Kubernetes

Tools

cuelang

Kubernetes tutorial - cuelang - github

cuelang 算是下面這個 java 初學者對於分號問題的 JOSN 版本回應，忘記加單雙引號沒關係，人看的懂可以快速回應就好，尤其是一大包 yaml 設定要搞定的 kubernetes。

Today my 16yr old cousin asked me... "If the compiler knows that.. "semicolon is missing at line no 16 in Helloworld.java ", then why it can't simply put a ' ; ' there instead of telling us..."

tutorial kubernetes - cuelang - github 只要跑一次就大概知道用在哪裡，特別是設定檔很多的時候應該做有用，如果只有個位數引入 CUE 就要考慮多個工具的複雜度問題。

frontend/bartender

kubernetes 的佈署如果需要開服務需要另外寫，利用 cloud.cue 樣板加上目錄裡面的 kube.cue 可將下面常見的佈署模板變成只有一行。

$ cat ./frontend/bartender/kube.cue 
package kube

deployment bartender image: "gcr.io/myproj/bartender:v0.1.34"

生成

$ cue cmd dump ./frontend/bartender/
apiVersion: v1
kind: Service
metadata:
  labels:
    app: bartender
    component: frontend
    domain: prod
  name: bartender
spec:
  ports:
  - name: http
    port: 7080
    protocol: TCP
  selector:
    app: bartender
    component: frontend
    domain: prod
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  labels:
    component: frontend
  name: bartender
spec:
  replicas: 1
  template:
    metadata:
      annotations:
        prometheus.io.port: "7080"
        prometheus.io.scrape: "true"
      labels:
        app: bartender
        component: frontend
        domain: prod
    spec:
      containers:
      - args: []
        image: gcr.io/myproj/bartender:v0.1.34
        name: bartender
        ports:
        - containerPort: 7080
          name: http

proxy/nginx 範例

以 nginx 為例寫 223 行來設定，產出 yaml 設定檔為 260 行，如果是 json 達 612 行。

$ cd doc/tutorial/kubernetes/manual/services
$ find ./proxy/nginx/ | xargs wc
      0       0       0 ./proxy/nginx/
     19      38     337 ./proxy/nginx/kube.cue
      6      12     108 ./proxy/nginx/service.cue
    198     495    7683 ./proxy/nginx/configmap.cue
    223     545    8128 總計
$ cue cmd dump ./proxy/nginx/ | wc
    260     606    9074
$ cue eval ./proxy/nginx | wc
    612    1365   23358

cue 檔案雖是 json 的超集合，加上共用樣板可寫的比 yaml 精簡。

package kube

deployment nginx: {
	image: "nginx:1.11.10-alpine"

	expose port http:  80
	expose port https: 443

	volume "secret-volume": {
		mountPath: "/etc/ssl"
		spec secret secretName: "proxy-secrets"
	}

	volume "config-volume": {
		mountPath: "/etc/nginx/nginx.conf"
		subPath:   "nginx.conf"
		spec configMap name: "nginx"
	}
}

置入 MAD WHITE

FROM golang:1.13 AS build-cue
RUN go get -u cuelang.org/go/cmd/cue

FROM codercom/code-server:2.preview.11-vsc1.37.0
COPY --from=build-cue /go/bin/cue /usr/bin/cue

Examples

TODO

Vault

hashicorp/vault: A tool for secrets management, encryption as a service, and privileged access management

banzaicloud/bank-vaults: A Vault swiss-army knife: a K8s operator, Go client with automatic token renewal, automatic configuration, multiple unseal options and more. A CLI tool to init, unseal and configure Vault (auth methods, secret engines). Direct secret injection into Pods.

Prometheus

Prometheus

Grafana

Grafana Labs

201909