Setting up RKE Cluster

Centos 7.5
Docker 17.03
Kubernetes 1.11

Preparation

===========

1. Download latest RKE binary in https://github.com/rancher/rke/releases/.

2. Create separate partition for docker data.

pvcreate /dev/sdb
vgcreate docker_vg /dev/sdb
lvcreate -n docker_lv -l 100%FREE docker_vg
mkfs.xfs /dev/mapper/docker_vg-docker_lv
echo "/dev/mapper/docker_vg-docker_lv  /var/lib/docker  xfs  defaults  0 0" >> /etc/fstab
mkdir -p /var/lib/docker
mount -a

3. Install docker-ce 17.03.

curl https://releases.rancher.com/install-docker/17.03.sh | sh
systemctl enable --now dockervm.

4. Disable swappiness.

echo "vm.swappiness = 0" >> /etc/sysctl.conf
sysctl -p

5. Disable Network Manager.

systemctl disable --now NetworkManager

6. Allow the following ports in the firewall.

cat << EOF > ports.txt
6443/tcp
2376/tcp
2379/tcp
2380/tcp
8472/tcp
10250/tcp
80/tcp
443/tcp
30000-32767/tcp
EOF
for port in $(cat ports.txt); do firewall-cmd --add-port=$port --permanent; done

7. Load needed kernel modules.

cat << EOF > modules.txt
br_netfilter
ip6_udp_tunnel
ip_set
ip_set_hash_ip
ip_set_hash_net
iptable_filter
iptable_nat
iptable_mangle
iptable_raw
nf_conntrack_netlink
nf_conntrack
nf_conntrack_ipv4
nf_defrag_ipv4
nf_nat
nf_nat_ipv4
nf_nat_masquerade_ipv4
nfnetlink
udp_tunnel
veth
vxlan
x_tables
xt_addrtype
xt_conntrack
xt_comment
xt_mark
xt_multiport
xt_nat
xt_recent
xt_set
xt_statistic
xt_tcpudp
EOF
for module in $(cat modules.txt); do modprobe $module; done

8. Add the following line in /usr/lib/systemd/system/docker.service.

[...]
KillMode=process
MountFlags=shared
[...]
systemctl daemon-reload
ssytemctl restart docker

9. Allow SSH tunelling and forwarding. Update sshd_config.

[...]
AllowTcpForwarding yes
PermitTunnel yes
[...]
systemctl restart sshd

10. Get kubectl.

curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/darwin/amd64/kubectl
mv kubectl /usr/local/bin/

Bootstrap the cluster

=====================

1. Generate RKE config. This will allow you to answer a series of
questions regarding the cluster. It will generate "cluster.yml" to
be used on the next step.

rke config

2. Bootstrap cluster.

rke up