Classroom Example with Kubespray and Digital Rebar

That’s helpful to built-test-destroy coordinated Kubernetes installs on CentOS, Red Hat and Ubuntu as part of an automation pipeline. We can also set up a full classroom environment from a single command using [Digital Rebar’s](https://github.com/digitalrebar/digitalrebar) providers, tenants and cluster definition JSON. **Let’s explore the classroom example:** First, we define a [student cluster in JSON](https://github.com/digitalrebar/digitalrebar/blob/master/deploy/workloads/cluster/deploy-001.json) like the snippet below | {  "attribs": {    "k8s-version": "v1.6.0",    "k8s-kube\_network\_plugin": "calico",    "k8s-docker\_version": "1.12"  },  "name": "cluster01",  "tenant": "cluster01",  "public\_keys": {    "cluster01": "ssh-rsa AAAAB..... user@example.com"  },  "provider": {    "name": "google-provider"  },  "nodes": [    {      "roles": ["etcd","k8s-addons", "k8s-master"],      "count": 1    },    {      "roles": ["k8s-worker"],      "count": 3    }  ] } | Then we run the [Digital Rebar workloads Multideploy.sh](https://github.com/digitalrebar/digitalrebar/blob/master/deploy/workloads/multideploy.sh) reference script which inspects the deployment files to pull out key information.  Basically, it automates the following steps: | rebar provider create {“name”:“google-provider”, [secret stuff]} rebar tenants create {“name”:“cluster01”} rebar deployments create [contents from cluster01 file] | The deployments create command will automatically request nodes from the provider. Since we’re using tenants and SSH key additions, each student only gets access to their own cluster. When we’re done, adding the --destroy flag will reverse the process for the nodes and deployments but leave the providers and tenants. **We are invested in operational scripts like this example using Kubespray and Digital Rebar because if we cannot manage variation in a consistent way then we’re doomed to operational fragmentation.  ** I am excited to see and be part of the community progress towards enterprise-ready Kubernetes operations on both cloud and on-premises. That means I am seeing reasonable patterns emerge with sharable/reusable automation. I strongly recommend watching (or better, collaborating in) these efforts if you are deploying Kubernetes even at experimental scale. Being part of the community requires more upfront effort but returns dividends as you get the benefits of shared experience and improvement. **When deploying at scale, how do you set up a system to be both repeatable and multi-platform without compromising scale or security?** With Kubespray and Digital Rebar as a repeatable base, extensions get much faster and easier. Even better, using upstream directly allows improvements to be quickly cycled back into upstream. That means we’re closer to building a community focused on the operational side of Kubernetes with an [SRE mindset](https://rackn.com/sre). If this is interesting, please engage with us in the [Cluster Ops SIG](https://github.com/kubernetes/community/tree/master/sig-cluster-ops), [Kubespray](https://github.com/kubernetes-incubator/kubespray) or [Digital Rebar](http://rebar.digital/) communities.  - Get involved with the Kubernetes project on [GitHub](https://github.com/kubernetes/kubernetes) - Post questions (or answer questions) on [Stack Overflow](http://stackoverflow.com/questions/tagged/kubernetes) - Connect with the community on [Slack](http://slack.k8s.io/) - Follow us on Twitter [@Kubernetesio](https://twitter.com/kubernetesio) for latest updates

The provided text details a classroom example of deploying Kubernetes using Kubespray and Digital Rebar. It explains how to define a student cluster in JSON and use the Digital Rebar workloads Multideploy.sh script to automate the creation of providers, tenants, and deployments. The script ensures that each student has access only to their own cluster. The author emphasizes the importance of repeatable and multi-platform systems for managing variation and avoiding operational fragmentation, advocating for community involvement to improve Kubernetes operations.