In this article we will walk through creating complete infrastructure pieces on OpenStack that are needed to have a fully provisioned Kubernetes cluster using Terraform and Rancher2. In addition to integration with cloud-provider-openstack and cinder-csi-plugin
Getting started with Infrastructure
- Clone the repository terraform-rancher2 into a folder.
- Go into the openstack folder using
cd openstack/
- Modify the variables in
terraform.tfvars
to match your current cloud environment. it is important to uncomment the varsopenstack_project
,openstack_username
andopenstack_password
or export them as env variables with prefix TF_VAR_* for example:
export TF_VAR_openstack_username=myusername
export TF_VAR_openstack_password=mypassword
export TF_VAR_openstack_project=myproject
- Other variables can be obtained from openstack-cli such as
rancher_node_image_id
,external_network
and flavors by invoking
## image list .. pick an ubuntu image
openstack image list
## network name
openstack network list --external
## flavors
openstack flavor list
RKE configuration can be adjusted and customized in rancher2.tf, you can check the provider documentation at rancher_cluster
NOTE: It is really important to keep kubelet extra_args for the external cloudprovider in order to integrate with cloud-provider-openstackRun
terraform init
to initialize a working directory containing Terraform configuration files.To apply the creation of the environment, Run
terraform apply --auto-approve
and wait for the output after all resources finish the creation
Apply complete! Resources: 25 added, 0 changed, 0 destroyed.
Outputs:
rancher_url = [
"https://xx.xx.xx.xx/",
]
Up to this point, use the rancher_url
from above output and login to rancher instance with username admin
and password defined in rancher_admin_password
. Wait for all kubernetes nodes to be discovered, registered, and active.
Integration with cloud-provider-openstack
As you may notice, that all the nodes have a taint node.cloudprovider.kubernetes.io/uninitialized
. The usage of --cloud-provider=external
flag to the kubelet makes it waiting for the clouder-provider to start the initialization. This marks the node as needing a second initialization from an external controller before it can be scheduled work.
- Edit the file
manifests/cloud-config
with the access information to your openstack environment. - Create a secret containing the cloud configuration in the kube-system namespace
kubectl create secret -n kube-system generic cloud-config --from-file=manifests/cloud-config
- Create RBAC resources and openstack-cloud-controller-manager deamonset and wait for all the pods in kube-system namespace up and running.
kubectl apply -f manifests/cloud-controller-manager-roles.yaml
kubectl apply -f manifests/cloud-controller-manager-role-bindings.yaml
kubectl apply -f manifests/openstack-cloud-controller-manager-ds.yaml
- Create cinder-csi-plugin which are a set of cluster roles, cluster role bindings, statefulsets, and storageClass to communicate with openstack(cinder).
kubectl apply -f manifests/cinder-csi-plugin.yaml
Up to this point, openstack-cloud-controller-manager and cinder-csi-plugin have been deployed, and they're able to obtain valuable information such as External IP addresses and Zone info.
$ kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
demo-master-1 Ready controlplane,etcd 5h v1.17.5 192.168.201.6 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
demo-worker-1 Ready worker 4h57m v1.17.5 192.168.201.4 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
demo-worker-2 Ready worker 4h56m v1.17.5 192.168.201.5 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
Also, as shown in the nodes tab, All nodes are active and labeled by openstack zones.
Scalability
When it comes to scalability with IaaC (infrastructure-as-a-code), it becomes so easy to obtain any desired state in less consumed efforts and time.
All you have to do is to change the number of nodes count_master
or count_worker_nodes
and run terraform apply
again
For example, let's increase the number of count_worker_nodes
by 1
A few minutes later, after refreshing states and applying updates:
Apply complete! Resources: 3 added, 0 changed, 0 destroyed.
Outputs:
rancher_url = [
"https://xx.xx.xx.xx",
]
Couple of minutes for the new node to be registered
$ kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
demo-master-1 Ready controlplane,etcd 28h v1.17.5 192.168.201.6 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
demo-worker-1 Ready worker 28h v1.17.5 192.168.201.4 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
demo-worker-2 Ready worker 28h v1.17.5 192.168.201.5 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
demo-worker-3 Ready worker 2m2s v1.17.5 192.168.201.7 xx.xx.xx.xx Ubuntu 18.04.2 LTS 4.15.0-45-generic docker://19.3.9
NOTE: Scaling down the cluster could be made by decreasing the number of nodes in terrafrom.tfvars
. Node gets deleted, moreover cloud-provider-openstack
detects that and removes it from the cluster
Cleaning up
To clean up all resources created by this terraform, Just run terraform destroy
rootsami / terraform-rancher2
Terraform manifests to create e2e production grade k8s cluster
terraform-rancher2
Terraform manifests to create e2e production-grade Kubernetes cluster on top of cloud providers
Overview
This repo is intended to be for creating complete infrastructure pieces on OpenStack that are needed to have a fully provisioned Kubernetes cluster using Terraform and Rancher2. In addition to integration with cloud-provider-openstack
Getting started with Infrastructure
- Clone the repository terraform-rancher2 into a folder.
- Go into the openstack folder using
cd openstack/
- Modify the variables in
terraform.tfvars
to match your current cloud environment. it is important to uncomment the varsopenstack_project
,openstack_username
andopenstack_password
or export them as env variables with prefix TF_VAR_* for example:
export TF_VAR_openstack_username=myusername
export TF_VAR_openstack_password=mypassword
export TF_VAR_openstack_project=myproject
- Other variables can be obtained from openstack-cli such as
rancher_node_image_id
,external_network
by invoking
## image list
openstack image list
## network name
openstack network list --external
## flavors
openstack flavor list
- Run
terraform init
to initialize a working directory…
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