Kubernetes
This tutorial is part of the Cloud Expert Series.
Back to Cloud ExpertCategory: Advanced
Difficulty: 3 out of 5
Duration: 60 minutes
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Creating a Cluster
A Kubernetes Cluster consists of one or more master nodes, and one or more worker nodes. A client (you) communicates with master nodes using the Kubernetes API to spin up containers. The worker nodes runs these containers.
In this tutorial we start by creating a cluster consisting of one master and one worker node.
Cluster templates
In Magnum, a COE Cluster is created from a Cluster Template. A Cluster Template allows you to specify various configuration options for the Cluster including:
- The Availability Zone
- The Kubernetes version
- The Nova Flavor size for the nodes in the cluster
- The Glance Image for the nodes
- The number of nodes
As the number of configuration options can be overwhelming, Nectar provides
a few default templates to get you started quickly. These templates have
names of the form kubernetes-<az>-version, and they can be listed by
running:
$ openstack coe cluster template list
+--------------------------------------+--------------------------------------+------+
| uuid | name | tags |
+--------------------------------------+--------------------------------------+------+
| 33bb5cb9-0412-4da6-8009-fc5744d28941 | kubernetes-melbourne-v1.23.8 | None |
| 22b7cb4a-4425-40ee-8354-383fe9119837 | kubernetes-melbourne-qh2-uom-v1.23.8 | None |
| 287c9a1f-b0bd-471c-9bf8-80960d55170d | kubernetes-monash-01-v1.23.8 | None |
| bf002770-6a59-4a2e-88a9-c69434a3bba0 | kubernetes-monash-02-v1.23.8 | None |
| 2d58291c-2aec-484a-a652-f23fb78bd1af | kubernetes-intersect-v1.23.8 | None |
| e11a4ef3-063a-4df4-bc2f-bb66d0873fc5 | kubernetes-tasmania-v1.23.8 | None |
| e05591e9-4320-4ee0-b9a2-55f76f0db28c | kubernetes-auckland-v1.23.8 | None |
| abf5b520-125a-45d4-be87-5daa0a7564d5 | kubernetes-QRIScloud-v1.23.8 | None |
| 5da5a489-a5cb-460a-b7d0-c270033824d0 | kubernetes-ardc-mel-1-v1.23.8 | None |
| fcace136-a6d7-41e5-b746-9a5ead67d769 | kubernetes-swinburne-01-v1.23.8 | None |
| 6c2b353b-75b9-4472-b798-b2a7101c522b | kubernetes-melbourne-qh2-v1.25.9 | None |
| c8e79fba-038f-424b-b9cb-7d254037da9f | kubernetes-melbourne-qh2-uom-v1.25.9 | None |
| 1f3b1f01-baa7-46f0-b3a2-1206ca9f6201 | kubernetes-monash-01-v1.25.9 | None |
| 33b19432-647d-429d-ae25-5be2e19ffca3 | kubernetes-monash-02-v1.25.9 | None |
| cd7bb7f1-00dc-4e82-acec-8c3f8fcfc6d8 | kubernetes-intersect-v1.25.9 | None |
| 350e57f1-a610-41e6-a10a-bf8417010760 | kubernetes-tasmania-v1.25.9 | None |
| a73458a3-8e68-440d-99de-fedaff0b8266 | kubernetes-auckland-v1.25.9 | None |
| cafb7e88-a548-47a4-af7a-9360561a1cee | kubernetes-QRIScloud-v1.25.9 | None |
| 01cff241-342e-4605-be22-40ea80ff4fd7 | kubernetes-swinburne-01-v1.25.9 | None |
| 5e1b17b4-fa4f-46df-b3c3-676049c8c8f7 | kubernetes-ardc-mel-1-v1.25.9 | None |
+--------------------------------------+--------------------------------------+------+
Version numbers change, and it is advisable to use the latest
version (unless you hear otherwise). You can examine any of these
templates by running openstack coe cluster template show <id>.
