Creating new Kubernetes clusters
By employing OpenStack Magnum you can create Kubernetes clusters via OpenStack, using the OpenStack CLI.
Prerequisites
First and foremost, you need an account in Cleura Cloud. You also need to enable the OpenStack CLI.
Then, in addition to the Python openstackclient module, make sure you also install the corresponding plugin module for Magnum.
Use either the package manager of your operating system or pip:
apt install python3-magnumclient
This Python module is unavailable via brew, but you can install it via pip.
pip install python-magnumclient
Creating a Kubernetes cluster
A simple, general command for creating a new Kubernetes cluster with Magnum looks like this:
openstack coe cluster create \
--cluster-template $CLUSTER_TMPL \
--keypair $KEYPAIR \
$CLUSTER_NAME
You can now list all available templates in the region:
openstack coe cluster template list
+--------------------------------------+----------------------------------------------------------------+------+
| uuid | name | tags |
+--------------------------------------+----------------------------------------------------------------+------+
| 3f476f01-b3de-4687-a188-6829ed947db0 | Kubernetes 1.15.5 on Fedora-atomic 29 4C-8GB-20GB No Master LB | None |
| c458f02d-54b0-4ef8-abbc-e1c25b61165a | Kubernetes 1.15.5 on Fedora-atomic 29 2C-4GB-20GB No Master LB | None |
| f9e1a2ea-b1ff-43e7-8d1e-6dd5861b82cf | Kubernetes 1.18.6 on Fedora-coreos 33 2C-4GB-20GB No Master LB | None |
+--------------------------------------+----------------------------------------------------------------+------+
Select the template you want by setting the corresponding uuid value to the CLUSTER_TMPL variable:
CLUSTER_TMPL="f9e1a2ea-b1ff-43e7-8d1e-6dd5861b82cf" # just an example
Then, list all available keypairs…
openstack keypair list
+---------+-------------------------------------------------+------+
| Name | Fingerprint | Type |
+---------+-------------------------------------------------+------+
| husavik | 34:3b:58:ba:ec:95:f5:17:17:df:04:38:11:89:e6:3d | ssh |
+---------+-------------------------------------------------+------+
…and set the KEYPAIR variable to the name of the keypair you want:
KEYPAIR="husavik" # again, this is just an example
Finally, decide on a name for your new Kubernetes cluster:
CLUSTER_NAME="bangor"
With everything in place, go ahead and create your new Kubernetes cluster:
openstack coe cluster create \
--cluster-template $CLUSTER_TMPL \
--keypair husavik
bangor
Request to create cluster e0df8c62-c6f6-4c7d-b67e-33e3606e9ab6 accepted
The cluster creation process takes some time to complete, and while you are waiting, you can check if everything is progressing smoothly:
openstack coe cluster list -c status
If everything is going well, the message you will get will be CREATE_IN_PROGRESS.
When Magnum has finished creating the cluster, the message will be CREATE_COMPLETE.
Viewing the Kubernetes cluster
After the Kubernetes cluster is ready, you may at any time view it and get detailed information about it.
