Nodepool - OpenStack

Setup

Before starting on this, you need to download your openrc configuration from your OpenStack cloud. Put it on your server in the staging user’s home directory. It should be called <username>-openrc.sh. Once that is done, create a new keypair that will be installed when instantiating the servers:

cd ~
source <username>-openrc.sh  # this may prompt for password - enter it
openstack keypair create --public-key nodepool_rsa.pub nodepool

We’ll use the private key later when configuring Zuul. In the same session, configure nodepool to talk to your cloud:

umask 0066
sudo mkdir -p ~nodepool/.config/openstack
cat > clouds.yaml <<EOF
clouds:
  mycloud:
    auth:
      username: $OS_USERNAME
      password: $OS_PASSWORD
      project_name: ${OS_PROJECT_NAME:-$OS_TENANT_NAME}
      auth_url: $OS_AUTH_URL
    region_name: $OS_REGION_NAME
EOF
sudo mv clouds.yaml ~nodepool/.config/openstack/
sudo chown -R nodepool.nodepool ~nodepool/.config
umask 0002

Once you’ve written out the file, double check all the required fields have been filled out.

Configuration

You’ll need the following information in order to create the Nodepool configuration file:

• cloud name / region name - from clouds.yaml

• flavor-name

• image-name - from your cloud

sudo bash -c "cat >/etc/nodepool/nodepool.yaml <<EOF
zookeeper-servers:
  - host: localhost
    port: 2181

providers:
  - name: myprovider # this is a nodepool identifier for this cloud provider (cloud+region combo)
    region-name: regionOne  # this needs to match the region name in clouds.yaml but is only needed if there is more than one region
    cloud: mycloud  # This needs to match the name in clouds.yaml
    cloud-images:
      - name: centos-7   # Defines a cloud-image for nodepool
        image-name: CentOS-7-x86_64-GenericCloud-1706  # name of image from cloud
        username: centos  # The user Zuul should log in as
    pools:
      - name: main
        max-servers: 4  # nodepool will never create more than this many servers
        labels:
          - name: centos-7-small  # defines label that will be used to get one of these in a job
            flavor-name: 'm1.small'  # name of flavor from cloud
            cloud-image: centos-7  # matches name from cloud-images
            key-name: nodepool # name of the keypair to use for authentication

labels:
  - name: centos-7-small # defines label that will be used in jobs
    min-ready: 2  # nodepool will always keep this many booted and ready to go
EOF"

Warning

min-ready:2 may incur costs in your cloud provider. This will result in two instances always running, even when idle.