Question

我正在使用 GKE 和 Helm v3，我正在尝试使用 ComputeAddress 创建/保留静态 IP 地址，然后使用之前保留的 IP 地址创建 DNS A 记录。

预留 IP 地址

apiVersion: compute.cnrm.cloud.google.com/v1beta1
kind: ComputeAddress
metadata:
  name: ip-address
  annotations:
    cnrm.cloud.google.com/project-id: project-id
spec:
  location: global

获取预留IP地址

kubectl get computeaddress ip-address -o jsonpath='{.spec.address}'

创建 DNS A 记录

apiVersion: dns.cnrm.cloud.google.com/v1beta1
kind: DNSRecordSet
metadata:
  name: dns-record-a
  annotations:
    cnrm.cloud.google.com/project-id: project-id
spec:
  name: "{{ .Release.Name }}.example.com"
  type: "A"
  ttl: 300
  managedZoneRef:
    external: example-com
  rrdatas:
    - **IP-ADDRESS-VALUE** <----

有没有办法在 DNSRecordSet 资源中引用由 ComputeAddress 创建的 IP 地址值？

基本上，我需要类似于 Terraform 中的输出值。

谢谢！

Answer 1

目前，无法在字段“rrdatas”上分配不同的值作为字符串（IP 地址）。因此，您无法“调用”其他资源，例如之前创建的 IP 地址。您需要将值放在格式 x.x.x.x

Answer 2

有趣的是，GKE Ingress 存在类似的东西，我们可以使用注释引用保留的 IP 地址和托管 SSL 证书：

annotations:
  kubernetes.io/ingress.global-static-ip-name: my-static-address

我不知道为什么 DNSRecordSet 资源没有这样的东西。希望 GKE 将来会推出它。

我没有运行两个命令，而是通过使用 Helm 的钩子找到了一种解决方法。

首先，我们需要将 Job 定义为 post-install 和 post-upgrade 钩子，它们将在准备好时获取保留的 IP 地址，然后创建适当的 DNSRecordSet资源与它。检索 IP 地址的脚本和 DNSRecordSet 的清单通过 ConfigMap 传递并挂载到 Pod。

apiVersion: batch/v1
kind: Job
metadata:
  name: "{{ .Release.Name }}-dns-record-set-hook"
  annotations:
    # This is what defines this resource as a hook. Without this line, the
    # job is considered part of the release.
    "helm.sh/hook": post-install,post-upgrade
    "helm.sh/hook-delete-policy": before-hook-creation,hook-succeeded
spec:
  template:
    metadata:
      name: "{{ .Release.Name }}-dns-record-set-hook"
    spec:
      restartPolicy: OnFailure
      containers:
        - name: post-install-job
          image: alpine:latest
          command:  ['sh', '-c', '/opt/run-kubectl-command-to-set-dns.sh']
          volumeMounts:
            - name: volume-dns-record-scripts
              mountPath: /opt
            - name: volume-writable
              mountPath: /mnt
      volumes:
        - name: volume-dns-record-scripts
          configMap:
            name: dns-record-scripts
            defaultMode: 0777
        - name: volume-writable
          emptyDir: {}

带有脚本和清单文件的 ConfigMap 定义：

apiVersion: v1
kind: ConfigMap
metadata:
  creationTimestamp: null
  name: dns-record-scripts
data:
  run-kubectl-command-to-set-dns.sh: |-
    # install kubectl command
    apk add curl && \
    curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.15.1/bin/linux/amd64/kubectl && \
    chmod u+x kubectl && \
    mv kubectl /bin/kubectl

    # wait for reserved IP address to be ready
    kubectl wait --for=condition=Ready computeaddress/ip-address

    # get reserved IP address
    IP_ADDRESS=$(kubectl get computeaddress ip-address -o jsonpath='{.spec.address}')

    echo "Reserved address: $IP_ADDRESS"
  
    # update IP_ADDRESS in manifest
    sed "s/##IP_ADDRESS##/$IP_ADDRESS/g" /opt/dns-record.yml > /mnt/dns-record.yml
  
    # create DNS record
    kubectl apply -f /mnt/dns-record.yml

  dns-record.yml: |-
    apiVersion: dns.cnrm.cloud.google.com/v1beta1
    kind: DNSRecordSet
    metadata:
      name: dns-record-a
      annotations:
        cnrm.cloud.google.com/project-id: project-id
    spec:
      name: "{{ .Release.Name }}.example.com"
      type: A
      ttl: 300
      managedZoneRef:
        external: example-com
      rrdatas:
        - "##IP_ADDRESS##"

最后，为了（默认）服务帐户能够检索 IP 地址并创建/更新 DNSRecordSet，我们需要为其分配一些角色：

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: dnsrecord-setter
rules:
  - apiGroups: ["compute.cnrm.cloud.google.com"]
    resources: ["computeaddresses"]
    verbs: ["get", "list"]
  - apiGroups: ["dns.cnrm.cloud.google.com"]
    resources: ["dnsrecordsets"]
    verbs: ["get", "create", "patch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: dnsrecord-setter
subjects:
  - kind: ServiceAccount
    name: default
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: dnsrecord-setter

定义另一个资源时如何从一个 Kubernetes 资源引用值

2 个答案: