出品丨Docker公司（ID：docker-cn）
編譯丨小東
每周一、三、五，與您不見不散！
随着單片系統變得越來越龐大以至于無法處理，許多企業開始将其分解為微服務體系結構。無論何時我們從單片架構轉向微服務架構，應用程式都包含多個元件，這些元件之間的服務需要進行互相通信。每個元件都有自己的資源，可以單獨擴充。如果我們談論 Kubernetes，它會變得非常複雜，除了需要管理版本數量之外，還需要處理所有對象，例如 ConfigMaps、services、pods 以及 Persistent Volumes。 可能會出現以下挑戰：
- 管理、編輯和更新多個 k8s 配置；
- 将多個 K8s 配置部署為單個應用程式；
- 共享和重用 K8s 配置和應用程式；
- 參數化并支援多個環境；
- 管理應用程式版本：rollout、rollback、diff、history；
- 定義部署生命周期（将在不同階段運作的控制操作）；
- 部署後驗證釋出狀态；
這些都可以通過 Kubernetes Helm 來管理，它提供了一種簡單的方法來将所有東西打包到一個簡單的應用程式中，并突出顯示您可以配置的内容。
Helm 是 Kubernetes 的部署管理（不僅僅是包管理器）。它對可重複部署、依賴項管理(重用和共享)、多配置管理、更新、復原和測試應用程式部署（版本）等方面做了大量工作。
今天，我們将在 Play with Kubernetes 平台上嘗試使用 Helm。
首先，打開
https://labs.play-with-k8s.com/通路 Kubernetes Playground。
點選“Login”按鈕以使用 Docker Hub 或 GitHub ID 進行身份驗證。
一旦開始會話，您将擁有一個自己的實驗室環境。
添加第一個 Kubernetes 節點
單擊左側的“Add New Instance” 來建您的第一個 Kubernetes 叢集節點。它會自動将其命名為“node1”。每個執行個體都預裝了Docker Community Edition（CE）和Kubeadm。該節點将被視為我們群集的主節點。
引導主節點
您可以通過使用以下腳本初始化主節點（node1）來引導 Kubernetes 叢集。将此腳本内容複制到 bootstrap.sh 檔案中，并使用“chmod + x bootstrap.sh”指令使其可執行。
當您執行此腳本時，作為初始化的一部分，kubeadm 将會編寫所需的幾個配置檔案，設定 RBAC 并部署Kubernetes控制平面元件（如 kube-apiserver、kube-dns、kube-proxy 和 etcd等等）。控制平面元件以 Docker 容器的形式進行部署。
複制上面的 kubeadm 連接配接令牌指令，并将其儲存以供下一步使用。此指令将用于将其他節點連接配接到叢集。
添加工作節點
點選“Add New Node”來添加一個新的工作節點。
檢查叢集狀态
[node1 ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
node1 Ready master 18m v1.11.3
node2 Ready 4m v1.11.3
node3 Ready 39s v1.11.3
node4 NotReady 22s v1.11.3
node5 NotReady 4s v1.11.3
[node1 ~]$
[node1 ]$ kubectl get po
No resources found.
[node1 ]$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 443/TCP 1h
[node1]$ 驗證正在運作的 Pod
[node1 ~]$ kubectl get nodes -o json |
> jq ".items[] | {name:.metadata.name} + .status.capacity"
{
"name": "node1",
"cpu": "8",
"ephemeral-storage": "10Gi",
"hugepages-1Gi": "0",
"hugepages-2Mi": "0",
"memory": "32929612Ki",
"pods": "110"
}
{
"name": "node2",
"cpu": "8",
"ephemeral-storage": "10Gi",
"hugepages-1Gi": "0",
"hugepages-2Mi": "0",
"memory": "32929612Ki",
"pods": "110"
}
{
"name": "node3",
"cpu": "8",
"ephemeral-storage": "10Gi",
"hugepages-1Gi": "0",
"hugepages-2Mi": "0",
"memory": "32929612Ki",
"pods": "110"
}
{
"name": "node4",
"cpu": "8",
"ephemeral-storage": "10Gi",
"hugepages-1Gi": "0",
"hugepages-2Mi": "0",
"memory": "32929612Ki",
"pods": "110"
}
{
"name": "node5",
"cpu": "8",
"ephemeral-storage": "10Gi",
"hugepages-1Gi": "0",
"hugepages-2Mi": "0",
"memory": "32929612Ki",
"pods": "110"
}
安裝 OpenSSL
[node1 ~]$ yum install -y openssl
安裝 Helm
$ url https://raw.githubusercontent.com/helm/helm/master/scripts/get > get_helm.sh
$ chmod 700 get_helm.sh
$ ./get_helm.sh
[node1 ~]$ sh get_helm.sh
Downloading https://kubernetes-helm.storage.googleapis.com/helm-v2.11.0-linux-amd64.tar.gz
Preparing to install helm and tiller into /usr/local/bin
helm installed into /usr/local/bin/helm
tiller installed into /usr/local/bin/tiller
get_helm.sh: line 177: which: command not found
Run 'helm init' to configure helm.
[node1 ~]$ helm init
Creating /root/.helm
Creating /root/.helm/repository
Creating /root/.helm/repository/cache
Creating /root/.helm/repository/local
Creating /root/.helm/plugins
Creating /root/.helm/starters
Creating /root/.helm/cache/archive
Creating /root/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /root/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
To prevent this, run `helm init` with the --tiller-tls-verify flag.
For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation
Happy Helming
安裝 Prometheus
讓我們嘗試使用 Helm 在擁有 5 個節點 K8s 群集上安裝 Prometheus Stack。
首先，可以使用“helm search ”選項搜尋應用程式堆棧。
[node1 ~]$ helm search prometheus
NAME CHART VERSION APP VERSION DESCRIPTION
stable/prometheus 7.3.4 2.4.3 Prometheus is a monitoring system and time series database.
stable/prometheus-adapter v0.2.0 v0.2.1 A Helm chart for k8s prometheus adapter
stable/prometheus-blackbox-exporter 0.1.3 0.12.0 Prometheus Blackbox Exporter
stable/prometheus-cloudwatch-exporter 0.2.1 0.5.0 A Helm chart for prometheus cloudwatch-exporter
stable/prometheus-couchdb-exporter 0.1.0 1.0 A Helm chart to export the metrics from couchdb in Promet...
stable/prometheus-mysql-exporter 0.2.1 v0.11.0 A Helm chart for prometheus mysql exporter with cloudsqlp...
stable/prometheus-node-exporter 0.5.0 0.16.0 A Helm chart for prometheus node-exporter
stable/prometheus-operator 0.1.7 0.24.0 Provides easy monitoring definitions for Kubernetes servi...
stable/prometheus-postgres-exporter 0.5.0 0.4.6 A Helm chart for prometheus postgres-exporter
stable/prometheus-pushgateway 0.1.3 0.6.0 A Helm chart for prometheus pushgateway
stable/prometheus-rabbitmq-exporter 0.1.4 v0.28.0 Rabbitmq metrics exporter for prometheus
stable/prometheus-redis-exporter 0.3.2 0.21.1 Prometheus exporter for Redis metrics
stable/prometheus-to-sd 0.1.1 0.2.2 Scrape metrics stored in prometheus format and push them ...
stable/elasticsearch-exporter 0.4.0 1.0.2 Elasticsearch stats exporter for Prometheus
stable/karma 1.1.2 v0.14 A Helm chart for Karma - an UI for Prometheus Alertmanager
stable/stackdriver-exporter 0.0.4 0.5.1 Stackdriver exporter for Prometheus
stable/weave-cloud 0.3.0 1.1.0 Weave Cloud is a add-on to Kubernetes which provides Cont...
stable/kube-state-metrics 0.9.0 1.4.0 Install kube-state-metrics to generate and expose cluster...
stable/mariadb 5.2.2 10.1.36 Fast, reliable, scalable, and easy to use open-source rel...
[node1 ~]$
更新鏡像倉庫
[node1 ~]$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈ Happy Helming!⎈ $helm install stable/prometheus
出現錯誤提示：“default” is forbidden: User “system:serviceaccount:kube-system:default” cannot get namespaces in the namespace “default”
如何修複？
要解決該問題，您需要按照以下步驟操作：
kubectl --namespace kube-system create serviceaccount tiller
kubectl create clusterrolebinding tiller --clusterrole cluster-admin --serviceaccount=kube-system:tiller
helm init --service-account tiller --upgrade
Helm 清單
[node1 ~]$ helm list
NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
excited-elk 1 Sun Oct 28 10:00:02 2018 DEPLOYED prometheus-7.3.4 2.4.3 default
[node1 ~]$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈ Happy Helming!⎈
[node1 ~]$ helm install stable/prometheus
NAME: excited-elk
LAST DEPLOYED: Sun Oct 28 10:00:02 2018
NAMESPACE: default
STATUS: DEPLOYED
RESOURCES:
==> v1beta1/DaemonSet
NAME AGE
excited-elk-prometheus-node-exporter 1s
==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
excited-elk-prometheus-node-exporter-7bjqc 0/1 ContainerCreating 0 1s
excited-elk-prometheus-node-exporter-gbcd7 0/1 ContainerCreating 0 1s
excited-elk-prometheus-node-exporter-tk56q 0/1 ContainerCreating 0 1s
excited-elk-prometheus-node-exporter-tkk9b 0/1 ContainerCreating 0 1s
excited-elk-prometheus-alertmanager-68f4f57c97-wrfjz 0/2 Pending 0 1s
excited-elk-prometheus-kube-state-metrics-858d44dfdc-vt4wj 0/1 ContainerCreating 0 1s
excited-elk-prometheus-pushgateway-58bfd54d6d-m4n69 0/1 ContainerCreating 0 1s
excited-elk-prometheus-server-5958586794-b97xn 0/2 Pending 0 1s
==> v1/ConfigMap
NAME AGE
excited-elk-prometheus-alertmanager 1s
excited-elk-prometheus-server 1s
==> v1/ServiceAccount
excited-elk-prometheus-alertmanager 1s
