Lona umhlahlandlela wesinyathelo ngesinyathelo ekusetheni i-Kubernetes ku-Scaleway bare-metal ARM kanye ne-x86-64. Isizathu esiyinhloko sokuthi ngisebenze kule phrojekthi ukuthi bengifuna ukwenza ngokuzenzakalelayo ukudalwa kwezindawo zokuhlola ze-OpenFaaS ne-Weave Net ku-ARM. Bengifuna isixazululo esishibhile sokuqalisa izivivinyo zokuhlanganisa nangemuva kokuzama abahlinzeki befu abambalwa be-IâÂÂve ngizinze ku-Scaleway. I-Scaleway ingumhlinzeki wamafu wase-french onikeza i-ARM yensimbi engenalutho kanye namaseva e-x86-64 ngamanani athengekayo. Usebenzisa umhlinzeki we-Terraform Scaleway kanye ne-kubeadm ungaba neqoqo le-Kubernetes elisebenza ngokugcwele ngemizuzu eyishumi.
Ukusetha kokuqala
Vala indawo yokugcina bese ufaka okuncikile:
$ git clone httpsgithub.com/stefanprodan/k8s-scw-baremetal.git $ cd k8s-scw-baremetal $ terraform init
Qaphela ukuthi uzodinga i-Terraform v0.10 noma entsha ukuze uqalise le phrojekthi
Ngaphambi kokusebenzisa iphrojekthi kuzodingeka udale ithokheni yokufinyelela ukuze i-Terraform ixhume ku-Scaleway API. Usebenzisa ithokheni nokhiye wakho wokufinyelela, dala okuguquguqukayo kwemvelo okubili:
$ thekelisa SCALEWAY_ORGANIZATIONACCESS-KEY>"$ thekelisa SCALEWAY_TOKENACCESS-TOKEN>"Ukusetshenziswa
Dala iqoqo le-Kubernetes le-ARMv7 elingenalutho elinenkosi eyodwa namanodi amabili:
$ terraform indawo yokusebenza ingalo entsha $ terraform iyasebenza \ -var region=par1 \ -var arch=arm \ -var server_type=C1 \ -var nodes=2 \ -var weave_passwd=ChangeMe \ -var k8s_version=stable-1.9 \ -var docker_version =17.03.0~ce-0~ubuntu-xenial
Lokhu kuzokwenza okulandelayo:
- igcina ama-IP omphakathi kuseva ngayinye
- ihlinzeka ngamaseva amathathu ensimbi angenalutho ano-Ubuntu 16.04.1 LTS
- ixhuma kuseva eyinhloko nge-SSH bese ifaka i-Docker CE kanye namaphakheji we-kubeadm armhf apt
- isebenzisa i-beadm init kuseva eyinhloko futhi ilungiselela i-kubectl
- ilanda ifayela le-kubectl admin config emshinini wangakini futhi ithathela i-IP eyimfihlo esikhundleni seyomphakathi
- kwakha imfihlo ye-Kubernetes nge-password ye-Weave Net
- ifaka i-Weave Net enembondela ebethelwe
- ifaka izengezo zeqoqo (ideshibhodi ye-Kubernetes, iseva yamamethrikhi ne-Heapster)
- iqala amanodi ezisebenzi ngokuhambisana bese ifaka i-Docker CE ne-kubeadm
- ujoyina amanodi ezisebenzi kuqoqo usebenzisa ithokheni ye-kubeadm etholwe kunkosi
Khulisa ngokwandisa inani lamanodi:
$ terraform isicelo -var nodes=3
Ukudiliza yonke ingqalasizinda ngalokhu:
i-terraform-force
Dala iqoqo le-Kubernetes le-AMD64 elingenalutho elinenkosi eyodwa nenodi:
Indawo yokusebenza engu-$ terraform entsha amd64 $ terraform iyasebenza \ -var region=par1 \ -var arch=x86_64 \ -var server_type=C2S \ -var nodes=1 \ -var weave_passwd=ChangeMe \ -var k8s_version=stable-1.9 \ -var docker_version =17.03.0~ce-0~ubuntu-xenial
Isilawuli kude
Ngemva kokusebenzisa uhlelo lwe-Terraform uzobona okuhlukile kokuphumayo okuningana njenge-IP yomphakathi eyinhloko, umyalo wokujoyina we-kubeadmn kanye nokulungiselelwa kwamanje kwendawo yokusebenza.
