Devops

Containerizing scala backend

1. Logged in kops.<domain>.com as superuser (sudo su)

2. cd /home/ubuntu/tf_files/cootbackend

3. Used the Dockerfile in this location

4. We need to definitely have the COPY <dir>-rest-services /<dir>-rest-services in the Dockerfile.

   Only then the image can have the resources we need to do the scala

5. Build the image:

   docker build -t <dockerhub registry name>/<bkend-scala-image-v0:v0 .

6. Run the image docker run -p 8091:8091 --name backend_service_v0 \ -it -v /home/ubuntu/tf_files:/tf_files <dockerhub registry name>/bkend-scala-image-v0:v0

   FRONT END
    docker build -t <dockerhub registry name>/-fend-react-image-v0:v0 .
    docker run -p 8080:80 --name _frontend_service_v0 \
        -it -v /home/ubuntu/tf_files:/tf_files <dockerhub registry name>/-fend-react-image-v0:v0
   
    # to run the container in detached mode and put the
    # CMD in the background, so that the xterm can be used
    # don't forget to open port 8080 as custom tcp port in AWS
    docker run -p 8080:80 --name _frontend_service_v0 -it -v /home/ubuntu:/home/ubuntu \
        -d <dockerhub registry name>/-fend-react-image-v0:v0

   Get a bash in docker VM docker exec -it f27eed929330 bash -c "export COLUMNS=tput cols; export LINES=tput lines; exec bash"

    Note: here the docker port 80(Right side) binds to host port 8080. Need to open port 8080 in AWS

Kubernetes

Horizontal pod autoscaling

Ref: https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#support-for-custom-metrics

HPA:
To setup HPA, first install metrics-server
Ref: https://github.com/kubernetes/kubernetes/issues/57996
        https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/metrics-server
        https://github.com/kubernetes-incubator/metrics-server
To get HPA metrics to start working
git clone https://github.com/kubernetes-incubator/metrics-server.git
cd metrics_server/metrics-server
kubectl create -f deploy/1.8+/