the operator should start with version 5.0.0.0 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.

To customize the version number uncomment openstack_release in globals.yml and specify the version number desired. If openstack_release is not specified, Kolla will deploy or upgrade using the version number information contained in the kolla-ansible package.

Upgrade procedure

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.

Limitations and Recommendations

Note

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.

Note

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.

Note

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.

Note

Please note that when the use_preconfigured_databases flag is set to "yes", you need to have the log_bin_trust_function_creators set to 1 by your database administrator before performing the upgrade.

Preparation

While there may be some cases where it is possible to upgrade by skipping this step (i.e. by upgrading only the openstack_release version) - generally, when looking at a more comprehensive upgrade, the kolla-ansible package itself should be upgraded first. This will include reviewing some of the configuration and inventory files. On the operator/master node, a backup of the /etc/kolla directory may be desirable.

If upgrading from 5.0.0 to 6.0.0, upgrade the kolla-ansible package:

pip install --upgrade kolla-ansible==6.0.0

If this is a minor upgrade, and you do not wish to upgrade kolla-ansible itself, you may skip this step.

The inventory file for the deployment should be updated, as the newer sample inventory files may have updated layout or other relevant changes. Use the newer 6.0.0 one as a starting template, and merge your existing inventory layout into a copy of the one from here:

/usr/share/kolla-ansible/ansible/inventory/

In addition the 6.0.0 sample configuration files should be taken from:

# CentOS
/usr/share/kolla-ansible/etc_examples/kolla

# Ubuntu
/usr/local/share/kolla-ansible/etc_examples/kolla

At this stage, files that are still at the 5.0.0 version - which need manual updating are:

  • /etc/kolla/globals.yml
  • /etc/kolla/passwords.yml

For globals.yml relevant changes should be merged into a copy of the new template, and then replace the file in /etc/kolla with the updated version. For passwords.yml, see the kolla-mergepwd instructions in Tips and Tricks.

For the kolla docker images, the openstack_release is updated to 6.0.0:

openstack_release: 6.0.0

Once the kolla release, the inventory file, and the relevant configuration files have been updated in this way, the operator may first want to ‘pull’ down the images to stage the 6.0.0 versions. This can be done safely ahead of time, and does not impact the existing services. (optional)

Run the command to pull the 6.0.0 images for staging:

kolla-ansible pull

At a convenient time, the upgrade can now be run (it will complete more quickly if the images have been staged ahead of time).

Perform the Upgrade

To perform the upgrade:

kolla-ansible upgrade

After this command is complete the containers will have been recreated from the new images.

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.

kolla-ansible -i INVENTORY stop is used to stop running containers.

Note

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:

  1. Save old passwords from /etc/kolla/passwords.yml into passwords.yml.old.
  2. Generate new passwords via kolla-genpwd as passwords.yml.new.
  3. 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
updated: 2020-09-14 11:39
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