kubernetes-the-hard-way/docs/05-kubernetes-worker.md

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# Bootstrapping Kubernetes Workers
In this lab you will bootstrap 3 Kubernetes worker nodes. The following virtual machines will be used:
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```
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gcloud compute instances list
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```
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````
NAME ZONE MACHINE_TYPE PREEMPTIBLE INTERNAL_IP EXTERNAL_IP STATUS
worker0 us-central1-f n1-standard-1 10.240.0.30 XXX.XXX.XXX.XXX RUNNING
worker1 us-central1-f n1-standard-1 10.240.0.31 XXX.XXX.XXX.XXX RUNNING
worker2 us-central1-f n1-standard-1 10.240.0.32 XXX.XXX.XXX.XXX RUNNING
````
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## Why
Kubernetes worker nodes are responsible for running your containers. All Kubernetes clusters need one or more worker nodes. We are running the worker nodes on dedicated machines for the following reasons:
* Ease of deployment and configuration
* Avoid mixing arbitrary workloads with critical cluster components. We are building machine with just enough resources so we don't have to worry about wasting resources.
Some people would like to run workers and cluster services anywhere in the cluster. This is totally possible, and you'll have to decide what's best for your environment.
## Provision the Kubernetes Worker Nodes
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Run the following commands on `worker0`, `worker1`, `worker2`:
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> SSH into each machine using the `gcloud compute ssh` command
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#### Move the TLS certificates in place
```
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sudo mkdir -p /var/lib/kubernetes
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```
```
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sudo mv ca.pem kubernetes-key.pem kubernetes.pem /var/lib/kubernetes/
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```
#### Docker
Kubernetes should be compatible with the Docker 1.9.x - 1.11.x:
```
wget https://get.docker.com/builds/Linux/x86_64/docker-1.11.2.tgz
```
```
tar -xvf docker-1.11.2.tgz
```
```
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sudo cp docker/docker* /usr/bin/
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```
Create the Docker systemd unit file:
```
sudo sh -c 'echo "[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.io
[Service]
ExecStart=/usr/bin/docker daemon \
--iptables=false \
--ip-masq=false \
--host=unix:///var/run/docker.sock \
--log-level=error \
--storage-driver=overlay
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target" > /etc/systemd/system/docker.service'
```
```
sudo systemctl daemon-reload
sudo systemctl enable docker
sudo systemctl start docker
```
```
sudo docker version
```
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#### kubelet
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The Kubernetes kubelet no longer relies on docker networking for pods! The Kubelet can now use [CNI - the Container Network Interface](https://github.com/containernetworking/cni) to manage machine level networking requirements.
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Download and install CNI plugins
```
sudo mkdir -p /opt/cni
```
```
wget https://storage.googleapis.com/kubernetes-release/network-plugins/cni-c864f0e1ea73719b8f4582402b0847064f9883b0.tar.gz
```
```
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sudo tar -xvf cni-c864f0e1ea73719b8f4582402b0847064f9883b0.tar.gz -C /opt/cni
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```
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Download and install the Kubernetes worker binaries:
```
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wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kubectl
wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kube-proxy
wget https://storage.googleapis.com/kubernetes-release/release/v1.3.0/bin/linux/amd64/kubelet
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```
```
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chmod +x kubectl kube-proxy kubelet
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```
```
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sudo mv kubectl kube-proxy kubelet /usr/bin/
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```
```
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sudo mkdir -p /var/lib/kubelet/
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```
```
sudo sh -c 'echo "apiVersion: v1
kind: Config
clusters:
- cluster:
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certificate-authority: /var/lib/kubernetes/ca.pem
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server: https://10.240.0.20:6443
name: kubernetes
contexts:
- context:
cluster: kubernetes
user: kubelet
name: kubelet
current-context: kubelet
users:
- name: kubelet
user:
token: chAng3m3" > /var/lib/kubelet/kubeconfig'
```
Create the kubelet systemd unit file:
```
sudo sh -c 'echo "[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service
[Service]
ExecStart=/usr/bin/kubelet \
--allow-privileged=true \
--api-servers=https://10.240.0.20:6443,https://10.240.0.21:6443,https://10.240.0.22:6443 \
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--cloud-provider= \
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--cluster-dns=10.32.0.10 \
--cluster-domain=cluster.local \
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--configure-cbr0=true \
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--container-runtime=docker \
--docker=unix:///var/run/docker.sock \
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--network-plugin=kubenet \
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--kubeconfig=/var/lib/kubelet/kubeconfig \
--reconcile-cidr=true \
--serialize-image-pulls=false \
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--tls-cert-file=/var/lib/kubernetes/kubernetes.pem \
--tls-private-key-file=/var/lib/kubernetes/kubernetes-key.pem \
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--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target" > /etc/systemd/system/kubelet.service'
```
```
sudo systemctl daemon-reload
sudo systemctl enable kubelet
sudo systemctl start kubelet
```
```
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sudo systemctl status kubelet --no-pager
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```
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#### kube-proxy
```
sudo sh -c 'echo "[Unit]
Description=Kubernetes Kube Proxy
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
ExecStart=/usr/bin/kube-proxy \
--master=https://10.240.0.20:6443 \
--kubeconfig=/var/lib/kubelet/kubeconfig \
--proxy-mode=iptables \
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target" > /etc/systemd/system/kube-proxy.service'
```
```
sudo systemctl daemon-reload
sudo systemctl enable kube-proxy
sudo systemctl start kube-proxy
```
```
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sudo systemctl status kube-proxy --no-pager
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```
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> Remember to run these steps on `worker0`, `worker1`, and `worker2`