kubernetes installation using ansible

by Anish

Posted on Sunday July 8, 2018

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In this example we will learn how to install kubernetes using ansible

This demo utilizes the kubernetes official ansible playbook

Clone the official Ansible kubernetes repository in the ansible controller node

git clone https://github.com/kubernetes/contrib.git

Kubernetes Cluster Configuration

1. masters
2. etc
3. minion

Hostname definitions

| masters               | etc                   | minion                        |
|-------------------    |-------------------    |-----------------------------  |
| kube-master-node1     | kube-master-node1     | kube-minion-1 & kube-minion-2     |

Kubernetes Addon provided by the playbook by default

| Name                     | Descriptions                  |
|----------------------    |-----------------------------  |
| DNS                      | kubedns                       |
| cluster monitoring       | Grafana, Heapster, InfluxDB   |
| cluster logging          | Kibana, ElasticSearch         |
| Kubernetes dashboard     | UI                            |
| Kubernetes dash          | dash UI                       |

Lab Setup

[ansible@kube-master ~]# cat /etc/hosts
192.168.1.126 kube-master kube-master-node1
192.168.1.127 node1 kube-minion-1
192.168.1.128 node2 kube-minion-2

kubernetes installation started

Step-1 Install the required dependency yum -y install python-netaddr

Step-2 Install Ansible & setup required Ansible Keys in* all targeted nodes * make sure it has sudo access to the targeted node

ansible ALL=(ALL) NOPASSWD: ALL

[ansible@kube-master ~]ssh-keygen
[ansible@kube-master ~]ssh-copy-id kube-master-node1
[ansible@kube-master ~]ssh-copy-id kube-minion-1
[ansible@kube-master ~]ssh-copy-id kube-minion-1

Step-3 Go to ansible directory

[ansible@kube-master ~]# cd contrib/ansible

Step-4 Create the Inventory file and add masters,nodes & etcd hostgroup definitions

[ansible@kube-master ansible]# cat inventory/inventory
[masters]
kube-master-node1
[nodes]
kube-minion-1
kube-minion-2
[etcd:children]
masters

Configure Cluster options

Step-5 Check all the configured options inventory/group_vars/all.yml and adjust the records of your running enviroment, if you are unclear leave the default ones

cluster_name: cluster.mydns
master_cluster_hostname: kube-master
ansible_ssh_user: ansible
networking: flannel
ansible_ssh_user: DO CONFIGURE YOUR SSH Identity Logins 
etcd_url_scheme: "https"
etcd_client_cert_auth: true

Deploy the Cluster

Step-6 To deploy the cluster run the script, this will install all the addons by default

[ansible@kube-master contrib]cd scripts/ && ./deploy-cluster.sh

Wait for ansible-playbook Installation to complete

PLAY RECAP ******************************************************************************************************************************
kube-master-node1          : ok=215  changed=30   unreachable=0    failed=0   
kube-minion-1              : ok=115  changed=40   unreachable=0    failed=0   
kube-minion-2              : ok=111  changed=40   unreachable=0    failed=0   

Discovering builtin services

[ansible@kube-master ~]# kubectl cluster-info
Kubernetes master is running at http://localhost:8080
Elasticsearch is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/elasticsearch-logging
Heapster is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/heapster
Kibana is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/kibana-logging
KubeDNS is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/kube-dns
Grafana is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/monitoring-grafana
InfluxDB is running at http://localhost:8080/api/v1/proxy/namespaces/kube-system/services/monitoring-influxdb

Ansible Playbook Target Run

View the available scripts

[ansible@kube-master scripts]# ls -ltr 
total 60
-rw-r--r--. 1 root root   54 Jul  8 03:14 ansible.cfg
-rwxr-xr-x. 1 root root  817 Jul  8 03:14 update-node.sh
-rwxr-xr-x. 1 root root  819 Jul  8 03:14 update-master.sh
-rwxr-xr-x. 1 root root  817 Jul  8 03:14 update-etcd.sh
-rwxr-xr-x. 1 root root  823 Jul  8 03:14 restart-node.sh
-rwxr-xr-x. 1 root root  886 Jul  8 03:14 restart-master.sh
-rwxr-xr-x. 1 root root  800 Jul  8 03:14 restart-etcd.sh
-rwxr-xr-x. 1 root root  733 Jul  8 03:14 deploy-node.sh
-rwxr-xr-x. 1 root root  735 Jul  8 03:14 deploy-master.sh
-rwxr-xr-x. 1 root root 1441 Jul  8 03:14 deploy-local-cluster.sh
-rwxr-xr-x. 1 root root  733 Jul  8 03:14 deploy-etcd.sh
-rwxr-xr-x. 1 root root  735 Jul  8 03:14 deploy-docker.sh
-rwxr-xr-x. 1 root root  735 Jul  8 03:14 deploy-addons.sh
-rwxr-xr-x. 1 root root  736 Jul  8 03:31 deploy-cluster.sh
-rwxr-xr-x. 1 root root 1036 Jul  8 03:39 init.sh

Targeted Runs can be used to deploy the specific service present in the inventory file
Etcd Deployment

[ansible@kube-master scripts]./deploy-cluster.sh --tags=etcd

or

[ansible@kube-master scripts]./deploy-etcd.sh

Masters Deployment

[ansible@kube-master scripts]./deploy-cluster.sh --tags=masters

or

[ansible@kube-master scripts]./deploy-master

Nodes Deployment

[ansible@kube-master scripts]./deploy-cluster.sh --tags=nodes

or

[ansible@kube-master scripts]./deploy-node.sh

Check if the cluster is in a Ready state:

[ansible@kube-master ~]# kubectl get nodes
NAME            STATUS    AGE
kube-minion-1   Ready     1h
kube-minion-2   Ready     1h
[root@kube-master ~]# 

Check if all the pods are running:

[ansible@kube-master ~]# kubectl get pods --all-namespaces
NAMESPACE     NAME                                   READY     STATUS    RESTARTS   AGE
kube-system   elasticsearch-logging-v1-gzfnj         1/1       Running   0          1h
kube-system   elasticsearch-logging-v1-w9gjd         1/1       Running   0          1h
kube-system   fluentd-es-v1.20-4n77d                 1/1       Running   0          1h
kube-system   fluentd-es-v1.20-bvcln                 1/1       Running   0          1h
kube-system   heapster-v1.2.0-3740427991-m4nrr       4/4       Running   0          1h
kube-system   kibana-logging-3645747194-0kf5s        1/1       Running   0          1h
kube-system   kube-dns-v20-f27tg                     3/3       Running   0          1h
kube-system   monitoring-influxdb-grafana-v3-bv79x   2/2       Running   0          1h

Check the service IP address and ports the sample apps are running:

[ansible@kube-master ~]# kubectl get svc
NAME         CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   10.254.0.1   <none>        443/TCP   1h

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