Kubernetes Wait

A simple hixdev/k8sws alpine-based docker image with a single curl dependency, and an sh function k8sw8 that can be used inside K8S' initContainers for a Deployment to wait for other Deployments.

Usage

Imagine having two K8S Deployments.

First Deployment - API

We have a simple API that exposes /health endpoint - whenever API is ready, it responds with HTTP 200.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: api
spec:
  template:
    spec:
      containers:
        - name: api
          image: example/api:0.0.0

Second Deployment - WWW

We have a frontend WWW app, that needs the API to build its static pages during Deployment's spinoff.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: www
spec:
  template:
    spec:
      initContainers:
        - name: api-w8
          image: hixdev/k8sw8:latest
          env:
            ## Required
            - name: WAIT_URL
              value: http://api:3000/health
            ## Optional
            - name: WAIT_CODE
              value: "204"
            - name: WAIT_TIME
              value: "15"
            - name: GROUP_ID
              value: "10001"
            - name: GROUP_NAME
              value: "k9sw9"
            - name: USER_ID
              value: "10002"
            - name: USER_ID
              value: "k9sw9"
          securityContext:
            runAsUser: 10002
            runAsGroup: 10001
      containers:
        - name: www
          image: example/www:0.0.0
          command:
            - /bin/sh
          args:
            - -cx
            - |
              npm run build
              npm run start

Deployment

Do the following:

1. Run docker login as hixdev to https://hub.docker.com
2. Run ./publish x.y.z.