Kubernetes the hard way. Certficates

certficates.md

Creating Certificate Authority

Create common directory

cd ~/
mkdir kthw
cd kthw/

Update cfssl version

Check installation : https://gist.github.com/afym/1137acfd75e6c225ca04e99c91bbd6a1

sudo curl -s -L -o /bin/cfssl https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
sudo curl -s -L -o /bin/cfssljson https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
sudo curl -s -L -o /bin/cfssl-certinfo https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
sudo chmod +x /bin/cfssl*

Generate the certificate authority (ca : certificate authority and cacsr : certificate authority - certificate signing request)

{

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "8760h"
    },
    "profiles": {
      "kubernetes": {
        "usages": ["signing", "key encipherment", "server auth", "client auth"],
        "expiry": "8760h"
      }
    }
  }
}
EOF

cat > ca-csr.json << EOF
{
  "CN": "Kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "Kubernetes",
      "OU": "CA",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert -initca ca-csr.json | cfssljson -bare ca

}

Expected output

ca-config.json  ca-csr.json  ca-key.pem  ca.csr  ca.pem

Generating Client certificates

Change directory to common directory

cd kthw/

Create admin certificates

{

cat > admin-csr.json << EOF
{
  "CN": "admin",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:masters",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes \
  admin-csr.json | cfssljson -bare admin

}

Define your woker's Host and Ip

WORKER0_HOST=<Public hostname of your first worker node cloud server>
WORKER0_IP=<Private IP of your first worker node cloud server>
WORKER1_HOST=<Public hostname of your second worker node cloud server>
WORKER1_IP=<Private IP of your second worker node cloud server>

Create your worker certificates

{
cat > ${WORKER0_HOST}-csr.json << EOF
{
  "CN": "system:node:${WORKER0_HOST}",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:nodes",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -hostname=${WORKER0_IP},${WORKER0_HOST} \
  -profile=kubernetes \
  ${WORKER0_HOST}-csr.json | cfssljson -bare ${WORKER0_HOST}

cat > ${WORKER1_HOST}-csr.json << EOF
{
  "CN": "system:node:${WORKER1_HOST}",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:nodes",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -hostname=${WORKER1_IP},${WORKER1_HOST} \
  -profile=kubernetes \
  ${WORKER1_HOST}-csr.json | cfssljson -bare ${WORKER1_HOST}

}

Create controller manager certificate

{

cat > kube-controller-manager-csr.json << EOF
{
  "CN": "system:kube-controller-manager",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:kube-controller-manager",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes \
  kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager

}

Create proxy certificate

{

cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:node-proxier",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes \
  kube-proxy-csr.json | cfssljson -bare kube-proxy

}

Create scheduler certificate

{

cat > kube-scheduler-csr.json << EOF
{
  "CN": "system:kube-scheduler",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "system:kube-scheduler",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes \
  kube-scheduler-csr.json | cfssljson -bare kube-scheduler

}

Generating the Kubernetes API Server Certificate

cd ~/kthw

Internal IP in K8S cluster

CERT_HOSTNAME=10.32.0.1,<controller node 1 Private IP>,<controller node 1 hostname>,<controller node 2 Private IP>,<controller node 2 hostname>,<API load balancer Private IP>,<API load balancer hostname>,127.0.0.1,localhost,kubernetes.default

{

cat > kubernetes-csr.json << EOF
{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "Kubernetes",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -hostname=${CERT_HOSTNAME} \
  -profile=kubernetes \
  kubernetes-csr.json | cfssljson -bare kubernetes

}

Generating the Service Account Key Pair

cd ~/kthw

{

cat > service-account-csr.json << EOF
{
  "CN": "service-accounts",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "US",
      "L": "Portland",
      "O": "Kubernetes",
      "OU": "Kubernetes The Hard Way",
      "ST": "Oregon"
    }
  ]
}
EOF

cfssl gencert \
  -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes \
  service-account-csr.json | cfssljson -bare service-account

}

Move certificates

Move certificates to worker nodes (workers)

scp ca.pem <worker 1 hostname>-key.pem <worker 1 hostname>.pem user@<worker 1 public IP>:~/
scp ca.pem <worker 2 hostname>-key.pem <worker 2 hostname>.pem user@<worker 2 public IP>:~/

Move certificates to controller nodes (masters)

scp ca.pem ca-key.pem kubernetes-key.pem kubernetes.pem service-account-key.pem service-account.pem user@<controller 1 public IP>:~/
scp ca.pem ca-key.pem kubernetes-key.pem kubernetes.pem service-account-key.pem service-account.pem user@<controller 2 public IP>:~/