基于 Docker for MAC 的 Kubernetes 本地环境搭建与应用部署

基于 Docker for MAC 的 Kubernetes 本地环境搭建与应用部署归纳于分布式容器与编排，参考了 Docker + Kubernetes一文，更多 Docker 或者 Kubernetes 相关资料参阅 Awesome Reference。

基于 Docker for MAC 的 Kubernetes 本地环境搭建与应用部署

下载最新的 Docker for Mac 或者 Edge 版本，即可以看到内置的 Kubernetes 集群，直接点击安装即可在本地搭建好单节点的 Kubernetes 环境：

安装完毕后，如果我们也勾选了 Show system containers 选项，那么使用如下的 Docker 命令，能看到自动安装的 Kubernetes 相关容器：

➜  ~ docker container ls --format "table{{.Names}}\t{{.Image }}\t{{.Command}}"
NAMES                                                                                                                   IMAGE                                                    COMMAND
k8s_compose_compose-75f8bb4779-stxv9_docker_3c963862-f9f4-11e7-93cc-025000000001_0                                      docker/kube-compose-controller                           "/compose-controller…"
k8s_POD_compose-75f8bb4779-stxv9_docker_3c963862-f9f4-11e7-93cc-025000000001_0                                          gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_sidecar_kube-dns-545bc4bfd4-799pr_kube-system_139bf000-f9f4-11e7-93cc-025000000001_0                                gcr.io/google_containers/k8s-dns-sidecar-amd64           "/sidecar --v=2 --lo…"
k8s_dnsmasq_kube-dns-545bc4bfd4-799pr_kube-system_139bf000-f9f4-11e7-93cc-025000000001_0                                gcr.io/google_containers/k8s-dns-dnsmasq-nanny-amd64     "/dnsmasq-nanny -v=2…"
k8s_kubedns_kube-dns-545bc4bfd4-799pr_kube-system_139bf000-f9f4-11e7-93cc-025000000001_0                                gcr.io/google_containers/k8s-dns-kube-dns-amd64          "/kube-dns --domain=…"
k8s_kube-proxy_kube-proxy-rrd8t_kube-system_139b00df-f9f4-11e7-93cc-025000000001_0                                      gcr.io/google_containers/kube-proxy-amd64                "/usr/local/bin/kube…"
k8s_POD_kube-dns-545bc4bfd4-799pr_kube-system_139bf000-f9f4-11e7-93cc-025000000001_0                                    gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_POD_kube-proxy-rrd8t_kube-system_139b00df-f9f4-11e7-93cc-025000000001_0                                             gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_kube-scheduler_kube-scheduler-docker-for-desktop_kube-system_972d74c9fc2f4ebd8ab673058e386a65_0                     gcr.io/google_containers/kube-scheduler-amd64            "kube-scheduler --ad…"
k8s_kube-apiserver_kube-apiserver-docker-for-desktop_kube-system_f7a81e8fe624bd46059fc6084e86bb81_0                     gcr.io/google_containers/kube-apiserver-amd64            "kube-apiserver --ad…"
k8s_etcd_etcd-docker-for-desktop_kube-system_56a21c0a5f545c0cca5388c457bb1b3b_0                                         gcr.io/google_containers/etcd-amd64                      "etcd --advertise-cl…"
k8s_kube-controller-manager_kube-controller-manager-docker-for-desktop_kube-system_8d1848c1e562e35a225e402988eadcd1_0   gcr.io/google_containers/kube-controller-manager-amd64   "kube-controller-man…"
k8s_POD_kube-apiserver-docker-for-desktop_kube-system_f7a81e8fe624bd46059fc6084e86bb81_0                                gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_POD_kube-controller-manager-docker-for-desktop_kube-system_8d1848c1e562e35a225e402988eadcd1_0                       gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_POD_kube-scheduler-docker-for-desktop_kube-system_972d74c9fc2f4ebd8ab673058e386a65_0                                gcr.io/google_containers/pause-amd64:3.0                 "/pause"
k8s_POD_etcd-docker-for-desktop_kube-system_56a21c0a5f545c0cca5388c457bb1b3b_0                                          gcr.io/google_containers/pause-amd64:3.0                 "/pause"

