Chapter 7. Use cases 169
# oc get dc
NAME               REVISION   DESIRED   CURRENT   TRIGGERED BY
mongodb-36-rhel7   2          1         1         config,image(mongodb-36-rhel7:latest)
nodejs-ex          2          3         3         config,image(nodejs-ex:latest)
7.2  Hybrid architecture and multicloud applications: A true 
hybrid multicloud feel for the user
For containers, different architectures do not mean different types of deployments, even in a 
multicloud environment with different infrastructures. This section gives an example of how 
two different environments operate on different infrastructures, architectures, and OpenShift 
versions. Ephemeral containers that do not use persistent volumes are easy to migrate 
across different Kubernetes environments. 
This section also demonstrates migrating data that is on persistent volumes that are used by 
persistent application containers across environments to show the complete stack of a truly 
multicloud hybrid architecture.
7.2.1  Multicloud approach by using stateful MongoDB database
MongoDB is a NoSQL database that is being used widely as a backend for many 
applications. This scenario was selected because it shows the flexibility of working with 
containers on IBM Power Systems servers while using multicloud functions, even on stateful 
applications. 
The intent is to show with simple Yet Another Markup Language (yaml) files that the same 
user experience can be achieved, even by the administrator of the clusters. The yaml files can 
even be converted in templates later if needed for self service deployment. The user 
transparent experience is shown that uses MongoDB Compass client. The on-premise test 
environment is in Guadalajara (Mexico), the AWS zone is in Ohio (USA), and the client is in 
New York (US).
7.2.2  OpenShift Container Platform 3.11 ppc64le on-premises
For demonstration purposes, the on-premises scenario uses a small Power Systems 
OpenShift cluster with a single node, as shown in Example 7-10.
Example 7-10   OpenShift 3.11 cluster on a Power Systems node
[root@dcocp01 ~]# oc get nodes -o json |grep -A10 "nodeInfo"
                "nodeInfo": {
                    "architecture": "ppc64le",
                    "bootID": "5d13a724-e909-4481-a617-ebd9acf4e020",
                    "containerRuntimeVersion": "docker://1.13.1",
                    "kernelVersion": "4.14.0-115.13.1.el7a.ppc64le",
                    "kubeProxyVersion": "v1.11.0+d4cacc0",
                    "kubeletVersion": "v1.11.0+d4cacc0",
                    "machineID": "28803bf7ab784a0796e22f40f33a2827",
                    "operatingSystem": "linux",
                    "osImage": "OpenShift Enterprise",
                    "systemUUID": "IBM,037892CBA\u0000"
[root@dcocp01 ~]#