144 lines
4.5 KiB
ReStructuredText
144 lines
4.5 KiB
ReStructuredText
=====================
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Gate-Based Kubernetes
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=====================
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Overview
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========
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You can use any Kubernetes deployment tool to bring up a working Kubernetes
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cluster for use with OpenStack-Helm. This guide describes how to simply stand
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up a multinode Kubernetes cluster via the OpenStack-Helm gate scripts,
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which use KubeADM and Ansible. Although this cluster won't be
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production-grade, it will serve as a quick starting point in a lab or
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proof-of-concept environment.
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OpenStack-Helm-Infra KubeADM deployment
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=======================================
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On the worker nodes:
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.. code-block:: shell
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#!/bin/bash
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set -xe
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sudo apt-get update
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sudo apt-get install --no-install-recommends -y git
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SSH-Key preparation
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-------------------
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Create an ssh-key on the master node, and add the public key to each node that
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you intend to join the cluster.
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.. note::
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1. To generate the key you can use ``ssh-keygen -t rsa``
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2. To copy the ssh key to each node, this can be accomplished with
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the ``ssh-copy-id`` command, for example: *ssh-copy-id
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ubuntu@192.168.122.178*
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3. Copy the key: ``sudo cp ~/.ssh/id_rsa /etc/openstack-helm/deploy-key.pem``
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4. Set correct ownership: ``sudo chown ubuntu
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/etc/openstack-helm/deploy-key.pem``
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Test this by ssh'ing to a node and then executing a command with
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'sudo'. Neither operation should require a password.
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Clone the OpenStack-Helm Repos
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------------------------------
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Once the host has been configured the repos containing the OpenStack-Helm charts
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should be cloned onto each node in the cluster:
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.. code-block:: shell
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#!/bin/bash
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set -xe
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sudo chown -R ubuntu: /opt
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git clone https://git.openstack.org/openstack/openstack-helm-infra.git /opt/openstack-helm-infra
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git clone https://git.openstack.org/openstack/openstack-helm.git /opt/openstack-helm
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Create an inventory file
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------------------------
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On the master node create an inventory file for the cluster:
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.. note::
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node_one, node_two and node_three below are all worker nodes,
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children of the master node that the commands below are executed on.
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.. code-block:: shell
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#!/bin/bash
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set -xe
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cat > /opt/openstack-helm-infra/tools/gate/devel/multinode-inventory.yaml <<EOF
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all:
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children:
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primary:
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hosts:
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node_one:
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ansible_port: 22
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ansible_host: $node_one_ip
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ansible_user: ubuntu
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ansible_ssh_private_key_file: /etc/openstack-helm/deploy-key.pem
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ansible_ssh_extra_args: -o StrictHostKeyChecking=no
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nodes:
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hosts:
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node_two:
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ansible_port: 22
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ansible_host: $node_two_ip
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ansible_user: ubuntu
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ansible_ssh_private_key_file: /etc/openstack-helm/deploy-key.pem
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ansible_ssh_extra_args: -o StrictHostKeyChecking=no
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node_three:
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ansible_port: 22
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ansible_host: $node_three_ip
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ansible_user: ubuntu
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ansible_ssh_private_key_file: /etc/openstack-helm/deploy-key.pem
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ansible_ssh_extra_args: -o StrictHostKeyChecking=no
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EOF
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Create an environment file
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--------------------------
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On the master node create an environment file for the cluster:
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.. code-block:: shell
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#!/bin/bash
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set -xe
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function net_default_iface {
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sudo ip -4 route list 0/0 | awk '{ print $5; exit }'
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}
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cat > /opt/openstack-helm-infra/tools/gate/devel/multinode-vars.yaml <<EOF
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kubernetes_network_default_device: $(net_default_iface)
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EOF
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Additional configuration variables can be found `here
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<https://github.com/openstack/openstack-helm-infra/blob/master/roles/deploy-kubeadm-aio-common/defaults/main.yml>`_.
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In particular, ``kubernetes_cluster_pod_subnet`` can be used to override the
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pod subnet set up by Calico (the default container SDN), if you have a
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preexisting network that conflicts with the default pod subnet of 192.168.0.0/16.
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.. note::
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This installation, by default will use Google DNS servers, 8.8.8.8 or 8.8.4.4
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and updates resolv.conf. These DNS nameserver entries can be changed by
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updating file ``/opt/openstack-helm-infra/tools/images/kubeadm-aio/assets/opt/playbooks/vars.yaml``
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under section ``external_dns_nameservers``. This change must be done on each
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node in your cluster.
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Run the playbooks
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-----------------
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On the master node run the playbooks:
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.. code-block:: shell
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#!/bin/bash
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set -xe
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cd /opt/openstack-helm-infra
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make dev-deploy setup-host multinode
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make dev-deploy k8s multinode
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