create-rc.sh

#! /bin/bash
_container=$1
cat > controller.yaml <<EOF
---
kind: ReplicationController
apiVersion: v1
metadata:
  name: some-app
spec:
  replicas: 1
  selector:
    app: some-app
  template:
    metadata:
      labels:
        app: some-app
    spec:
      containers:
      - name: some-app
        imagePullPolicy: Always
        image: $_image
EOF          

deploy.sh

#auth kubernetes
#check dependencies
_image="path-to-image:$_sha"
./create-rc.sh $_image
kubectl get rc some-app > /dev/null 2>&1;
if [ $? -ne 0 ]; then
  echo "Replication controller does not exist, creating.";
  kubectl create -f controller.yaml;
else
  echo "Updating rc and performing rolling update";
  kubectl apply -f controller.yaml;
  sleep 2;
  kubectl rolling-update some-app --image=$_image --update-period=30s --timeout=1m30s;
  if [ $? -ne 0 ]; then
    echo "Could not perform rolling update"
    exit 1;
  fi;
fi