Konnectivity 서비스 설정하기
Konnectivity 서비스 설정하기 (Set up Konnectivity service)
Konnectivity 서비스는 제어 플레인에서 클러스터로의 통신을 위한 TCP 수준 프록시를 제공해요.
출처: 문서
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시작하기 전에 (Before you begin)
쿠버네티스 클러스터가 있어야 하고, kubectl 명령줄 도구가 클러스터와 통신하도록 구성되어 있어야 해요. 이 튜토리얼은 제어 플레인 호스트로 동작하지 않는 노드가 최소 두 개 있는 클러스터에서 실행하는 것이 권장돼요. 아직 클러스터가 없다면 minikube로 만들 수 있어요.
Konnectivity 서비스 구성하기
다음 단계에는 이그레스 구성이 필요해요. 예:
apiVersion: apiserver.k8s.io/v1beta1
kind: EgressSelectorConfiguration
egressSelections:
# Since we want to control the egress traffic to the cluster, we use the
# "cluster" as the name. Other supported values are "etcd", and "controlplane".
- name: cluster
connection:
# This controls the protocol between the API Server and the Konnectivity
# server. Supported values are "GRPC" and "HTTPConnect". There is no
# end user visible difference between the two modes. You need to set the
# Konnectivity server to work in the same mode.
proxyProtocol: GRPC
transport:
# This controls what transport the API Server uses to communicate with the
# Konnectivity server. UDS is recommended if the Konnectivity server
# locates on the same machine as the API Server. You need to configure the
# Konnectivity server to listen on the same UDS socket.
# The other supported transport is "tcp". You will need to set up TLS
# config to secure the TCP transport.
uds:
udsName: /etc/kubernetes/konnectivity-server/konnectivity-server.socket
API 서버가 Konnectivity 서비스를 사용하고 네트워크 트래픽을 클러스터 노드로 향하게 하도록 구성해야 해요:
- 클러스터에서 Service Account Token Volume Projection 기능이 활성화되어 있는지 확인해요. 쿠버네티스 v1.20부터 기본으로 활성화돼 있어요.
admin/konnectivity/egress-selector-configuration.yaml같은 이그레스 구성 파일을 만들어요.- API 서버의
--egress-selector-config-file플래그를 API 서버 이그레스 구성 파일의 경로로 설정해요. - UDS 연결을 사용한다면 kube-apiserver에 볼륨 구성을 추가해요:
konnectivity-server용 인증서와 kubeconfig를 생성하거나 얻어요. 예를 들어 OpenSSL 명령줄 도구를 사용해 제어 플레인 호스트의 클러스터 CA 인증서 /etc/kubernetes/pki/ca.crt 로 X.509 인증서를 발급할 수 있어요.
openssl req -subj "/CN=system:konnectivity-server" -new -newkey rsa:2048 -noenc -out konnectivity.csr -keyout konnectivity.key
openssl x509 -req -in konnectivity.csr -CA /etc/kubernetes/pki/ca.crt -CAkey /etc/kubernetes/pki/ca.key -CAcreateserial -out konnectivity.crt -days 375 -sha256
SERVER=$(kubectl config view -o jsonpath='{.clusters..server}')
kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-credentials system:konnectivity-server --client-certificate konnectivity.crt --client-key konnectivity.key --embed-certs=true
kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-cluster kubernetes --server "$SERVER" --certificate-authority /etc/kubernetes/pki/ca.crt --embed-certs=true
kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config set-context system:konnectivity-server@kubernetes --cluster kubernetes --user system:konnectivity-server
kubectl --kubeconfig /etc/kubernetes/konnectivity-server.conf config use-context system:konnectivity-server@kubernetes
rm -f konnectivity.crt konnectivity.key konnectivity.csr
다음으로 Konnectivity 서버와 에이전트를 배포해야 해요. kubernetes-sigs/apiserver-network-proxy가 참조 구현이에요.