To list all available Kubernetes clusters, type:
openstack coe cluster list
+---------------+--------+---------+------------+--------------+---------------+---------------+
| uuid | name | keypair | node_count | master_count | status | health_status |
+---------------+--------+---------+------------+--------------+---------------+---------------+
| e0df8c62-c6f6 | bangor | husavik | 1 | 1 | CREATE_COMPLE | HEALTHY |
| -4c7d-b67e-33 | | | | | TE | |
| e3606e9ab6 | | | | | | |
+---------------+--------+---------+------------+--------------+---------------+---------------+
For many more details on a specific cluster, note its name and run a command like this:
openstack coe cluster show bangor
+----------------------+---------------------------------------------------------------------------+
| Field | Value |
+----------------------+---------------------------------------------------------------------------+
| status | CREATE_COMPLETE |
| health_status | HEALTHY |
| cluster_template_id | f9e1a2ea-b1ff-43e7-8d1e-6dd5861b82cf |
| node_addresses | ['192.0.2.105'] |
| uuid | e0df8c62-c6f6-4c7d-b67e-33e3606e9ab6 |
| stack_id | e3725aed-f665-4e8d-9409-85f5ee5e2f4a |
| status_reason | None |
| created_at | 2022-11-14T07:32:02+00:00 |
| updated_at | 2022-11-14T07:37:26+00:00 |
| coe_version | v1.18.6 |
| labels | {'kube_tag': 'v1.18.6', 'heat_container_agent_tag': 'train-stable'} |
| labels_overridden | {} |
| labels_skipped | {} |
| labels_added | {} |
| fixed_network | None |
| fixed_subnet | None |
| floating_ip_enabled | True |
| faults | |
| keypair | husavik |
| api_address | https://192.0.2.136:6443 |
| master_addresses | ['192.0.2.136'] |
| master_lb_enabled | False |
| create_timeout | 60 |
| node_count | 1 |
| discovery_url | https://discovery.etcd.io/23af721dc3ee773d2674db4881ff70cb |
| docker_volume_size | 50 |
| master_count | 1 |
| container_version | 1.12.6 |
| name | bangor |
| master_flavor_id | 2C-4GB-20GB |
| flavor_id | 2C-4GB-20GB |
| health_status_reason | {'bangor-id6nijycp2wy-master-0.Ready': 'True', 'bangor-id6nijycp2wy- |
| | node-0.Ready': 'True', 'api': 'ok'} |
| project_id | dfc700467396428bacba4376e72cc3e9 |
+----------------------+---------------------------------------------------------------------------+
Accessing the Kubernetes cluster with kubectl
You may install the Kubernetes command line tool, kubectl, on your local computer, and run commands against your cluster.
To install kubectl, use the package manager of your operating system.
apt install kubectl
brew install kubectl
Before running commands against a specific cluster, you must have the corresponding kubeconfig file on your computer.
To download the kubeconfig file for your Kubernetes cluster, type the following:
openstack coe cluster config --dir=${PWD} bangor
After saving the kubeconfig file locally, set the value of variable KUBECONFIG to the full path of the file.
Type, for example:
export KUBECONFIG=${PWD}/config
Then, you can use kubectl to run commands against your cluster.
See, for instance, all cluster nodes …
kubectl get nodes
NAME STATUS ROLES AGE VERSION
bangor-id6nijycp2wy-master-0 Ready master 113m v1.18.6
bangor-id6nijycp2wy-node-0 Ready <none> 111m v1.18.6
… or all running pods in every namespace:
kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-786ffb7797-tw2hg 1/1 Running 0 167m
kube-system coredns-786ffb7797-vbqwn 1/1 Running 0 167m
kube-system csi-cinder-controllerplugin-0 5/5 Running 0 167m
kube-system csi-cinder-nodeplugin-4nr69 2/2 Running 0 166m
kube-system csi-cinder-nodeplugin-vtwqf 2/2 Running 0 167m
kube-system dashboard-metrics-scraper-6b4884c9d5-4mlrg 1/1 Running 0 167m
kube-system k8s-keystone-auth-wk5v2 1/1 Running 0 167m
kube-system kube-dns-autoscaler-75859754fd-2wsd9 1/1 Running 0 167m
kube-system kube-flannel-ds-7z9dp 1/1 Running 0 167m
kube-system kube-flannel-ds-dmvk6 1/1 Running 0 166m
kube-system kubernetes-dashboard-c98496485-stn42 1/1 Running 0 167m
kube-system magnum-metrics-server-79556d6999-xdlpm 1/1 Running 0 167m
kube-system npd-5p6gk 1/1 Running 0 165m
kube-system openstack-cloud-controller-manager-44rz9 1/1 Running 0 167m
Created: 2022-11-14