Ukuze ugijime
imiyalo ye-kubectl ngokumelene neqoqo le-Scaleway ongayisebenzisa
kubectl_config okukhiphayo okuguquguqukayo:
Hlola ukuthi i-Heapster iyasebenza:
$ kubectl --kubeconfig terraform okukhiphayo kubectl_config) izindawo eziphezulu NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% arm-master-1 655m 16% 873Mi 45% arm-node-1 147m 3% 618Mi 32% arm-node- 2 101m 2% 584Mi 30%
I
Ifomethi yefayela le-kubectl yi
.conf as in
arm.conf or
amd64.conf
In order to access the dashboard youâÂÂll need to find its cluster IP:
$ kubectl --kubeconfig terraform output kubectl_config) \ -n kube-system get svc --selector=k8s-app=kubernetes-dashboard NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes-dashboard ClusterIP 10.107.37.220 80/TCP 6m
Open a SSH tunnel:
ssh -L 8888::80 [email protected]
Now you can access the dashboard on your computer at
httplocalhost:8888
Expose services outside the cluster
Since weâÂÂre running on bare-metal and Scaleway doesnâÂÂt offer a load balancer, the easiest way to expose applications outside of Kubernetes is using a NodePort service
LetâÂÂs deploy the podinfo app in the default namespace. Podinfo has a multi-arch Docker image and it will work on arm, arm64 or amd64
Create the podinfo nodeport service:
$ kubectl --kubeconfig terraform output kubectl_config) \ apply -f httpsraw.githubusercontent.com/stefanprodan/k8s-podinfo/master/deploy/auto-scaling/podinfo-svc-nodeport.yaml service "podinfo-nodeport" created
Create the podinfo deployment:
$ kubectl --kubeconfig terraform output kubectl_config) \ apply -f httpsraw.githubusercontent.com/stefanprodan/k8s-podinfo/master/deploy/auto-scaling/podinfo-dep.yaml deployment "podinfo" created
Inspect the podinfo service to obtain the port number:
$ kubectl --kubeconfig terraform output kubectl_config) \ get svc --selector=app=podinfo NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE podinfo-nodeport NodePort 10.104.132.14 9898:31190/TCP 3m
You can access podinfo at
httpMASTER_PUBLIC_IP>:31190 or using curl:
$ curl httpterraform output k8s_master_public_ip):31190 runtime: arch: arm max_procs: "4" num_cpu: "4" num_goroutine: "12" os: linux version: go1.9.2 labels: app: podinfo pod-template-hash: "1847780700" annotations: kubernetes.io/config.seen: 2018-01-08T00:39:45.580597397Z kubernetes.io/config.source: api environment: HOME: /root HOSTNAME: podinfo-5d8ccd4c44-zrczc KUBERNETES_PORT: tcp10.96.0.1:443 KUBERNETES_PORT_443_TCP: tcp10.96.0.1:443 KUBERNETES_PORT_443_TCP_ADDR: 10.96.0.1 KUBERNETES_PORT_443_TCP_PORT: "443" KUBERNETES_PORT_443_TCP_PROTO: tcp KUBERNETES_SERVICE_HOST: 10.96.0.1 KUBERNETES_SERVICE_PORT: "443" KUBERNETES_SERVICE_PORT_HTTPS: "443" PATH: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin externalIP: IPv4: 163.172.139.112
OpenFaaS
You can deploy OpenFaaS on Kubernetes with Helm or by using the YAML files form the faas-netes repository
Clone the faas-netes repo:
git clone httpsgithub.com/openfaas/faas-netes cd faas-netes
Deploy OpenFaaS for ARM:
$ kubectl --kubeconfig terraform output kubectl_config) \ apply -f ./namespaces.ymlyaml_armhf
Deploy OpenFaaS for AMD64:
$ kubectl --kubeconfig terraform output kubectl_config) \ apply -f ./namespaces.ymlyaml
You can access the OpenFaaS gateway at
httpMASTER_PUBLIC_IP>:31112
Horizontal Pod Autoscaling
Starting from Kubernetes 1.9
kube-controller-manager is configured by default with
horizontal-pod-autoscaler-use-rest-clients
In order to use HPA we need to install the metrics server to enable the new metrics API used by HPA v2
Both Heapster and the metrics server have been deployed from Terraform
when the master node was provisioned
The metric server collects resource usage data from each node using Kubelet Summary API. Check if the metrics server is running:
