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1. 설치 환경

[그림 1] Kubernetes 설치 환경

[그림 1]은 Kubernetes 설치 환경을 나타내고 있다. 설치 환경은 다음과 같다.

2. OpenStack OpenRC 설정

OpenStack 구성에 맞게 OpenRC 파일을 작성한다.

export OS_PROJECT_DOMAIN_NAME=default
export OS_USER_DOMAIN_NAME=default
export OS_PROJECT_NAME=admin
export OS_USERNAME=admin
export OS_PASSWORD=admin
export OS_AUTH_URL=http://192.168.0.40:5000/v3
export OS_IDENTITY_API_VERSION=3
export OS_IMAGE_API_VERSION=2
[파일 1] admin-openrc.sh

[파일 1]의 내용을 갖고 있는 admin-openrc.sh 파일을 생성한다.

3. Local Kubernetes Cluster 설치

(Local)# GO111MODULE="on" go get sigs.k8s.io/kind@v0.9.0 && kind create cluster
(Local)# kubectl cluster-info
Kubernetes master is running at https://127.0.0.1:34839
KubeDNS is running at https://127.0.0.1:34839/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

Cluster API 구동하기 위한 Local Kubernetes Cluster를 설치하고 구동을 확인한다.

4. clusterctl 설치

(Local)# snap install yq

clusterctl에서 이용하는 yq를 설치한다.

(Local)# curl -L https://github.com/kubernetes-sigs/cluster-api/releases/download/v0.3.11/clusterctl-linux-amd64 -o clusterctl
(Local)# chmod +x ./clusterctl
(Local)# sudo mv ./clusterctl /usr/local/bin/clusterctl
(Local)# clusterctl version                                                                                                   [15:57:48]
clusterctl version: &version.Info{Major:"0", Minor:"3", GitVersion:"v0.3.11", GitCommit:"e9cf6846b6d93dedadfcf44c00357d15f5ccba64", GitTreeState:"clean", BuildDate:"2020-11-19T18:49:17Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

Cluster API를 Local Kubernetes Cluster에 설치하고 이용하도록 도와주는 clusterctl를 설치한다.

5. Cluster API 설치

(Local)# clusterctl init --infrastructure openstack
(Local)# kubectl get pod --all-namespaces
capi-kubeadm-bootstrap-system       capi-kubeadm-bootstrap-controller-manager-6b6579d56d-q7cfm       2/2     Running   0          2m44s
capi-kubeadm-control-plane-system   capi-kubeadm-control-plane-controller-manager-6d878bb599-4wh7h   2/2     Running   0          2m43s
capi-system                         capi-controller-manager-7ff4999d6c-252dk                         2/2     Running   0          2m45s
capi-webhook-system                 capi-controller-manager-6c48f8f9bb-qknwx                         2/2     Running   0          2m45s
capi-webhook-system                 capi-kubeadm-bootstrap-controller-manager-56f98bc7f9-whkgb       2/2     Running   0          2m44s
capi-webhook-system                 capi-kubeadm-control-plane-controller-manager-85bcfd7fcd-hxs4v   2/2     Running   0          2m43s
capi-webhook-system                 capo-controller-manager-cc997bf9-vpqxd                           2/2     Running   0          2m43s
capo-system                         capo-controller-manager-64f4d7f476-95fln                         2/2     Running   0          2m42s
cert-manager                        cert-manager-cainjector-fc6c787db-jknzr                          1/1     Running   0          3m17s
cert-manager                        cert-manager-d994d94d7-rrbjg                                     1/1     Running   0          3m17s
cert-manager                        cert-manager-webhook-845d9df8bf-9m4l8                            1/1     Running   0          3m17s
...

clusterctl을 이용하여 Local Kubernetes Cluster에 Cluster API를 설치한다.

(Local)# kubectl -n capo-system set env deployment/capo-controller-manager CLUSTER_API_OPENSTACK_INSTANCE_CREATE_TIMEOUT=60

OpenStack Controller Manager가 Instance 생성시 최대 60분 대기하도록 설정한다.

6. VM Image Build, Import

Cluster API를 통해서 생성할 Kubernetes Cluster Node의 VM Image를 Build 한다.

(Local)# apt install qemu-kvm libvirt-bin qemu-utils

VM Image Build에 필요한 Ubuntu Package를 설치한다.

