Getting Started with kops on OpenStack

WARNING: OpenStack support on kops is currently beta, which means that OpenStack support is in good shape. However, always some small things might change before we can really say that it is production ready.

The tutorial shown on this page works with kops v1.12 and above.

Source your openstack RC

The Cloud Config used by the kubernetes API server and kubelet will be constructed from environment variables in the openstack RC file. The openrc.sh file is usually located under API access.

  1. source openstack.rc

If you are authenticating by username, OS_DOMAIN_NAME or OS_DOMAIN_ID must manually be set.

  1. export OS_DOMAIN_NAME=<USER_DOMAIN_NAME>

Environment Variables

It is important to set the following environment variables:

  1. export KOPS_STATE_STORE=swift://<bucket-name> # where <bucket-name> is the name of the Swift container to use for kops state

If your OpenStack does not have Swift you can use any other VFS store, such as S3.

Creating a Cluster

  1. # to see your etcd storage type
  2. openstack volume type list
  3.  
  4. # coreos (the default) + flannel overlay cluster in Default
  5. kops create cluster \
  6.   --cloud openstack \
  7.   --name my-cluster.k8s.local \
  8.   --state ${KOPS_STATE_STORE} \
  9.   --zones nova \
  10.   --network-cidr 10.0.0.0/24 \
  11.   --image <imagename> \
  12.   --master-count=3 \
  13.   --node-count=1 \
  14.   --node-size <flavorname> \
  15.   --master-size <flavorname> \
  16.   --etcd-storage-type <volumetype> \
  17.   --api-loadbalancer-type public \
  18.   --topology private \
  19.   --bastion \
  20.   --ssh-public-key ~/.ssh/id_rsa.pub \
  21.   --networking weave \
  22.   --os-ext-net <externalnetworkname>
  23.  
  24. # to update a cluster
  25. kops update cluster my-cluster.k8s.local --state ${KOPS_STATE_STORE} --yes
  26.  
  27. # to delete a cluster
  28. kops delete cluster my-cluster.k8s.local --yes

Optional flags

  • —os-kubelet-ignore-az=true Nova and Cinder have different availability zones, more information Kubernetes docs
  • —os-octavia=true If Octavia Loadbalancer api should be used instead of old lbaas v2 api.
  • —os-dns-servers=8.8.8.8,8.8.4.4 You can define dns servers to be used in your cluster if your openstack setup does not have working dnssetup by default

Compute and volume zone names does not match

Some of the openstack users do not have compute zones named exactly the same than volume zones. Good example is that there are several compute zones for instance zone-1, zone-2 and zone-3. Then there is only one volumezone which is usually called nova. By default this is problem in kops, because kops assumes that if you are deploying things to zone-1 there should be compute and volume zone called zone-1.

However, you can still get kops working in your openstack by doing following:

Create cluster using your compute zones

  1. kops create cluster \
  2.   ...
  3.   --zones zone-1,zone-2,zone-3 \
  4.   ...

After you have initialized the configuration you need to edit configuration

  1. kops edit cluster my-cluster.k8s.local

Edit ignore-volume-az to true and override-volume-az according to your cinder az name.

Example (volume zone is called nova):

  1. spec:
  2.   ...
  3.   cloudConfig:
  4.     openstack:
  5.       blockStorage:
  6.         ignore-volume-az: true
  7.         override-volume-az: nova
  8.   ...

Finally execute update cluster

  1. kops update cluster my-cluster.k8s.local --state ${KOPS_STATE_STORE} --yes

Kops should create instances to all three zones, but provision volumes from the same zone.

Using external cloud controller manager

If you want use External CCM in your installation, this section contains instructions what you should do to get it up and running.

Enable featureflag:

  1. export KOPS_FEATURE_FLAGS=EnableExternalCloudController

Create cluster without —yes flag (or modify existing cluster):

  1. kops edit cluster <cluster>

Add following to clusterspec:

  1.   cloudControllerManager: {}

Finally

  1. kops update cluster --name <cluster> --yes

Using OpenStack without lbaas

Some OpenStack installations does not include installation of lbaas component. That is why we have added very-experimental support of installing OpenStack kops without lbaas. You can install it using:

  1. kops create cluster \
  2.   --cloud openstack \
  3.   ... (like usually)
  4.   --api-loadbalancer-type=""

The biggest problem currently when installing without loadbalancer is that kubectl requests outside cluster is always going to first master. External loadbalancer is one option which can solve this issue.

Using existing OpenStack network

Warning! This feature is experimental use only if you know what you are doing.

By default KOPS will always create new network to your OpenStack project which name matches to your clustername. However, there is experimental feature to use existing network in OpenStack project. When you create new cluster you can specify flag —os-network <network id> and it will then use existing network.

Using yaml this can be specified to yaml:

  1. spec:
  2.   ...
  3.   networkID: <network id>
  4.   ...

Warning! when deleting cluster, you need to be really careful that you do not break another dependencies under same network. Run kops delete cluster without —yes flag and go through the list. Otherwise you might see situation that you broke something else.

Using existing OpenStack subnets

Warning! This feature is experimental use only if you know what you are doing.

By default KOPS will always create new network and subnet to your OpenStack project. However, there is experimental feature to use existing network and subnets in OpenStack project. When you create new cluster you can specify flag —subnets <commaseparated list of subnetids> and it will then use existing subnet. There is similar flag for utility subnets —utility-subnets <commaseparated list of subnetids>.

Example:

  1. kops create cluster \
  2.   --cloud openstack \
  3.   --name sharedsub2.k8s.local \
  4.   --state ${KOPS_STATE_STORE} \
  5.   --zones zone-1 \
  6.   --network-cidr 10.1.0.0/16 \
  7.   --image debian-10-160819-devops \
  8.   --master-count=3 \
  9.   --node-count=2 \
  10.   --node-size m1.small \
  11.   --master-size m1.small \
  12.   --etcd-storage-type default \
  13.   --topology private \
  14.   --bastion \
  15.   --networking calico \
  16.   --api-loadbalancer-type public \
  17.   --os-kubelet-ignore-az=true \
  18.   --os-ext-net ext-net \
  19.   --subnets c7d20c0f-df3a-4e5b-842f-f633c182961f \
  20.   --utility-subnets 90871d21-b546-4c4a-a7c9-2337ddf5375f \
  21.   --os-octavia=true --yes

Warning! when deleting cluster, you need to be really careful that you do not break another dependencies under same network & subnet. Run kops delete cluster without —yes flag and go through the list. Otherwise you might see situation that you broke something else.

Using with self-signed certificates in OpenStack

Kops can be configured to use insecure mode towards OpenStack. However, this is NOT recommended as OpenStack cloudprovider in kubernetes does not support it.If you use insecure flag in kops - it might be that the cluster does not work correctly.

  1. spec:
  2.   ...
  3.   cloudConfig:
  4.     openstack:
  5.       insecureSkipVerify: true
  6.   ...