kolla-kubernetes/doc/source/multi-node.rst

Kolla Kubernetes Multi-Node Guide

This guide documents how to deploy kolla-kubernetes within a multi-node Kubernetes cluster. It will guide you through all of the dependencies required to deploy Horizon, the Openstack Admin Web Interface. It works for kubernetes clusters supporting various storage providers including GCE compute disks, AWS EBS, Ceph RBD, and even local host mounts if you are developing multi-node on an all-in-one system.

This is an advanced guide. Before attempting to deploy on a multi-node cluster, please follow the quickstart and ensure that you have successfully deployed kolla-kubernetes on a single host using the kubernetes-all-in-one. This multi-node guide requires quite a few system dependencies to be addressed by the quickstart.

Following this guide will result in a minimal kolla-kubernetes multi-node deployment consisting of:

• 1 mariadb instance
• 1 memcached instance
• 3 keystone instances
• 3 horizon instances

The end result will be a working Horizon admin interface and its dependencies deployed with all of the self-healing and auto-wiring benefits that a kubernetes cluster has to offer. You should be able to destroy kubernetes nodes at will, and the system should self-heal and maintain state as pods migrate from destroyed nodes to new nodes. You may also destroy all kubernetes nodes, then bring some back, and the system should again self-heal. Because we are using network volumes, mariadb state is maintained since its network volume will follow the pod as it is rescheduled from one node to the next.

Pre-Requisites

Follow the quickstart, configure your system, and do a "Development Install" of kolla and kolla-kubernetes. This is absolutely required.

Configure Kolla

For multi-node deployments, a docker registry is required since the kubernetes nodes will not be able to find the kolla images that your development machine has built. Thus, we must configure kolla to name the images correctly, so that we may easily push the images to the right docker registry.

Add your docker registry settings in the kolla configuration file `./etc/kolla/globals.yaml`.

# Edit kolla config ./etc/kolla/globals.yml
docker_registry: "<registry_url>"  # e.g. "gcr.io"
docker_namespace: "<registry_namespace>  # e.g. "annular-reef-123"

Generate the kolla configurations, build the kolla images, and push the kolla images to your docker registry.

# Generate the kolla configurations
pushd kolla
sudo ./tools/generate_passwords.py  # (Optional: will overwrite)
sudo ./tools/kolla-ansible genconfig
popd

Build Kolla Images and Push to Docker Registry

# Set env variables to make subsequent commands cut-and-pasteable
export DOCKER_REGISTRY="<registry_url>"
export DOCKER_NAMESPACE="<registry_namespace>"
export DOCKER_TAG="3.0.0"
export KOLLA_CONTAINERS="mariadb memcached kolla-toolbox keystone horizon"

# Build the kolla containers
kolla-build $KOLLA_CONTAINERS --registry $DOCKER_REGISTRY --namespace $DOCKER_NAMESPACE

# Authenticate with your docker registry
#   This may not be necessary if you are using a cloud provider
docker login

# Push the newly-built kolla containers to your docker registry
#   For GKE, change the command below to be "gcloud docker push"
for i in $KOLLA_CONTAINERS; do
  docker push "$DOCKER_REGISTRY/$DOCKER_NAMESPACE/centos-binary-$i:$DOCKER_TAG"
done

Configure Kolla-Kubernetes

Modify the kolla-kubernetes configuration file `./etc/kolla-kubernetes/kolla-kubernetes.yml` to set the number of instance replicas. In addition, set the storage_provider settings to match your environment.

# Edit kolla-kubernetes config ./etc/kolla-kubernetes/kolla-kubernetes.yml

########################
# Kubernetes Cluster
########################
keystone_replicas: "3"
horizon_replicas: "3"

########################
# Persistent Storage
########################
storage_provider: "host"  # host, ceph, gce, aws
storage_ceph:
  keyring: /etc/ceph/ceph.client.admin.keyring
  monitors:
  - x.x.x.x
  - y.y.y.y
  pool: rbd
  secretName: pkt-ceph-secret
  ssh_user: root
  user: admin

Known Issues

#1. On GCE, the mariadb pod is unable to mount the network drive that was prior mounted by the mariadb-bootstrap job, until the mariadb-bootstrap job is deleted. The same should also occur for AWS and Ceph.

#2. When running Kubernetes, Ceph RBD volumes will not auto-unlock when Kubernetes nodes disappear, causing problems when a pod migrates to a new node and cannot mount the required volume. This was supposed to have been fixed in Kubernetes 1.3, but we have been unable to verify it working. Details are found in the in this kubernetes pull request.