(Local)# apt install python3-pip
(Local)# pip3 install ansible --user
(Local)# export PATH=$PATH:$HOME/.local/bin

Ansible을 설치한다.

(Local)# export VER="1.6.5"
(Local)# wget "https://releases.hashicorp.com/packer/${VER}/packer_${VER}_linux_amd64.zip"
(Local)# unzip packer_1.6.5_linux_amd64.zip 
(Local)# sudo mv packer /usr/local/bin 

packer를 설치한다.

(Local)# curl -L https://github.com/kubernetes-sigs/image-builder/tarball/master -o image-builder.tgz
(Local)# tar xzf image-builder.tgz
(Local)# cd kubernetes-sigs-image-builder-3c3a17/images/capi
(Local)# make build-qemu-ubuntu-1804

VM Image를 Build 하고 Size를 줄인다. Image를 Build 하기 위해서는 KVM이 지원되는 환경이어야 한다. Build된 Image는 QCOW2 Format을 갖는다.

(Local)# . admin-openrc.sh
(Local)# openstack image create --disk-format qcow2 --container-format bare --public --file ./output/ubuntu-1804-kube-v1.17.11/ubuntu-1804-kube-v1.17.11 ubuntu-18.04-capi

Build된 Image를 OpenStack에 Import한다.

7. Openstack 설정

Cluster API를 위한 OpenStack을 설정한다.

(Local)# . admin-openrc.sh
(Local)# openstack keypair create --private-key ssup2_pri.key ssup2

Cluster API를 통해서 생성할 Kubernetes Cluster Node에 설정할 Keypair를 생성한다.

(Local)# . admin-openrc.sh
(Local)# openstack application credential create cloud-controller-manager
+--------------+----------------------------------------------------------------------------------------+
| Field        | Value                                                                                  |
+--------------+----------------------------------------------------------------------------------------+
| description  | None                                                                                   |
| expires_at   | None                                                                                   |
| id           | 96e2f01837884a59b5d70fa8a6960c9a                                                       |
| name         | cloud-controller-manager                                                               |
| project_id   | b21b68637237488bbb5f33ac8d86b848                                                       |
| roles        | admin member reader                                                                    |
| secret       | nKhWeYW0zEbkIqO4V8ubVXoHQDsfc8U8Z-eJ-up2JtvyxHWujeCB47XKJcvmaLcQjX0Qxg7CffgqwM0pdyeaww |
| system       | None                                                                                   |
| unrestricted | False                                                                                  |
| user_id      | f2bf159333f245b49240d1444f449e33                                                       |
+--------------+----------------------------------------------------------------------------------------+

OpenStack Cloud Controller Manager에서 이용할 application credential을 생성한다.

8. Kubernetes Cluster 생성

clouds:
  openstack:
    insecure: true
    verify: false
    identity_api_version: 3
    auth:
      auth_url: http://192.168.0.40:5000/v3
      project_name: admin
      username: admin
      password: admin
      project_domain_name: default
      user_domain_name: default
    region: RegionOne
[파일 2] clouds.yaml

clusterctl에서 이용할 [파일 2]의 내용을 갖고 있는 clouds.yaml 파일을 생성한다.