$ openstack coe cluster template show cafb7e88-a548-47a4-af7a-9360561a1cee --max-width 132
+-----------------------+----------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------------+----------------------------------------------------------------------------------------------------------+
| insecure_registry | - |
| labels | {'container_infra_prefix': 'registry.rc.nectar.org.au/nectarmagnum/', 'master_lb_floating_ip_enabled': |
| | 'true', 'cinder_csi_enabled': 'true', 'docker_volume_type': 'standard', 'ingress_controller': 'octavia', |
| | 'container_runtime': 'containerd', 'containerd_version': '1.6.20', 'containerd_tarball_sha256': |
| | '1d86b534c7bba51b78a7eeb1b67dd2ac6c0edeb01c034cc5f590d5ccd824b416', 'kube_tag': 'v1.25.9', |
| | 'flannel_tag': 'v0.21.5', 'cloud_provider_tag': 'v1.25.5', 'cinder_csi_plugin_tag': 'v1.25.5', |
| | 'k8s_keystone_auth_tag': 'v1.25.5', 'octavia_ingress_controller_tag': 'v1.25.5', 'coredns_tag': |
| | '1.10.1', 'csi_snapshotter_tag': 'v6.2.1', 'csi_attacher_tag': 'v4.2.0', 'csi_resizer_tag': 'v1.7.0', |
| | 'csi_provisioner_tag': 'v3.4.1', 'csi_node_driver_registrar_tag': 'v2.8.0', 'availability_zone': |
| | 'QRIScloud'} |
| updated_at | - |
| floating_ip_enabled | False |
| fixed_subnet | - |
| master_flavor_id | m3.small |
| uuid | cafb7e88-a548-47a4-af7a-9360561a1cee |
| no_proxy | - |
| https_proxy | - |
| tls_disabled | False |
| keypair_id | - |
| public | True |
| http_proxy | - |
| docker_volume_size | - |
| server_type | vm |
| external_network_id | QRIScloud |
| cluster_distro | fedora-coreos |
| image_id | fedora-coreos-37 |
| volume_driver | cinder |
| registry_enabled | False |
| docker_storage_driver | overlay2 |
| apiserver_port | - |
| name | kubernetes-QRIScloud-v1.25.9 |
| created_at | 2023-06-07T03:11:12+00:00 |
| network_driver | flannel |
| fixed_network | - |
| coe | kubernetes |
| flavor_id | m3.small |
| master_lb_enabled | True |
| dns_nameserver | 8.8.8.8 |
| hidden | False |
| tags | - |
+-----------------------+----------------------------------------------------------------------------------------------------------+
You can create your own templates with custom options. Use openstack coe
cluster template show <id> on one of the default templates to see the
template options that are appropriate to the AZ that you intend to use. We
strongly recommend that you copy all properties and values from the latest
version of the default template, apart from those that you specifically
want to change.
Note that options cloud_provider_tag and kube_tag are highly dependent on
the current version of the COE driver in Magnum. The latest versions might
not be supported in the Nectar Magnum service yet.
Create a Cluster
Using the openstack command line client
-
Choose a Cluster Template to create your Cluster from.
-
Create the Cluster. Note, we are using the
uuidfrom our cluster template list as the value for our template, and you need to input the name of your ownkeypair.$ openstack coe cluster create --cluster-template cafb7e88-a548-47a4-af7a-9360561a1cee \ --keypair pc-key mycluster Request to create cluster 2444b7b8-364f-4577-a935-04bb437f780d accepted -
List the clusters in your project, and wait for your cluster to reach the
CREATE_COMPLETEstatus. This could take up to 15 minutes.$ openstack coe cluster list +--------------------------------------+----------------------+----------------+------------+--------------+-----------------+---------------+ | uuid | name | keypair | node_count | master_count | status | health_status | +--------------------------------------+----------------------+----------------+------------+--------------+-----------------+---------------+ | 2444b7b8-364f-4577-a935-04bb437f780d | mycluster | pc-key | 1 | 1 | CREATE_COMPLETE | HEALTHY | +--------------------------------------+----------------------+----------------+------------+--------------+-----------------+---------------+