rdc-lda / k8s-wait-for

A simple script that allows to wait for a k8s service, job or pods to enter a desired state

k8s-wait-for

A simple script that allows waiting for a k8s service, job or pods to enter the desired state.

Thanks to Michal Orzechowski for writing this amazing script - it has been modified to support multiple platforms.

Running

You can start simple. Run it on your cluster in a namespace you already have something deployed:

# For arm64 platform
kubectl run --generator=run-pod/v1 k8s-wait-for --rm -it --image rdcla/k8s-wait-for:latest --restart Never --command /bin/sh

Read --help and play with it!

/ > wait_for.sh -h
This script waits until a job, pod or service enter a ready state. 

wait_for.sh job [<job name> | -l<kubectl selector>]
wait_for.sh pod [<pod name> | -l<kubectl selector>]
wait_for.sh service [<service name> | -l<kubectl selector>]

Examples:
Wait for all pods with a following label to enter 'Ready' state:
wait_for.sh pod -lapp=develop-volume-gluster-krakow

Wait for all pods with a following label to enter 'Ready' or 'Error' state:
wait_for.sh pod-we -lapp=develop-volume-gluster-krakow

Wait for all the pods in that job to have a 'Succeeded' state:
wait_for.sh job develop-volume-s3-krakow-init

Wait for all the pods in that job to have a 'Succeeded' or 'Failed' state:
wait_for.sh job-we develop-volume-s3-krakow-init

Wait for all selected pods to enter the 'Ready' state:
wait_for.sh pod -l"release in (develop), chart notin (cross-support-job-3p)"

Example

A complex Kubernetes deployment manifest (generated by helm). This deployment waits for one job to finish and 2 pods to enter a ready state.

kind: StatefulSet
metadata:
  name: develop-oneprovider-krakow
  labels:
    app: develop-oneprovider-krakow
    chart: oneprovider-krakow
    release: develop
    heritage: Tiller
    component: oneprovider
  annotations:
    version: "0.2.17"
spec:
  selector:
    matchLabels:
      app: develop-oneprovider-krakow
      chart: oneprovider-krakow
      release: develop
      heritage: Tiller
      component: "oneprovider"
  serviceName: develop-oneprovider-krakow
  template:
    metadata:
      labels:
        app: develop-oneprovider-krakow
        chart: oneprovider-krakow
        release: develop
        heritage: Tiller
        component: "oneprovider"
      annotations:
        version: "0.2.17"
    spec:
      initContainers:
        - name: wait-for-onezone
          image: groundnuty/k8s-wait-for:v1.3
          imagePullPolicy: Always
          args:
            - "job"
            - "develop-onezone-ready-check"
        - name: wait-for-volume-ceph
          image: groundnuty/k8s-wait-for:v1.3
          imagePullPolicy: Always
          args:
            - "pod"
            - "-lapp=develop-volume-ceph-krakow"
        - name: wait-for-volume-gluster
          image: groundnuty/k8s-wait-for:v1.3
          imagePullPolicy: Always
          args:
            - "pod"
            - "-lapp=develop-volume-gluster-krakow"
      containers:
      - name: oneprovider
        image: docker.onedata.org/oneprovider:ID-a3a9ff0d78
        imagePullPolicy: Always