Configuration as Code.

Write code

Use the expressivity of ECMAScript, the world's largest software ecosystem and the speed of v8 to build, organize and maintain configuration.

Generate configuration

jk generates all your JSON, YAML and arbitrary text configuration files. With a little luck, you will not have to touch a YAML file again. Ever.

Write JavaScript objects

Generate YAML (or JSON, plain text, ...)

  • // Alice is a developer.
const alice = {
  name: 'Alice',
  beverage: 'Club-Mate',
  monitors: 2,
  languages: [
    'python',
    'haskell',
    'c++',
    '68k assembly', // Alice is cool like that!
  ],
};

// Instruct to write the alice object as a YAML file.
export default [
  { value: alice, file: `developers/${alice.name.toLowerCase()}.yaml` },
];
  • beverage: Club-Mate
languages:
- python
- haskell
- c++
- 68k assembly
monitors: 2
name: Alice

Write high-level microservice definitions

Generate their Kubernetes configuration

  • import { MicroService } from './micro-service';

const billing = {
  name: 'billing',
  description: 'Provides the /api/billing endpoints for frontend.',
  maintainer: 'damien@weave.works',
  namespace: 'billing',
  port: 80,
  image: 'quay.io/acmecorp/billing:master-fd986f62',
  ingress: {
    path: '/api/billing',
  },
  dashboards: [
    'service.RPS.HTTP',
  ],
  alerts: [
    'service.RPS.HTTP.HighErrorRate',
  ],
};

export default MicroService(billing);
  • apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: billing
    maintainer: damien@weave.works
  name: billing
  namespace: billing
spec:
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: billing
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: billing
        maintainer: damien@weave.works
    spec:
      containers:
      - image: quay.io/acmecorp/billing:master-fd986f62
        name: billing
        ports:
        - containerPort: 80
  • apiVersion: v1
kind: Service
metadata:
  labels:
    app: billing
    maintainer: damien@weave.works
  name: billing
  namespace: billing
spec:
  ports:
  - port: 80
  selector:
    app: billing
  • apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
  labels:
    app: billing
    maintainer: damien@weave.works
  name: billing
  namespace: billing
spec:
  rules:
  - http:
      paths:
      - backend:
          serviceName: billing
          servicePort: 80
        path: /api/billing
  • apiVersion: v1
data:
  dashboard: '[{"annotations":{"list":[]},"editable":false,"gnetId":null,"graphTooltip":0,"hideControls":false,"id":null,"links":[],"panels":[{"aliasColors":{},"bars":false,"dashLength":10,"dashes":false,"dataSource":"$PROMETHEUS_DS","datasource":null,"fill":1,"gridPos":{"h":7,"w":12,"x":0,"y":0},"id":2,"legend":{"alignAsTable":false,"avg":false,"current":false,"max":false,"min":false,"rightSide":false,"show":true,"total":false,"values":false},"lines":true,"linewidth":1,"links":[],"nullPointMode":"null","percentage":false,"pointradius":5,"points":false,"renderer":"flot","repeat":null,"seriesOverrides":[],"spaceLength":10,"stack":false,"steppedLine":false,"targets":[{"expr":"sum
    by (code)(sum(irate(http_requests_total{job=''billing''}[2m])))","format":"time_series","intervalFactor":2,"legendFormat":"{{code}}","refId":"A"}],"thresholds":[],"title":"billing
    RPS","tooltip":{"shared":true,"sort":0,"value_type":"individual"},"type":"graph","xaxis":{"buckets":null,"mode":"time","name":null,"show":true},"yaxis":[{"format":"short","label":null,"logBase":1,"max":null,"min":null,"show":true},{"format":"short","label":null,"logBase":1,"max":null,"min":null,"show":true}]},{"aliasColors":{},"bars":false,"dashLength":10,"dashes":false,"dataSource":"$PROMETHEUS_DS","datasource":null,"fill":1,"gridPos":{"h":7,"w":12,"x":12,"y":0},"id":3,"legend":{"alignAsTable":false,"avg":false,"current":false,"max":false,"min":false,"rightSide":false,"show":true,"total":false,"values":false},"lines":true,"linewidth":1,"links":[],"nullPointMode":"null","percentage":false,"pointradius":5,"points":false,"renderer":"flot","repeat":null,"seriesOverrides":[],"spaceLength":10,"stack":false,"steppedLine":false,"targets":[{"expr":"histogram_quantile(0.99,
    sum(rate(http_request_duration_seconds_bucket{job=''billing''}[2m])) by (route)
    * 1e3","format":"time_series","intervalFactor":2,"legendFormat":"99th percentile","refId":"A"},{"expr":"histogram_quantile(0.50,
    sum(rate(http_request_duration_seconds_bucket{job=''billing''}[2m])) by (route)
    * 1e3","format":"time_series","intervalFactor":2,"legendFormat":"median","refId":"B"},{"expr":"sum(rate(http_request_total{job=''billing''}[2m]))
    / sum(rate(http_request_duration_seconds_count{job=''billing''}[2m])) * 1e3","format":"time_series","intervalFactor":2,"legendFormat":"mean","refId":"C"}],"thresholds":[],"title":"billing
    Latency","tooltip":{"shared":true,"sort":0,"value_type":"individual"},"type":"graph","xaxis":{"buckets":null,"mode":"time","name":null,"show":true},"yAxis":[{"format":"ms","label":null,"logBase":1,"max":null,"min":null,"show":true},{"format":"short","label":null,"logBase":1,"max":null,"min":null,"show":true}],"yaxis":[{"format":"short","label":null,"logBase":1,"max":null,"min":null,"show":true},{"format":"short","label":null,"logBase":1,"max":null,"min":null,"show":true}]}],"refresh":"","schemaVersion":16,"style":"dark","tags":[],"templating":{"list":[]},"time":{"from":"now-6h","to":"now"},"timepicker":{"refresh_intervals":["5s","10s","30s","1m","5m","15m","30m","1h","2h","1d"],"time_options":["5m","15m","1h","6h","12h","24h","2d","7d","30d"]},"timezone":"browser","title":"Service
    > billing","uid":"","version":0}]'
kind: ConfigMap
metadata:
  labels:
    app: billing
    maintainer: damien@weave.works
  name: billing-dashboards
  namespace: billing
  • apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    app: billing
    maintainer: damien@weave.works
    prometheus: global
    role: alert-rules
  name: billing
spec:
  groups:
  - name: billing-alerts.rules
    rules:
    - alert: HighErrorRate
      annotations:
        description: More than 10% of requests to the billing service are failing
          with 5xx errors
        details: '{{$value | printf "%.1f"}}% errors for more than 5m'
        service: billing
      expr: |-
        rate(http_request_total{job=billing,code=~"5.."}[2m])
            / rate(http_request_duration_seconds_count{job=billing}[2m]) * 100 > 10
      for: 5m
      labels:
        severity: critical
  • apiVersion: v1
kind: Namespace
metadata:
  name: billing