제어 플레인 노드에 Konnectivity 서버를 배포해요. 제공된 konnectivity-server.yaml 매니페스트는 쿠버네티스 컴포넌트가 클러스터에서 정적 파드로 배포된다고 가정해요. 그렇지 않으면 Konnectivity 서버를 DaemonSet으로 배포할 수 있어요.
apiVersion: v1
kind: Pod
metadata:
name: konnectivity-server
namespace: kube-system
spec:
priorityClassName: system-cluster-critical
hostNetwork: true
containers:
- name: konnectivity-server-container
image: registry.k8s.io/kas-network-proxy/proxy-server:v0.0.37
command: ["/proxy-server"]
args: [
"--logtostderr=true",
# This needs to be consistent with the value set in egressSelectorConfiguration.
"--uds-name=/etc/kubernetes/konnectivity-server/konnectivity-server.socket",
"--delete-existing-uds-file",
# The following two lines assume the Konnectivity server is
# deployed on the same machine as the apiserver, and the certs and
# key of the API Server are at the specified location.
"--cluster-cert=/etc/kubernetes/pki/apiserver.crt",
"--cluster-key=/etc/kubernetes/pki/apiserver.key",
# This needs to be consistent with the value set in egressSelectorConfiguration.
"--mode=grpc",
"--server-port=0",
"--agent-port=8132",
"--admin-port=8133",
"--health-port=8134",
"--agent-namespace=kube-system",
"--agent-service-account=konnectivity-agent",
"--kubeconfig=/etc/kubernetes/konnectivity-server.conf",
"--authentication-audience=system:konnectivity-server"
]
livenessProbe:
httpGet:
scheme: HTTP
host: 127.0.0.1
port: 8134
path: /healthz
initialDelaySeconds: 30
timeoutSeconds: 60
ports:
- name: agentport
containerPort: 8132
hostPort: 8132
- name: adminport
containerPort: 8133
hostPort: 8133
- name: healthport
containerPort: 8134
hostPort: 8134
volumeMounts:
- name: k8s-certs
mountPath: /etc/kubernetes/pki
readOnly: true
- name: kubeconfig
mountPath: /etc/kubernetes/konnectivity-server.conf
readOnly: true
- name: konnectivity-uds
mountPath: /etc/kubernetes/konnectivity-server
readOnly: false
volumes:
- name: k8s-certs
hostPath:
path: /etc/kubernetes/pki
- name: kubeconfig
hostPath:
path: /etc/kubernetes/konnectivity-server.conf
type: FileOrCreate
- name: konnectivity-uds
hostPath:
path: /etc/kubernetes/konnectivity-server
type: DirectoryOrCreate
그런 다음 클러스터에 Konnectivity 에이전트를 배포해요:
apiVersion: apps/v1
# Alternatively, you can deploy the agents as Deployments. It is not necessary
# to have an agent on each node.
kind: DaemonSet
metadata:
labels:
addonmanager.kubernetes.io/mode: Reconcile
k8s-app: konnectivity-agent
namespace: kube-system
name: konnectivity-agent
spec:
selector:
matchLabels:
k8s-app: konnectivity-agent
template:
metadata:
labels:
k8s-app: konnectivity-agent
spec:
priorityClassName: system-cluster-critical
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"
containers:
- image: us.gcr.io/k8s-artifacts-prod/kas-network-proxy/proxy-agent:v0.0.37
name: konnectivity-agent
command: ["/proxy-agent"]
args: [
"--logtostderr=true",
"--ca-cert=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt",
# Since the konnectivity server runs with hostNetwork=true,
# this is the IP address of the master machine.
"--proxy-server-host=35.225.206.7",
"--proxy-server-port=8132",
"--admin-server-port=8133",
"--health-server-port=8134",
"--service-account-token-path=/var/run/secrets/tokens/konnectivity-agent-token"
]
volumeMounts:
- mountPath: /var/run/secrets/tokens
name: konnectivity-agent-token
livenessProbe:
httpGet:
port: 8134
path: /healthz
initialDelaySeconds: 15
timeoutSeconds: 15
serviceAccountName: konnectivity-agent
volumes:
- name: konnectivity-agent-token
projected:
sources:
- serviceAccountToken:
path: konnectivity-agent-token
audience: system:konnectivity-server
마지막으로 클러스터에서 RBAC가 활성화되어 있다면 관련 RBAC 규칙을 만드세요:
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: system:konnectivity-server
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:auth-delegator
subjects:
- apiGroup: rbac.authorization.k8s.io
kind: User
name: system:konnectivity-server
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: konnectivity-agent
namespace: kube-system
labels:
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
더 알아보기 (Learn more)
- apiserver-network-proxy 참조 구현