kubernetes

Overview

OpenEMR Kubernetes orchestration. Creates 2 instances of OpenEMR with 1 instance of MariaDB, Redis, and phpMyAdmin. Would not consider it production quality, but will be a good working, starting point, and hopefully open the door to a myriad of other kubernetes based solutions. Note this is supported by 6.0.0 docker. If wish to use the most recent codebase rather than 6.0.0 docker, then can change from openemr/openemr:6.0.0 to openemr/openemr:flex in the openemr-deployment.yaml script (note this will take much longer to start up (probably at least 10 minutes and up to 90 minutes) and is more cpu intensive since each instance of OpenEMR will download codebase and build separately).

(Quick note: Development in progress, minikube not required for deployment. :8080 for http, :8090 for https, grab the NodePort for phpmyadmin)

Use

1. Install (and then start) Kubernetes with Minikube: https://kubernetes.io/docs/setup/learning-environment/minikube/
   • If you want to set up the base services(e.g. git, docker, docker-compose, openemr-cmd, minikube and kubectl) easily, please try openemr-env-installer
2. To start OpenEMR orchestration:

   bash kub-up

3. Can see pod progress with following command:

   kubectl get pod

   • It will look something like this:

     NAME                          READY   STATUS    RESTARTS   AGE
     mysql-565f988976-np9zs        1/1     Running   0          133m
     openemr-5f6db6c87c-8xgzq      1/1     Running   0          133m
     openemr-5f6db6c87c-bfktf      1/1     Running   0          133m
     openemr-5f6db6c87c-bwzdr      1/1     Running   0          133m
     openemr-5f6db6c87c-qn5ll      1/1     Running   0          133m
     openemr-5f6db6c87c-znq8h      1/1     Running   0          133m
     phpmyadmin-78968d6cfb-cdfmq   1/1     Running   0          133m
     redis-74cc9d667-5ltbq         1/1     Running   0          133m

4. Can see the service listing with following command:

   kubectl get svc

   • It will look something like this:

     NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                         AGE
     kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP                         151m
     mysql        ClusterIP   10.109.255.180   <none>        3306/TCP                        147m
     openemr      NodePort    10.104.48.53     <none>        8080:31314/TCP,8090:30613/TCP   147m
     phpmyadmin   NodePort    10.97.77.18      <none>        8081:30571/TCP                  147m
     redis        ClusterIP   10.98.24.148     <none>        6379/TCP                        147m

5. Can get the link to go to OpenEMR with following command (use the top link for http and bottom link for https):

   minikube service openemr --url

   • It will look something like this:

     http://192.168.99.100:31314
     http://192.168.99.100:30613

6. Can get the link to go to phpMyAdmin with following command:

   minikube service phpmyadmin --url

   • It will look something like this:

     http://192.168.99.100:30571

7. Some cool replicas stuff. The OpenEMR docker pods are run as a replica set (since it is set to 5 replicas in this OpenEMR deployment script). Gonna cover how to view the replica set and how to change the number of replicas on the fly in this step.
   • First. lets list the replica set like this:

     kubectl get rs

     • It will look something like this (note OpenEMR has 5 desired and 5 current replicas going):

       NAME                    DESIRED   CURRENT   READY   AGE
       mysql-64449b8cf7        1         1         1       4m5s
       openemr-5f6db6c87c      5         5         5       4m5s
       phpmyadmin-78968d6cfb   1         1         1       4m5s
       redis-74cc9d667         1         1         1       4m5s

   • Second, lets decrease OpenEMR's replicas from 5 to 2 (ie. pretend in an environment where don't need to expend resources of offering 5 replicas, perhaps after hours)

     kubectl scale deployment.v1.apps/openemr --replicas=2

     • It will return the following:

       deployment.apps/openemr scaled

     • Now, there are only 2 replicas of OpenEMR instead of 5. Enter the kubectl get rs and kubectl get pod to see what happened.
   • Third, lets increase OpenEMR's replicas from 2 to 10 (ie. pretend in an environment where a huge number of OpenEMR users are using the system at the same time)

     kubectl scale deployment.v1.apps/openemr --replicas=10

     • It will return the following:

       deployment.apps/openemr scaled

     • Now, there are 10 replicas of OpenEMR instead of 2. Enter the kubectl get rs and kubectl get pod to see what happened.
   • This is just a quick overview of scaling. Note we just did manual scaling in the example above, but there are also options of automatic scaling for example depending on cpu use etc.
8. To stop and remove OpenEMR orchestration (this will delete everything):

   bash kub-down