This repo contains the necessary files to provision kuberenets cluster I will try step by step approach for this.
Note: We need ansible to complete this cluster creation
I am using Neon User (Ubuntu 20-04) for this purpose. First install lxd runtime as below.
sudo snap install lxdsudo snap start lxdsudo snap enable lxd
Initialize the container runtime
sudo lxd init
Would you like to use LXD clustering? (yes/no) [default=no]: no
Do you want to configure a new storage pool? (yes/no) [default=yes]: yes
Name of the new storage pool [default=default]:
Name of the storage backend to use (btrfs, dir, lvm) [default=btrfs]: dir
Would you like to connect to a MAAS server? (yes/no) [default=no]: no
Would you like to create a new local network bridge? (yes/no) [default=yes]:
What should the new bridge be called? [default=lxdbr0]:
What IPv4 address should be used? (CIDR subnet notation, “auto” or “none”) [default=auto]:
What IPv6 address should be used? (CIDR subnet notation, “auto” or “none”) [default=auto]: none
Would you like LXD to be available over the network? (yes/no) [default=no]: no
Would you like stale cached images to be updated automatically? (yes/no) [default=yes] yes
Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]: no
lxc profile create k8s
lxc profile edit k8s
Copy the contents from lxd-profile into k8s profile.
Launch the containers, i will choose centos 7 for this task
lxc launch images:centos/7 kube-master --profile k8s
lxc launch images:centos/7 kube-w01 --profile k8s
lxc launch images:centos/7 kube-w02 --profile k8s
Once the containers are ready check them they are created
lxc list
+------------------+---------+------+------+-----------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------------------+---------+------+------+-----------+-----------+
| kube-master | STOPPED | | | CONTAINER | 0 |
+------------------+---------+------+------+-----------+-----------+
| kube-w01 | STOPPED | | | CONTAINER | 0 |
+------------------+---------+------+------+-----------+-----------+
| kube-w02 | STOPPED | | | CONTAINER | 0 |
+------------------+---------+------+------+-----------+-----------+
Launch the containers
lxc start kube-master kube-w01 kube-w02
Exec into kube-master container by
lxc exec kube-master bash
and install openssh server
yum install openssh-server -y
systemctl enable sshd && systemctl start sshd
set the root password to login through ssh
passwd
Do the above step from exec to installation & start off ssh on other containers as well.
To complete this guide and to successfully install docker & kubernetes we need ansible. Please install ansible in your host machine you can sue pythone package manager to install ansible.
pip3 install ansible
Once the ansible installed exchage your ssh keys with all the running containers for example my lxc list list shows one of container as below
+------------------+---------+----------------------+------+-----------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------------------+---------+----------------------+------+-----------+-----------+
| kube-master | RUNNING | 172.25.25.129 (eth0) | | CONTAINER | 0 |
+------------------+---------+----------------------+------+-----------+-----------+
ssh-copy-id root@172.25.25.129
Do this with all the other two nodes.
Once done go to the inventory file in the repo and update the IPs under the sections
[kube_master]
[kube_workers]
save the file & check if ansible can talk to those hosts by sending ping module command.
❯ ansible -m ping all
172.25.25.129 | SUCCESS => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false,
"ping": "pong"
}
172.25.25.96 | SUCCESS => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false,
"ping": "pong"
}
172.25.25.190 | SUCCESS => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false,
"ping": "pong"
}
Once you can reach to those containers, run the commands respectively in your host machine.
ansible-playbook docker.yaml
Since I have already ran the playbook the out put with your terminal might be differrent but similar.
