docs/installation-k8s1node.rst

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Script for Setting Up 1-node Kubernetes Cluster
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The it/dep repo can be used for generating a simple script that can help setting up a
one-node Kubernetes cluster for dev and testing purposes.  Related files are under the
**tools/k8s/bin** directory. Clone the repository on the target VM:

::

  % git clone https://gerrit.o-ran-sc.org/r/it/dep


Configurations
^^^^^^^^^^^^^^

The generation of the script reads in the parameters from the following files:

- etc/env.rc: Normally no change needed for this file.  If where the Kubernetes cluster runs
  has special requirements, such as running private Docker registry with self-signed certificates,
  or hostnames that can be only resolved via private /etc/hosts entries, such parameters are
  entered into this file.
- etc/infra.rc: This file specifies the docker host, Kubernetes, and Kubernetes CNI versions.
  If a version is left empty, the installation will use the default version that the OS package
  management software would install.
- etc/openstack.rc: If the Kubernetes cluster is deployed on Open Stack VMs, this file specifies
  parameters for accessing the APIs of the Open Stack installation.  This is not supported in Amber
  release yet.


Generating Set-up Script
^^^^^^^^^^^^^^^^^^^^^^^^

After the configurations are updated, the following steps will create a script file that can be
used for setting up a one-node Kubernetes cluster.  You must run this command on a Linux machine
with the 'envsubst' command installed.

::

  % cd tools/k8s/bin
  % ./gen-cloud-init.sh

A file named **k8s-1node-cloud-init.sh** would now appear under the bin directory.


Setting up Kubernetes Cluster
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The new **k8s-1node-cloud-init.sh** file is now ready for setting up the Kubernetes cluster.

It can be run from a root shell of an existing Ubuntu 16.04 or 18.04 VM.  Running this script
will replace any existing installation of Docker host, Kubernetes, and Helm on the VM.  The
script will reboot the machine upon successful completion.  Run the script like this:

::

  % sudo -i
  # ./k8s-1node-cloud-init.sh

This script can also be used as the user-data (a.k.a. cloud-init script) supplied to Open Stack
when launching a new Ubuntu 16.04 or 18.04 VM.

Upon successful execution of the script and reboot of the machine, when queried in a root shell
with the kubectl command the VM should display information similar to below:

::

  # kubectl get pods --all-namespaces
  NAMESPACE     NAME                                   READY   STATUS       RESTARTS  AGE
  kube-system   coredns-5644d7b6d9-4gjp5               1/1     Running      0         103m
  kube-system   coredns-5644d7b6d9-pvsj8               1/1     Running      0         103m
  kube-system   etcd-ljitest                           1/1     Running      0         102m
  kube-system   kube-apiserver-ljitest                 1/1     Running      0         103m
  kube-system   kube-controller-manager-ljitest        1/1     Running      0         102m
  kube-system   kube-flannel-ds-amd64-nvjmq            1/1     Running      0         103m
  kube-system   kube-proxy-867v5                       1/1     Running      0         103m
  kube-system   kube-scheduler-ljitest                 1/1     Running      0         102m
  kube-system   tiller-deploy-68bf6dff8f-6pwvc         1/1     Running      0         102m