---
apiVersion: cluster.x-k8s.io/v1alpha3
kind: Cluster
metadata:
  name: ${CLUSTER_NAME}
spec:
  clusterNetwork:
    pods:
      cidrBlocks: ["192.167.0.0/16"]
    serviceDomain: "cluster.local"
  infrastructureRef:
    apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
    kind: OpenStackCluster
    name: ${CLUSTER_NAME}
  controlPlaneRef:
    kind: KubeadmControlPlane
    apiVersion: controlplane.cluster.x-k8s.io/v1alpha3
    name: ${CLUSTER_NAME}-control-plane
---
apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
kind: OpenStackCluster
metadata:
  name: ${CLUSTER_NAME}
spec:
  cloudName: ${OPENSTACK_CLOUD}
  cloudsSecret:
    name: ${CLUSTER_NAME}-cloud-config
    namespace: ${NAMESPACE}
  managedAPIServerLoadBalancer: true
  managedSecurityGroups: true
  nodeCidr: 10.6.0.0/24
  dnsNameservers:
  - ${OPENSTACK_DNS_NAMESERVERS}
  disablePortSecurity: false
  useOctavia: true
  bastion:
    enabled: true
    flavor: m1.medium
    image: ubuntu-18.04-capi
    sshKeyName: ssup2
---
apiVersion: controlplane.cluster.x-k8s.io/v1alpha3
kind: KubeadmControlPlane
metadata:
  name: "${CLUSTER_NAME}-control-plane"
spec:
  replicas: ${CONTROL_PLANE_MACHINE_COUNT}
  infrastructureTemplate:
    kind: OpenStackMachineTemplate
    apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
    name: "${CLUSTER_NAME}-control-plane"
  kubeadmConfigSpec:
    initConfiguration:
      nodeRegistration:
        name: ''
        kubeletExtraArgs:
          cloud-provider: external
    clusterConfiguration:
      imageRepository: k8s.gcr.io
      apiServer:
        extraArgs:
          cloud-provider: external
      controllerManager:
        extraArgs:
          cloud-provider: external
    joinConfiguration:
      nodeRegistration:
        name: ''
        kubeletExtraArgs:
          cloud-provider: external
  version: "${KUBERNETES_VERSION}"
---
apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
kind: OpenStackMachineTemplate
metadata:
  name: ${CLUSTER_NAME}-control-plane
spec:
  template:
    spec:
      flavor: ${OPENSTACK_CONTROL_PLANE_MACHINE_FLAVOR}
      image: ${OPENSTACK_IMAGE_NAME}
      sshKeyName: ${OPENSTACK_SSH_KEY_NAME}
      cloudName: ${OPENSTACK_CLOUD}
      cloudsSecret:
        name: ${CLUSTER_NAME}-cloud-config
        namespace: ${NAMESPACE}
---
apiVersion: cluster.x-k8s.io/v1alpha3
kind: MachineDeployment
metadata:
  name: "${CLUSTER_NAME}-md-0"
spec:
  clusterName: "${CLUSTER_NAME}"
  replicas: ${WORKER_MACHINE_COUNT}
  selector:
    matchLabels:
  template:
    spec:
      clusterName: "${CLUSTER_NAME}"
      version: "${KUBERNETES_VERSION}"
      failureDomain: ${OPENSTACK_FAILURE_DOMAIN}
      bootstrap:
        configRef:
          name: "${CLUSTER_NAME}-md-0"
          apiVersion: bootstrap.cluster.x-k8s.io/v1alpha3
          kind: KubeadmConfigTemplate
      infrastructureRef:
        name: "${CLUSTER_NAME}-md-0"
        apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
        kind: OpenStackMachineTemplate
---
apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
kind: OpenStackMachineTemplate
metadata:
  name: ${CLUSTER_NAME}-md-0
spec:
  template:
    spec:
      cloudName: ${OPENSTACK_CLOUD}
      cloudsSecret:
        name: ${CLUSTER_NAME}-cloud-config
        namespace: ${NAMESPACE}
      flavor: ${OPENSTACK_NODE_MACHINE_FLAVOR}
      image: ${OPENSTACK_IMAGE_NAME}
      sshKeyName: ${OPENSTACK_SSH_KEY_NAME}
---
apiVersion: bootstrap.cluster.x-k8s.io/v1alpha3
kind: KubeadmConfigTemplate
metadata:
  name: ${CLUSTER_NAME}-md-0
spec:
  template:
    spec:
      joinConfiguration:
        nodeRegistration:
          name: ''
          kubeletExtraArgs:
            cloud-provider: external
---
apiVersion: v1
kind: Secret
metadata:
  name: ${CLUSTER_NAME}-cloud-config
  labels:
    clusterctl.cluster.x-k8s.io/move: "true"
data:
  clouds.yaml: ${OPENSTACK_CLOUD_YAML_B64}
  cacert: ${OPENSTACK_CLOUD_CACERT_B64}
[파일 3] template.yaml

Cluster Manifest Template 역활을 수행하는 [파일 3]의 내용을 갖고 있는 template.yaml 파일을 생성한다. https://raw.githubusercontent.com/kubernetes-sigs/cluster-api-provider-openstack/v0.3.3/templates/cluster-template-external-cloud-provider.yaml 파일에서 "disableServerTags: true" 제거, cidrBlocks을 "192.167.0.0/16"으로 변경, Bastion VM 설정을 추가하였다.

