- Lab
- Cloud
- Security
Creating a Certificate Authority and TLS Certificates for Kubernetes
The various components of Kubernetes require certificates in order to authenticate with one another. Provisioning a certificate authority and using it to generate those certificates is a necessary step in bootstrapping a Kubernetes cluster from scratch. This activity will guide you through the process of provisioning a certificate authority and generating the certificates Kubernetes needs.
Path Info
Table of Contents
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Challenge
Provision the certificate authority (CA).
You can provision the certificate authority like so:
{ 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 } -
Challenge
Generate the necessary Kubernetes client certs, as well as kubelet client certs for two worker nodes.
Use these commands to generate the client certs.
Admin client cert:
{ 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 }Kubelet client certs:
{ cat > worker0.mylabserver.com-csr.json << EOF { "CN": "system:node:worker0.mylabserver.com", "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=172.34.1.0,worker0.mylabserver.com -profile=kubernetes worker0.mylabserver.com-csr.json | cfssljson -bare worker0.mylabserver.com cat > worker1.mylabserver.com-csr.json << EOF { "CN": "system:node:worker1.mylabserver.com", "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=172.34.1.1,worker1.mylabserver.com -profile=kubernetes worker1.mylabserver.com-csr.json | cfssljson -bare worker1.mylabserver.com }Kube Controller Manager client cert:
{ 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 }Kube Proxy client cert:
{ 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 }Kube Scheduler client cert:
{ 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 } -
Challenge
Generate the Kubernetes API server certificate.
You can generate the Kubernetes API server certificate like so:
{ 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=10.32.0.1,172.34.0.0,controller0.mylabserver.com,172.34.0.1,controller1.mylabserver.com,172.34.2.0,kubernetes.mylabserver.com,127.0.0.1,localhost,kubernetes.default -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes } -
Challenge
Generate a Kubernetes service account key pair.
To generate the service account key pair, do the following:
{ 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 }
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