Create all Kolla-Kubernetes Resources

Execute the following commands to create the kolla-kubernetes multi-node cluster. There are two unique perspectives, that of an operator and that of a workflow engine. The workflow engine drives the same CLI subcommands that are accessible to operators.

However, since the workflow engine does not yet exist, the shortcut workflow commands as defined in the quickstart are still supported.

All of the commands below are cut and pasteable.

Operator Create Resources

kolla-kubernetes bootstrap ceph  # adds ceph secret, no-op for storage_provider!=ceph
kolla-kubernetes bootstrap mariadb
sleep 30  # wait for mariadb bootstrap to finish
kolla-kubernetes resource delete mariadb bootstrap  # workaround known issue #1
kolla-kubernetes run mariadb
kolla-kubernetes run memcached
sleep 30  # wait for mariadb and memcached to start up
kolla-kubernetes bootstrap keystone
sleep 30  # wait for keystone to bootstrap in mariadb
kolla-kubernetes run keystone
sleep 30  # wait for keystone to start up
kolla-kubernetes run horizon

Workflow Engine Create Resources

A future Ansible Workflow Engine would individually call the discrete bits of logic.

kolla-kubernetes resource create mariadb disk
kolla-kubernetes resource create mariadb pv
kolla-kubernetes resource create mariadb pvc
kolla-kubernetes resource create mariadb svc
kolla-kubernetes resource create mariadb configmap
kolla-kubernetes resource create mariadb bootstrap
sleep 30  # wait for mariadb bootstrap to finish
kolla-kubernetes resource delete mariadb bootstrap  # workaround known issue #1
kolla-kubernetes resource create mariadb pod
kolla-kubernetes resource create memcached svc
kolla-kubernetes resource create memcached configmap
kolla-kubernetes resource create memcached pod
kolla-kubernetes resource create keystone svc
kolla-kubernetes resource create keystone configmap
sleep 30  # wait for mariadb and memcached to start up
kolla-kubernetes resource create keystone bootstrap
sleep 30  # wait for keystone to bootstrap in mariadb
kolla-kubernetes resource create keystone pod
kolla-kubernetes resource create horizon svc
kolla-kubernetes resource create horizon configmap
sleep 30  # wait for keystone to start up
kolla-kubernetes resource create horizon pod

Check Status of all Kolla-Kubernetes Resources

Checking status is the same whether for operators or workflow engine.

kolla-kubernetes resource status mariadb disk
kolla-kubernetes resource status mariadb pv
kolla-kubernetes resource status mariadb pvc
kolla-kubernetes resource status mariadb svc
kolla-kubernetes resource status mariadb configmap
kolla-kubernetes resource status mariadb bootstrap
kolla-kubernetes resource status mariadb pod
kolla-kubernetes resource status memcached svc
kolla-kubernetes resource status memcached configmap
kolla-kubernetes resource status memcached pod
kolla-kubernetes resource status keystone svc
kolla-kubernetes resource status keystone configmap
kolla-kubernetes resource status keystone bootstrap
kolla-kubernetes resource status keystone pod
kolla-kubernetes resource status horizon svc
kolla-kubernetes resource status horizon configmap
kolla-kubernetes resource status horizon pod

Delete all Kolla-Kubernetes Resources

Deleting all resources is exactly executing the creation steps in reverse.

Operator Delete Resources

kolla-kubernetes kill horizon
kolla-kubernetes kill keystone
kolla-kubernetes kill memcached
kolla-kubernetes kill mariadb
kolla-kubernetes kill ceph

Workflow Engine Delete Resources

kolla-kubernetes resource delete horizon pod
kolla-kubernetes resource delete horizon configmap
kolla-kubernetes resource delete horizon svc
kolla-kubernetes resource delete keystone pod
kolla-kubernetes resource delete keystone bootstrap
kolla-kubernetes resource delete keystone configmap
kolla-kubernetes resource delete keystone svc
kolla-kubernetes resource delete memcached pod
kolla-kubernetes resource delete memcached configmap
kolla-kubernetes resource delete memcached svc
kolla-kubernetes resource delete mariadb pod
kolla-kubernetes resource delete mariadb bootstrap
kolla-kubernetes resource delete mariadb configmap
kolla-kubernetes resource delete mariadb svc
kolla-kubernetes resource delete mariadb pvc
kolla-kubernetes resource delete mariadb pv
kolla-kubernetes resource delete mariadb disk