ClusterAPI는 기본적으로 생성한 Kubernetes Cluster의 Node에 SSH 접근이 불가능 하도록 Security Group을 설정한다. Bastion VM은 ClusterAPI를 통해 생성한 Kubernetes Cluster의 Node에 SSH로 접근할 수 있게 만드는 통로 역활을 수행한다.

(Local)# wget https://raw.githubusercontent.com/kubernetes-sigs/cluster-api-provider-openstack/master/templates/env.rc -O env.rc

clusterctl에서 이용할 환경변수를 설정하는 env.rc Script 파일을 받는다.

(Local)# source env.rc clouds.yaml openstack
(Local)# export OPENSTACK_SSH_KEY_NAME=ssup2 \
export OPENSTACK_IMAGE_NAME=ubuntu-18.04-capi \
export OPENSTACK_FAILURE_DOMAIN=nova \
export OPENSTACK_DNS_NAMESERVERS=8.8.8.8 \
export OPENSTACK_CONTROL_PLANE_MACHINE_FLAVOR=m1.medium \
export OPENSTACK_NODE_MACHINE_FLAVOR=m1.medium

clusterctl에서 이용할 환경변수를 설정한다. VM Image, VM Flavor, DNS 등을 환경변수로 설정한다.

(Local)# clusterctl config cluster ssup2 --from template.yaml --kubernetes-version v1.17.11 --control-plane-machine-count=3 --worker-machine-count=1 > ssup2_cluster.yaml
(Local)# kubectl apply -f ssup2_cluster.yaml

Cluster Manifest 파일을 생성하고, 생성한 Cluster Manifest 파일을 이용하여 Kubernetes Cluster를 생성한다.

9. Cilium CNI & OpenStack External Cloud Provider 설치

Kubernetes Cluster를 생성하면 Control Plain (Master Node) VM이 하나만 생성되고, 더 이상 Control Plain이 생성되지 않는다. Control Plain Node VM의 Node Object의 "spec.providerID" 값이 설정 되어있지 않기 때문이다. "spec.providerID" 값은 OpenStack External Cloud Provider가 설치되어야 설정된다.

(Local)# clusterctl get kubeconfig ssup2 > /root/.kube/ssup2.kubeconfig

clusterctl 파일을 이용하여 생성한 Kubernetes Cluster의 kubeconfig 파일을 생성한다.

(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' create -f https://raw.githubusercontent.com/cilium/cilium/1.7.11/install/kubernetes/quick-install.yaml

OpenStack External Cloud Provider 설치전에 Cilium CNI Plugin을 설치하여, OpenStack External Cloud Provider가 설치 될수 있도록 만든다.

[Global]
auth-url="http://192.168.0.40:5000/v3"
application-credential-id="96e2f01837884a59b5d70fa8a6960c9a"
application-credential-secret="nKhWeYW0zEbkIqO4V8ubVXoHQDsfc8U8Z-eJ-up2JtvyxHWujeCB47XKJcvmaLcQjX0Qxg7CffgqwM0pdyeaww"

[BlockStorage]
bs-version=v3

[LoadBalancer]
use-octavia=True
subnet-id=67ca5cfd-0c3f-434d-a16c-c709d1ab37fb
floating-network-id=00a8e738-c81e-45f6-9788-3e58186076b6
lb-method=ROUND_ROBIN
[파일 4] cloud.conf

OpenStack External Cloud Controller Manager에서 이용할 [파일 4]의 내용을 갖고 있는 cloud.conf 파일을 생성한다.

(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' create secret -n kube-system generic cloud-config --from-file=cloud.conf
(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' apply -f https://raw.githubusercontent.com/kubernetes/cloud-provider-openstack/v1.17.0/cluster/addons/rbac/cloud-controller-manager-roles.yaml
(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' apply -f https://raw.githubusercontent.com/kubernetes/cloud-provider-openstack/v1.17.0/cluster/addons/rbac/cloud-controller-manager-role-bindings.yaml
(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' apply -f https://raw.githubusercontent.com/kubernetes/cloud-provider-openstack/v1.17.0/manifests/controller-manager/openstack-cloud-controller-manager-ds.yaml

cloud-config Secret을 생성하고, OpenStack External Cloud Provider를 배포한다.

