Singular

Singular is designed to deploy ContainerOps platform, mainly focus on Kubernetes, Prometheus, and other Cloud Native technology stack. The goal is to build the stack across clouds, OpenStack, VMs and even bare metals.

Singular doesn't use any other deploy tools like kubeadm, but deploys everything in a hard way instead. The hard way means, user prepare all the binaries, nodes and SSH keys to nodes, then singular will copy the binaries to the nodes, generate configs, CA, systemd scripts, and start the service. The process is just like you deploy a kubernetes cluster manually.

Singular provides templates of different service version combinations, currently the services include etcd, flannel, docker-ce and Kubernetes. More CNCF projects will be supported in the future.

The latest supported kubernetes version is 1.13.0

Where to get the binaries?

Since singular deploy the Kubernetes cluster in the hard way, you can get all the binaries that singular needs here below:

etcd: https://github.com/etcd-io/etcd/releases

flannel: https://github.com/coreos/flannel/releases

docker: https://download.docker.com/

kubernetes: https://github.com/kubernetes/kubernetes/releases

For Chinese users, it's recommended to download the docker-ce binaries from mirror sites aliyun, or Tsinghua University

Deployment Template

Singular uses a YAML file as deployment template, it describes the architecture of the cluster, including the nodes' info, the services' metadata like binary path, version etc. The sample templates can be found in ./external/public/data/cncf.build. The structure is like this:

uri: containerops/singular/etcd-3.2.8-flanneld-0.7.1-docker-17.04.0-ce-k8s-1.9.2
title: Deploy Kubernetes With etcd-3.2.8 flanneld-0.7.1 docker-17.04.0-ce k8s-1.9.2
tag: latest
nodes: # 3 nodes is provided at least, the first one will be deployed as kubernetes master node
  -
    ip: 192.168.43.70
    user: root
    distro: archlinux # distro could be 'ubuntu', 'centos' or 'archlinux'
  -
    ip: 192.168.43.71
    user: root
    distro: archlinux
  -
    ip: 192.168.43.72
    user: root
    distro: archlinux
tools:
  ssh: # The ssh key to target nodes
    private: /home/lance/.ssh/id_rsa
    public: /home/lance/.ssh/id_rsa.pub
infras:
  -
    name: etcd
    version: etcd-3.2.8
    master: 3
    minion: 0
    components:
      -
        binary: etcd
        url: /my/k8s-binaries/etcd/3.2.8/etcd  # The value can be file path or http url
        package: false
        systemd: etcd-3.2.8
        ca: etcd-3.2.8
      -
        binary: etcdctl
        url: /my/k8s-binaries/etcd/3.2.8/etcdctl
        package: false
  -
......

SSH Key

When deploying infrastructures, Singular needs to SSH into virtual machines or bare metals.

1. Provide SSH private key at least, Singular will create public key from it. To generate ssh key, follow the Github document - How to generate SSH Key.
2. If SSH key files are not specified in deployment template, Singular will create SSH pair key files in default folder($HOME/.containerops/ssh) and name them (id_rsa.pub and id_rsa).

Deploy Command

$ singular deploy template /tmp/deploy.yml  --verbose --timestamp

Then, copy the kubeconfig file into the default folder to make it easier play with kubectl:

# The path might vary with your template name
$ cp cp ~/.containerops/singular/containerops/singular/etcd-3.3.9-flanneld-0.10.0-docker-18.06.1-ce-k8s-1.12.0/0/kubectl/config ~/.kube

The next step

After deploying the Kubernetes cluster, the in-cluster DNS is not installed by default, a kubernetes cluster usually use CoreDNS(recommended) or KubeDNS as name server. The yaml files are already there for the newly deployed cluster, you can set them up by:

kubectl apply -f $GOPATH/src/github/Huawei/containerops/singular/external/public/data/dns/kubedns-latest.yaml

Or CoreDNS:

kubectl apply -f $GOPATH/src/github/Huawei/containerops/singular/external/public/data/dns/coredns-latest.yaml

The __PILLAR__DNS__SERVER__ and __PILLAR__DNS__DOMAIN__ are preconfigured according to the kubelet template file(that it, 10.254.0.2 and cluster.local.). Feel free to change them to meet your own requirements.