$ kubectl --kubeconfig terraform output kubectl_config) \ get --raw "/apis/metrics.k8s.io/v1beta1/nodes" | jq
{ "kind": "NodeMetricsList", "apiVersion": "metrics.k8s.io/v1beta1", "metadata": { "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes" }, "items": [ { "metadata": { "name": "arm-master-1", "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/arm-master-1", "creationTimestamp": "2018-01-08T15:17:09Z" }, "timestamp": "2018-01-08T15:17:00Z", "window": "1m0s", "usage": { "cpu": "384m", "memory": "935792Ki" } }, { "metadata": { "name": "arm-node-1", "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/arm-node-1", "creationTimestamp": "2018-01-08T15:17:09Z" }, "timestamp": "2018-01-08T15:17:00Z", "window": "1m0s", "usage": { "cpu": "130m", "memory": "649020Ki" } }, { "metadata": { "name": "arm-node-2", "selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/arm-node-2", "creationTimestamp": "2018-01-08T15:17:09Z" }, "timestamp": "2018-01-08T15:17:00Z", "window": "1m0s", "usage": { "cpu": "120m", "memory": "614180Ki" } } ] }
LetâÂÂs define a HPA that will maintain a minimum of two replicas and will scale up to ten if the CPU average is over 80% or if the memory goes over 200Mi
apiVersion: autoscaling/v2beta1 kind: HorizontalPodAutoscaler metadata: name: podinfo spec: scaleTargetRef: apiVersion: apps/v1beta1 kind: Deployment name: podinfo minReplicas: 2 maxReplicas: 10 metrics: - type: Resource resource: name: cpu targetAverageUtilization: 80 - type: Resource resource: name: memory targetAverageValue: 200Mi
Apply the podinfo HPA:
$ kubectl --kubeconfig terraform output kubectl_config) \ apply -f httpsraw.githubusercontent.com/stefanprodan/k8s-podinfo/master/deploy/auto-scaling/podinfo-hpa.yaml horizontalpodautoscaler "podinfo" created
After a couple of seconds the HPA controller will contact the metrics server and will fetch the CPU and memory usage:
$ kubectl --kubeconfig terraform output kubectl_config) get hpa NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE podinfo Deployment/podinfo 2826240 / 200Mi, 15% / 80% 2 10 2 5m
In order to increase the CPU usage we could run a load test with hey:
#install hey go get -u github.com/rakyll/hey #do 10K requests rate limited at 20 QPS hey -n 10000 -q 10 -c 5 httpterraform output k8s_master_public_ip):31190
You can monitor the autoscaler events with:
$ kubectl --kubeconfig terraform output kubectl_config) describe hpa Events: Type Reason Age From MessageNormal SuccessfulRescale 7m horizontal-pod-autoscaler New size: 4; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 3m horizontal-pod-autoscaler New size: 8; reason: cpu resource utilization (percentage of request) above target
After the load tests finishes the autoscaler will remove replicas until the deployment reaches the initial replica count:
Events: Type Reason Age From MessageNormal SuccessfulRescale 20m horizontal-pod-autoscaler New size: 4; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 16m horizontal-pod-autoscaler New size: 8; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 12m horizontal-pod-autoscaler New size: 10; reason: cpu resource utilization (percentage of request) above target Normal SuccessfulRescale 6m horizontal-pod-autoscaler New size: 2; reason: All metrics below target
Conclusions
Thanks to kubeadm and Terraform, bootstrapping a Kubernetes cluster on bare-metal can be done with a single command and it takes just ten minutes to have a fully functional setup. If you have any suggestion on improving this guide please submit an issue or PR on GitHub at stefanprodan/k8s-scw-baremetal. Contributions are more than welcome!
UStefan Prodan