OpenStack External Cloud Provider를 배포된 이후에 나머지 Control Plain (Master Node) VM이 생성되는걸 확인할 수 있다.

10. Kubernetes Cluster 동작 확인

(Local)# kubectl get cluster
NAME    PHASE
ssup2   Provisioned

(Local)# kubectl get openstackclusters.infrastructure.cluster.x-k8s.io
NAME    CLUSTER   READY   NETWORK                                SUBNET                                 BASTION
ssup2   ssup2     true    678c082d-1b80-4d5b-ad74-4daced3f9379   170d5b4b-6c05-4388-84af-e952dde31e59   192.168.0.56

(Local)# kubectl get kubeadmcontrolplane
NAME                  INITIALIZED   API SERVER AVAILABLE   VERSION    REPLICAS   READY   UPDATED   UNAVAILABLE
ssup2-control-plane   true          true                   v1.17.11   3          3       3

(Local)# kubectl get machine
NAME                          PROVIDERID                                         PHASE     VERSION
ssup2-control-plane-88c9w     openstack://2dcc2ba4-2968-4e5a-8c85-11c61054b015   Running   v1.17.11
ssup2-control-plane-m6hkz     openstack://79608e3b-d863-46ae-84a2-7855175b4450   Running   v1.17.11
ssup2-control-plane-smlkx     openstack://f3214c23-a011-4353-bf9f-6a440097dd5e   Running   v1.17.11
ssup2-md-0-7b7b86d6f7-whvwh   openstack://2facf68d-95e5-4d1a-882f-43b3bcafc2ba   Running   v1.17.11

(Local)# kubectl get openstackmachine
NAME                        CLUSTER   INSTANCESTATE   READY   PROVIDERID                                         MACHINE
ssup2-control-plane-b74l9   ssup2     ACTIVE          true    openstack://f3214c23-a011-4353-bf9f-6a440097dd5e   ssup2-control-plane-smlkx
ssup2-control-plane-l28lt   ssup2     ACTIVE          true    openstack://2dcc2ba4-2968-4e5a-8c85-11c61054b015   ssup2-control-plane-88c9w
ssup2-control-plane-pcrxg   ssup2     ACTIVE          true    openstack://79608e3b-d863-46ae-84a2-7855175b4450   ssup2-control-plane-m6hkz
ssup2-md-0-t5jtt            ssup2     ACTIVE          true    openstack://2facf68d-95e5-4d1a-882f-43b3bcafc2ba   ssup2-md-0-7b7b86d6f7-whvwh

(Local)# kubectl get secrets | grep ssup2
ssup2-ca                    Opaque                                2      28d
ssup2-cloud-config          Opaque                                2      28d
ssup2-control-plane-5wcw6   cluster.x-k8s.io/secret               1      28d
ssup2-control-plane-jlm5n   cluster.x-k8s.io/secret               1      28d
ssup2-control-plane-pwpzr   cluster.x-k8s.io/secret               1      28d
ssup2-etcd                  Opaque                                2      28d
ssup2-kubeconfig            Opaque                                1      28d
ssup2-md-0-sjlj9            cluster.x-k8s.io/secret               1      28d
ssup2-proxy                 Opaque                                2      28d
ssup2-sa                    Opaque                                2      28d

(Local)# kubectl --kubeconfig='/root/.kube/ssup2.kubeconfig' get nodes
NAME                        STATUS   ROLES    AGE     VERSION
ssup2-control-plane-b74l9   Ready    master   94m     v1.17.11
ssup2-control-plane-l28lt   Ready    master   8m28s   v1.17.11
ssup2-control-plane-pcrxg   Ready    master   70m     v1.17.11
ssup2-md-0-t5jtt            Ready    <none>   89m     v1.17.11

Kubernetes Cluster 동작을 확인한다.

11. Kubernetes Cluster VM Node에 SSH 접근

Bastion VM으로 ssup2 Keypair를 이용해 SSH로 접속한 다음, Bastion VM 내부에서 다시 ssup2 Keypair를 이용하여 Kubernetes Cluster VM Node에 접근해야 한다.

12. 참조