❯ ansible-playbook docker.yaml
PLAY [Install docker on all hosts] ***************************************************************************************************************************
TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.96]
ok: [172.25.25.129]
TASK [Install yum utils] *************************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.96]
ok: [172.25.25.129]
TASK [Install device-mapper-persistent-data] *****************************************************************************************************************
ok: [172.25.25.129]
ok: [172.25.25.190]
ok: [172.25.25.96]
TASK [Install lvm2] ******************************************************************************************************************************************
ok: [172.25.25.129]
ok: [172.25.25.96]
ok: [172.25.25.190]
TASK [Add Docker repo] ***************************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Install Docker] ****************************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Start Docker service] **********************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
PLAY RECAP ***************************************************************************************************************************************************
172.25.25.129 : ok=7 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
172.25.25.190 : ok=7 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
172.25.25.96 : ok=7 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
❯ ansible-playbook kube8s.yaml
PLAY [Install kuberenetes packages on all hosts] *************************************************************************************************************
TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Copy kubernetes repo file to servers] ******************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Copy k8s.conf file to servers] *************************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Copy docker custom daeom file to servers] **************************************************************************************************************
changed: [172.25.25.96]
changed: [172.25.25.129]
changed: [172.25.25.190]
TASK [Create a directory if it does not exist] ***************************************************************************************************************
ok: [172.25.25.190]
ok: [172.25.25.129]
ok: [172.25.25.96]
TASK [Installing kubeadm, kubelet and kubectl] ***************************************************************************************************************
changed: [172.25.25.129]
changed: [172.25.25.190]
changed: [172.25.25.96]
TASK [Restart & enable kubelet service] **********************************************************************************************************************
changed: [172.25.25.190]
changed: [172.25.25.129]
changed: [172.25.25.96]
TASK [Restart & enable docker service] ***********************************************************************************************************************
changed: [172.25.25.190]
changed: [172.25.25.129]
changed: [172.25.25.96]
PLAY RECAP ***************************************************************************************************************************************************
172.25.25.129 : ok=8 changed=4 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
172.25.25.190 : ok=8 changed=4 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
172.25.25.96 : ok=8 changed=4 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
We have succefully installed the docker & the binaries to create kubernetes cluster by running the abvoe mentioned playbooks.
Let's exec into kube-master container & boot strap the cluster.
lxc exec kube-master bash
echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables
Make sure you run thie above command on all nodes
kubeadm init --pod-network-cidr=10.244.0.0/16
Your Kubernetes control-plane has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 172.25.25.129:6443 --token sntzcn.9rs6sr5fsr1koeju \
--discovery-token-ca-cert-hash sha256:c811d8e88bbad04b06d892be678e51dfb66639935f361bc379c9ddc11c3375af
Our cluster master is ready, we have to install cni plugin for node connectivity.
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
[root@kube-master ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged configured
clusterrole.rbac.authorization.k8s.io/flannel unchanged
clusterrolebinding.rbac.authorization.k8s.io/flannel unchanged
serviceaccount/flannel unchanged
configmap/kube-flannel-cfg unchanged
daemonset.apps/kube-flannel-ds unchanged
[root@kube-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-master Ready master 5m28s v1.19.7
[root@kube-master ~]#
Once the plugin is installed & flannel posd is running, now we can exec into other workers to join them to master.
[root@kube-master ~]# kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-f9fd979d6-9v5pb 1/1 Running 0 5m49s
kube-system coredns-f9fd979d6-m2zbv 1/1 Running 0 5m49s
kube-system etcd-kube-master 1/1 Running 0 5m58s
kube-system kube-apiserver-kube-master 1/1 Running 0 5m58s
kube-system kube-controller-manager-kube-master 1/1 Running 0 5m58s
kube-system kube-flannel-ds-db6zd 1/1 Running 0 66s
kube-system kube-proxy-4w96c 1/1 Running 0 5m48s
kube-system kube-scheduler-kube-master 1/1 Running 0 5m58s
[root@kube-master ~]#
kubeadm join 172.25.25.129:6443 --token sntzcn.9rs6sr5fsr1koeju \
--discovery-token-ca-cert-hash sha256:c811d8e88bbad04b06d892be678e51dfb66639935f361bc379c9ddc11c3375af
We will get back to master by lxc exec kube-master bash and check if our nodes already joined to master or no.
[root@kube-master ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube-master Ready master 10m v1.19.7
kube-w01 Ready <none> 2m6s v1.19.7
kube-w02 Ready <none> 33s v1.19.7
[root@kube-master ~]#