是否可以在 Kubernetes 中启动自签名 Docker 注册表并让其他服务使用它作为注册表来获取其映像？

Question

问题陈述

我想提供一个私有注册表，其中捆绑了我的产品所需的所有图像（是的，它将是胖图像，但我可以接受）
我会以某种方式手动上传这张图片
我会运行 docker 私有注册表作为 Kubernetes 中的一项服务（可能在某些名称空间中）
当其他services/deployments（与registry在同一个命名空间）发生在Kubernetes中时，他们应该使用一致的名称引用这个registry

约束

我们希望注册表只暴露给集群而不是外部
我们想使用自签名证书而不是由 CA 签名

我遵循了这些链接中的一些说明（不知道这样做是否正确）

创建通过 Kubernetes 签名的证书

创建 server.key
创建一个csr.info

[ req ]
default_bits = 2048
prompt = no
default_md = sha256
req_extensions = req_ext
distinguished_name = dn

[ dn ]
C = US
ST = oh
L = cincinnati
O = engg
OU = prod
CN = prateek.svc.cluster.local

[ req_ext ]
subjectAltName = @alt_names

[ alt_names ]
DNS.1 = registry.prateek.svc.cluster.local

[ v3_ext ]
authorityKeyIdentifier=keyid,issuer:always
basicConstraints=CA:FALSE
keyUsage=keyEncipherment,dataEncipherment
extendedKeyUsage=serverAuth,clientAuth
subjectAltName=@alt_names

创建了 server.csr (openssl req -new -key server.key -out server.csr -config csr.conf)
在K8s中创建CertificateSigningRequest

cat <<EOF | kubectl apply -f -
apiVersion: certificates.k8s.io/v1beta1
kind: CertificateSigningRequest
metadata:
name: registry.prateek
spec:
groups:
- system:authenticated
request: $(cat server.csr | base64 | tr -d '\n')
usages:
- digital signature
- key encipherment
- server auth
EOF

检查 CSR 是否存在

kubectl describe csr registry.prateek
Name: registry.prateek
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"certificates.k8s.io/v1beta1","kind":"CertificateSigningRequest","metadata":{"annotations":{},"name":"registry.prateek","namespace":""},"spec":{"groups":["system:authenticated"],"request":"LS0sdfsfsdsfd=","usages":["digital signature","key encipherment","server auth"]}}

CreationTimestamp: Thu, 11 Apr 2019 11:15:42 -0400
Requesting User: docker-for-desktop
Status: Pending
Subject:
Common Name: prateek.svc.cluster.local
Serial Number:
Organization: engg
Organizational Unit: prod
Country: US
Locality: cincinnati
Province: oh
Subject Alternative Names:
DNS Names: registry.prateek.svc.cluster.local
Events: <none>

批准了 CSR：kubectl certificate approve registry.prateek

启动注册表内部服务

为种类添加了证书和密钥：Secret

注册表-secret.yml

apiVersion: v1
kind: Secret
metadata:
  name: registry-credentials
data:
  certificate: <CERTIFICATE in base64>
  key: <KEY in base64>

创建注册表部署和服务（使用这些秘密）注册表-deployment.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: registry
  namespace: prateek
  labels:
      app: registry
spec:
  replicas: 1
  selector:
    matchLabels:
      app: registry
  template:
    metadata:
      labels:
        app: registry
    spec:
      containers:
        - name: registry
          image: prateek/registry
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 443
          env:
            - name: REGISTRY_HTTP_ADDR
              value: "0.0.0.0:443"
            - name: REGISTRY_HTTP_TLS_CERTIFICATE
              value: "/certs/certificate"
            - name: REGISTRY_HTTP_TLS_KEY
              value: "/certs/key"
          volumeMounts:
            - name: cert-files
              mountPath: /certs
      volumes:
        - name: cert-files
          secret:
            secretName: registry-credentials

注册表-service.yml

apiVersion: v1
kind: Service
metadata:
  name: registry
  namespace: prateek
spec:
  selector:
    app: registry
  ports:
  - protocol: TCP
    port: 443
    targetPort: 443
  type: LoadBalancer

测试注册服务已启动

尝试通过测试容器访问注册表端点。我已经在 docker 中加载了这个测试舱的图像。

curl https://registry.prateek.svc.cluster.local/v2/_catalog -k
{"repositories":["prateek/echo"]}

使用注册表服务中的映像进行部署

尝试使用镜像部署：registry。prateek/prateek/echo:latest

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello
  namespace: cequence
  labels:
      app: hello
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        app: hello
    spec:
      containers:
      - name: hello
        image: registry.prateek/prateek/echo:latest
        imagePullPolicy: IfNotPresent
        ports:
         - containerPort: 5678
        args: ["-text=hello"]

部署给出错误

Normal Pulling 10s (x2 over 25s) kubelet, docker-for-desktop pulling image "registry.prateek/prateek/echo:latest"
Warning Failed 10s (x2 over 25s) kubelet, docker-for-desktop Failed to pull image "registry.prateek/prateek/echo:latest": rpc error: code = Unknown desc = Error response from daemon: Get https://registry.prateek/v2/: Service Unavailable

将部署更改为具有图像：registry.prateek.svc.cluster.local/prateek/echo:latest

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello
  namespace: cequence
  labels:
      app: hello
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        app: hello
    spec:
      containers:
      - name: hello
        image: registry.prateek.svc.cluster.local/prateek/echo:latest
        imagePullPolicy: IfNotPresent
        ports:
         - containerPort: 5678
        args: ["-text=hello"]

得到类似的错误

Warning Failed 1s kubelet, docker-for-desktop Failed to pull image "registry.prateek.svc.cluster.local/prateek/echo:latest": rpc error: code = Unknown desc = Error response from daemon: Get https://registry.prateek.svc.cluster.local/v2/: Service Unavailable

我什至不知道这是可能的。运行 docker 注册表作为服务，并指向命名空间中的其他服务以在集群中使用该注册表部署。欢迎任何建议

Answer 1

容器守护进程运行在 kubernetes 之外。

因此，如果你想拉取镜像，你需要确保registry可以从节点直接访问，而不是像服务一样使用kubernetes机制。（不像你在步骤9中通过pod测试的，你必须能够直接在节点上工作！）

通常的选择是创建一个 DNS 条目或 hosts.txt 条目以指向一个节点，其中通过 hostPort（容器）或 nodePort（服务）注册表是可访问或您使用适当的入口。

是否可以在 Kubernetes 中启动自签名 Docker 注册表并让其他服务使用它作为注册表来获取其映像？

Is it possible to start Self-Signed Docker Registry in Kubernetes and have other service use that as the registry to get its image?

docker

kubernetes

kubectl

docker-registry

kubelet