pouch_with_kubernetes_deploying.md

Deploy Kubernetes With PouchContainer

Updated: 2018.6.1

• PouchContainer deploying
  • Overview
  • Restriction
  • Install and Configure
    • Install PouchContainer
    • Setup Repo
    • Install Kubernetes Components
    • Install CNI
    • Setting up the master node
    • Setting up the minion nodes
  • Run and Verify
  • Troubleshooting

Overview

This document shows how to easily install a Kubernetes cluster with PouchContainer as the container runtime.For Chinese customer, it's might be faster and easier to download Kubernetes components and various kinds of container images from Aliyun Kubernetes + PouchContainer + Aliyun.

Restriction

Kubernetes: Version 1.5+ is recommanded.

NOTE: PouchContainer version prior to 0.5.x (including version 0.5.0) did not support configuring CNI network plugin with flannel. If you want to do that, use the latest code from the branch of master, refer to Developer Quick-Start

Install and Configure

An all-in-one kubernetes cluster with PouchContainer runtime could be deployed by running:

hack/kubernetes/allinone.sh

Please refer to allinone .

Install PouchContainer

You can easily setup a basic PouchContainer environment, see INSTALLATION.md.

Configure PouchContainer

On Ubuntu 16.04+:

NOTE: If you'd like to use Kubernetes 1.10+, CRI_VERSION should be "v1alpha2"

CRI_VERSION="v1alpha1"
sed -i 's/ExecStart=\/usr\/bin\/pouchd/ExecStart=\/usr\/bin\/pouchd --enable-cri=true --cri-version=${CRI_VERSION}/g' /usr/lib/systemd/system/pouch.service
systemctl daemon-reload
systemctl restart pouch

On CentOS 7:

NOTE: If you'd like to use Kubernetes 1.10+, CRI_VERSION should be "v1alpha2"

CRI_VERSION="v1alpha1"
sed -i 's/ExecStart=\/usr\/local\/bin\/pouchd/ExecStart=\/usr\/local\/bin\/pouchd --enable-cri=true --cri-version=${CRI_VERSION}/g' /lib/systemd/system/pouch.service
systemctl daemon-reload
systemctl restart pouch

Setup Repo

On Ubuntu 16.04+:

apt-get update && apt-get install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update

On CentOS 7:

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://yum.kubernetes.io/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
       https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

Install Kubernetes Components

On Ubuntu 16.04+:

RELEASE="1.9.4-00"
apt-get -y install kubelet=${RELEASE} kubeadm=${RELEASE} kubectl=${RELEASE}

On CentOS 7:

RELEASE="1.9.4-0.x86_64"
yum install -y kubelet-${RELEASE} kubeadm-${RELEASE} kubectl-${RELEASE}

Configure kubelet with PouchContainer as its runtime:

sed -i '2 i\Environment="KUBELET_EXTRA_ARGS=--container-runtime=remote --container-runtime-endpoint=unix:///var/run/pouchcri.sock --image-service-endpoint=unix:///var/run/pouchcri.sock"' /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
systemctl daemon-reload

For more details, please check install kubelet.

Install CNI

On Ubuntu 16.04+:

apt-get install -y kubernetes-cni

On CentOS 7:

setenforce 0
yum install -y kubernetes-cni

Setting up the master node

For more detailed Kubernetes cluster installation, please check Using kubeadm to Create a Cluster

kubeadm init --pod-network-cidr 10.244.0.0/16 --ignore-preflight-errors=all

Set the KUBECONFIG environment variable

export KUBECONFIG=/etc/kubernetes/admin.conf

Configure CNI network plugin with flannel

kubectl create -f https://github.com/coreos/flannel/raw/master/Documentation/kube-flannel.yml

NOTE: For other plugins, please check Installing a pod network.

Optional: enable schedule pods on the master node

kubectl taint nodes --all node-role.kubernetes.io/master:NoSchedule-

Setting up the minion nodes

After initializing the master node, you may get the following prompt:

You can now join any number of machines by running the following on each node
as root:

  kubeadm join --token $token ${master_ip:port} --discovery-token-ca-cert-hash $ca-cert

NOTE: Because kubeadm still assumes docker as the only container runtime ,Use the flag --ignore-preflight-errors=all to skip the check.

Copy & Run it in all your minion nodes.

Run and Verify

Create a deployment named Pouch:

# cat pouch.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: pouch
  labels:
    pouch: pouch
spec:
  selector:
    matchLabels:
      pouch: pouch
  template:
    metadata:
      labels:
        pouch: pouch
    spec:
      containers:
      - name: pouch
        image: docker.io/library/nginx:latest
        ports:
        - containerPort: 80

# kubectl create -f pouch.yaml
deployment "pouch" created

Confirm the pod of deployment is really running:

# kubectl get pods -o wide
NAME                     READY     STATUS    RESTARTS   AGE       IP           NODE
pouch-7dcd875d69-gq5r9   1/1       Running   0          44m       10.244.1.4   master
# curl 10.244.1.4
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

Troubleshooting

• Because kubeadm still assumes docker as the only container runtime which can be used with kubernetes. When you use kubeadm to initialize the master node or join the minion node to the cluster, you may encounter the following error message:[ERROR SystemVerification]: failed to get docker info: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?. Use the flag --ignore-preflight-errors=all to skip the check, like kubeadm init --ignore-preflight-errors=all.

• By default PouchContainer will support CRI v1alpha2,which means that using a version of Kubernetes prior to 1.10 will not work. As the NOTE mentioned above, we could start pouchd with the configuration like pouchd --cri-version v1alpha1 to specify the version of CRI to support the version of Kubernetes below 1.10.

• By default PouchContainer will not enable the CRI. If you'd like to deploy Kubernetes with PouchContainer, you should start pouchd with the configuration like pouchd --enable-cri.

• By default PouchContainer will use registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0 as the image of infra container. If you'd like use image other than that, you could start pouchd with the configuration like pouchd --enable-cri --sandbox-image XXX.

• Any other troubles? Make an issue to connect with us!