关于各个容器的作用，可以参阅 这里。在安装过程中，Docker 也为我们安装了 kubectl 控制命令：

$ kubectl get namespaces
$ kubectl get posts --namespace kube-system

接下来我们可以使用 kubectl 命令来创建简单的 kubernetes-dashboard 服务：

➜  ~ kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml
secret "kubernetes-dashboard-certs" created
serviceaccount "kubernetes-dashboard" created
role "kubernetes-dashboard-minimal" created
rolebinding "kubernetes-dashboard-minimal" created
deployment "kubernetes-dashboard" created
service "kubernetes-dashboard" created

服务安装完毕后可以查看部署的容器与服务：

➜  ~ kubectl get deployments --namespace kube-system
NAME                   DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kube-dns               1         1         1            1           22m
kubernetes-dashboard   1         1         1            0           26s
➜  ~ kubectl get services --namespace kube-system
NAME                   TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
kube-dns               ClusterIP   10.96.0.10      <none>        53/UDP,53/TCP   22m
kubernetes-dashboard   ClusterIP   10.111.242.95   <none>        443/TCP         30s

在 Dashboard 启动完毕后，可以使用 kubectl 提供的 Proxy 服务来访问该面板：

$ kubectl proxy

# 打开如下地址：
# http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/

如果访问报错，可以尝试编辑 kubernetes-dashboard 服务，或者参阅这里：

$ kubectl -n kube-system edit service kubernetes-dashboard

# Please edit the object below. Lines beginning with a '#' will be ignored,
# and an empty file will abort the edit. If an error occurs while saving this file will be
# reopened with the relevant failures.
#
apiVersion: v1
...
  name: kubernetes-dashboard
  namespace: kube-system
  resourceVersion: "343478"
  selfLink: /api/v1/namespaces/kube-system/services/kubernetes-dashboard-head
  uid: 8e48f478-993d-11e7-87e0-901b0e532516
spec:
  clusterIP: 10.100.124.90
  externalTrafficPolicy: Cluster
  ports:
  - port: 443
    protocol: TCP
    targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard
  sessionAffinity: None
  type: ClusterIP ->> NodePort
status:
  loadBalancer: {}

访问上述地址，我们可以看到登录界面：

此时可暂时直接跳过，进入到控制面板中：

Docker 同样为我们提供了简单的应用示范，可以直接使用如下的 Docker Compose 配置文件:

version: '3.3'

services:
  web:
    build: web
    image: dockerdemos/lab-web
    volumes:
     - "./web/static:/static"
    ports:
     - "80:80"

  words:
    build: words
    image: dockerdemos/lab-words
    deploy:
      replicas: 5
      endpoint_mode: dnsrr
      resources:
        limits:
          memory: 16M
        reservations:
          memory: 16M

  db:
    build: db
    image: dockerdemos/lab-db

然后使用 stack 命令创建应用栈：

$ docker stack deploy --compose-file stack.yml demo

Stack demo was created
Waiting for the stack to be stable and running...
 - Service web has one container running

应用栈创建完毕后，可以使用 kubectl 查看创建的 Pods:

$ kubectl get pods

NAME                     READY     STATUS    RESTARTS   AGE
db-7f99cc64b7-cbd9t      1/1       Running   0          2m
web-758c6998f8-tmxfm     1/1       Running   0          2m
words-54bf6c5d57-8bxc8   1/1       Running   0          2m
words-54bf6c5d57-dzxm8   1/1       Running   0          2m
words-54bf6c5d57-k2448   1/1       Running   0          2m
words-54bf6c5d57-mhh4p   1/1       Running   0          2m
words-54bf6c5d57-w2q82   1/1       Running   0          2m

也可以来查看部署的集群与服务：

$ kubectl get deployments
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
db        1         1         1            1           3m
web       1         1         1            1           3m
words     5         5         5            5           3m

$ kubectl get services
NAME         TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
db           ClusterIP      None           <none>        55555/TCP      3m
kubernetes   ClusterIP      10.96.0.1      <none>        443/TCP        52m
web          LoadBalancer   10.97.154.28   <pending>     80:30577/TCP   3m
words        ClusterIP      None           <none>        55555/TCP      3m

可以看到这里的 web 有所谓的 LoadBalancer 类型，即可以对外提供服务。最后我们还可以用 stack 与 kubectl 命令来删除应用：

$ docker stack remove demo
$ kubectl delete deployment kubernetes-dashboard --namespace kube-system