excited-elk-prometheus-kube-state-metrics 1s
excited-elk-prometheus-node-exporter 1s
excited-elk-prometheus-pushgateway 1s
excited-elk-prometheus-server 1s
==> v1beta1/ClusterRole
excited-elk-prometheus-kube-state-metrics 1s
excited-elk-prometheus-server 1s
==> v1beta1/Deployment
excited-elk-prometheus-alertmanager 1s
excited-elk-prometheus-kube-state-metrics 1s
excited-elk-prometheus-pushgateway 1s
excited-elk-prometheus-server 1s
==> v1/PersistentVolumeClaim
excited-elk-prometheus-alertmanager 1s
excited-elk-prometheus-server 1s
==> v1beta1/ClusterRoleBinding
excited-elk-prometheus-kube-state-metrics 1s
excited-elk-prometheus-server 1s
==> v1/Service
excited-elk-prometheus-alertmanager 1s
excited-elk-prometheus-kube-state-metrics 1s
excited-elk-prometheus-node-exporter 1s
excited-elk-prometheus-pushgateway 1s
excited-elk-prometheus-server 1s
NOTES:
The Prometheus server can be accessed via port 80 on the following DNS name from within your cluster:
excited-elk-prometheus-server.default.svc.cluster.local
Get the Prometheus server URL by running these commands in the same shell:
export POD_NAME=$(kubectl get pods --namespace default -l "app=prometheus,component=server" -o jsonpath="{.items[0].metadata.name}")
kubectl --namespace default port-forward $POD_NAME 9090
The Prometheus alertmanager can be accessed via port 80 on the following DNS name from within your cluster:
excited-elk-prometheus-alertmanager.default.svc.cluster.local
Get the Alertmanager URL by running these commands in the same shell:
export POD_NAME=$(kubectl get pods --namespace default -l "app=prometheus,component=alertmanager" -o jsonpath="{.items[0].metadata.name}")
kubectl --namespace default port-forward $POD_NAME 9093
The Prometheus PushGateway can be accessed via port 9091 on the following DNS name from within your cluster:
excited-elk-prometheus-pushgateway.default.svc.cluster.local
Get the PushGateway URL by running these commands in the same shell:
export POD_NAME=$(kubectl get pods --namespace default -l "app=prometheus,component=pushgateway" -o jsonpath="{.items[0].metadata.name}")
kubectl --namespace default port-forward $POD_NAME 9091
For more information on running Prometheus, visit:
https://prometheus.io/
[node1 ~]$ kubectl get all
NAME READY STATUS RESTARTS AGE
pod/excited-elk-prometheus-alertmanager-68f4f57c97-wrfjz 0/2 Pending 0 3m
pod/excited-elk-prometheus-kube-state-metrics-858d44dfdc-vt4wj 1/1 Running 0 3m
pod/excited-elk-prometheus-node-exporter-7bjqc 1/1 Running 0 3m
pod/excited-elk-prometheus-node-exporter-gbcd7 1/1 Running 0 3m
pod/excited-elk-prometheus-node-exporter-tk56q 1/1 Running 0 3m
pod/excited-elk-prometheus-node-exporter-tkk9b 1/1 Running 0 3m
pod/excited-elk-prometheus-pushgateway-58bfd54d6d-m4n69 1/1 Running 0 3m
pod/excited-elk-prometheus-server-5958586794-b97xn 0/2 Pending 0 3m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/excited-elk-prometheus-alertmanager ClusterIP 10.106.159.46 80/TCP 3m
service/excited-elk-prometheus-kube-state-metrics ClusterIP None 80/TCP 3m
service/excited-elk-prometheus-node-exporter ClusterIP None 9100/TCP 3m
service/excited-elk-prometheus-pushgateway ClusterIP 10.106.88.15 9091/TCP 3m
service/excited-elk-prometheus-server ClusterIP 10.107.15.64 80/TCP 3m
service/kubernetes ClusterIP 10.96.0.1 443/TCP 37m
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/excited-elk-prometheus-node-exporter 4 4 4 4 4 3m
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.apps/excited-elk-prometheus-alertmanager 1 1 1 0 3m
deployment.apps/excited-elk-prometheus-kube-state-metrics 1 1 1 1 3m
deployment.apps/excited-elk-prometheus-pushgateway 1 1 1 1 3m
deployment.apps/excited-elk-prometheus-server 1 1 1 0 3m
NAME DESIRED CURRENT READY AGE
replicaset.apps/excited-elk-prometheus-alertmanager-68f4f57c97 1 1 0 3m
replicaset.apps/excited-elk-prometheus-kube-state-metrics-858d44dfdc 1 1 1 3m
replicaset.apps/excited-elk-prometheus-pushgateway-58bfd54d6d 1 1 1 3m
replicaset.apps/excited-elk-prometheus-server-5958586794 1 1 0 3m
[node1 ~]$
等待幾分鐘，您就可以使用
https://:9090通路 Prometheus UI了。
在下一篇 Kubernetes 實戰教學系列文章中，我将為您帶來更多關于 Helm on PWD Playground 的有趣内容。