Check your Kubernetes deployments! https://medium.com/polarsquad/check-your-kubernetes-deployments-46dbfbc47a7c

deploy.md

#!/bin/sh
#
# This script deploys the given manifest,
# tracks the deployment, and rolls back on failure.
#
# First execute this with "myapp.yaml" and then try it with "myapp.failing.yaml"
#

MANIFEST_PATH=$1
DEPLOYMENT_NAME=myapp

if [ -n "$2" ]; then
    DEPLOYMENT_NAME=$2
fi

kubectl apply -f "$MANIFEST_PATH"
if ! kubectl rollout status deployment "$DEPLOYMENT_NAME"; then
    echo "Rolling back deployment!" >&2
    kubectl rollout undo deployment "$DEPLOYMENT_NAME"
    kubectl rollout status deployment myapp
    exit 1
fi

myapp.failing.yaml

# Example hello world app deployment that fails
# because of an incorrectly configured readiness probe.
#
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  replicas: 3
  progressDeadlineSeconds: 30
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 0
      maxSurge: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - image: polarsquad/hello-world-app:master
        name: hello-world
        ports:
        - containerPort: 3000
        readinessProbe:
          httpGet:
            path: /this-does-not-exist
            port: 3000

myapp.yaml

# Example hello world app deployment
# including a readiness probe and a progress deadline.
#
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: myapp
  name: myapp
spec:
  replicas: 3
  progressDeadlineSeconds: 30
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 0
      maxSurge: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - image: polarsquad/hello-world-app:master
        name: hello-world
        ports:
        - containerPort: 3000
        readinessProbe:
          httpGet:
            path: /
            port: 3000