// Module included in the following assemblies:
//
// * machine_management/control_plane_machine_management/cpmso-manually-scaling-control-planes.adoc

:_mod-docs-content-type: PROCEDURE
[id="creating-control-plane-node_{context}"]
= Adding a control plane node to your cluster

[role="_abstract"]
Add a control plane node to recover from a degraded state, perform deep-level debugging, or ensure stability and security of the control plane in complex bare metal scenarios. 

.Prerequisites

* You have installed a healthy cluster with at least three control plane nodes.
* You have created a single control plane node that you intend to add to your cluster as a postinstalltion task.

.Procedure

. Retrieve pending Certificate Signing Requests (CSRs) for the new control plane node by entering the following command:
+
[source,terminal]
----
$ oc get csr | grep Pending
----

. Approve all pending CSRs for the control plane node by entering the following command:
+
[source,terminal]
----
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
----
+
[IMPORTANT]
====
You must approve the CSRs to complete the installation.
====

. Confirm that the control plane node is in the `Ready` status by entering the following command:
+
[source,terminal]
----
$ oc get nodes
----
+
[NOTE]
====
On installer-provisioned infrastructure, the etcd Operator relies on the Machine API to manage the control plane and ensure etcd quorum. The Machine API then uses `Machine` CRs to represent and manage the underlying control plane nodes. 
====

. Create the `BareMetalHost` and `Machine` CRs and link them to the `Node` CR of the control plane node.  
+
.. Create the `BareMetalHost` CR with a unique `.metadata.name` value as demonstrated in the following example:
+
[source,yaml]
----
apiVersion: metal3.io/v1alpha1
kind: BareMetalHost
metadata:
  name: node-5
  namespace: openshift-machine-api  
spec:
  automatedCleaningMode: metadata
  bootMACAddress: 00:00:00:00:00:02
  bootMode: UEFI
  customDeploy:
    method: install_coreos
  externallyProvisioned: true
  online: true
  userData:
    name: master-user-data-managed
    namespace: openshift-machine-api
# ...
----
+
.. Apply the `BareMetalHost` CR by entering the following command:
+
[source,terminal]
----
$ oc apply -f <filename>
----
+
where `<filename>` specifies the name of the `BareMetalHost` CR.
+
.. Create the `Machine` CR by using the unique `.metadata.name` value as demonstrated in the following example:
+
[source,yaml]
----
apiVersion: machine.openshift.io/v1beta1
kind: Machine
metadata:
  annotations:
    machine.openshift.io/instance-state: externally provisioned
    metal3.io/BareMetalHost: openshift-machine-api/node-5
  finalizers:
  - machine.machine.openshift.io  
  labels:
    machine.openshift.io/cluster-api-cluster: <cluster_name>
    machine.openshift.io/cluster-api-machine-role: master
    machine.openshift.io/cluster-api-machine-type: master
  name: node-5
  namespace: openshift-machine-api
spec:
  metadata: {}
  providerSpec:
    value:
      apiVersion: baremetal.cluster.k8s.io/v1alpha1
      customDeploy:
        method: install_coreos
      hostSelector: {}
      image:
        checksum: ""
        url: ""
      kind: BareMetalMachineProviderSpec
      metadata:
        creationTimestamp: null
      userData:
        name: master-user-data-managed
# ...
----
+
where `<cluster_name>` specifies the name of the specific cluster, for example, `test-day2-1-6qv96`.
+
.. Get the cluster name by running the following command:
+
[source,terminal]
----
$ oc get infrastructure cluster -o=jsonpath='{.status.infrastructureName}{"\n"}'
----
+
.. Apply the `Machine` CR by entering the following command:
+
[source,terminal]
----
$ oc apply -f <filename>
----
+
where `<filename>` specifies the name of the `Machine` CR.
+
.. Link `BareMetalHost`, `Machine`, and `Node` objects by running the `link-machine-and-node.sh` script:
+
... Copy the following `link-machine-and-node.sh` script to a local machine: 
+
[source,text]
----
#!/bin/bash

# Credit goes to
# https://bugzilla.redhat.com/show_bug.cgi?id=1801238.
# This script will link Machine object
# and Node object. This is needed
# in order to have IP address of
# the Node present in the status of the Machine.

set -e

machine="$1"
node="$2"

if [ -z "$machine" ] || [ -z "$node" ]; then
    echo "Usage: $0 MACHINE NODE"
    exit 1
fi

node_name=$(echo "${node}" | cut -f2 -d':')

oc proxy &
proxy_pid=$!
function kill_proxy {
    kill $proxy_pid
}
trap kill_proxy EXIT SIGINT

HOST_PROXY_API_PATH="http://localhost:8001/apis/metal3.io/v1alpha1/namespaces/openshift-machine-api/baremetalhosts"

function print_nics() {
    local ips
    local eob
    declare -a ips

    readarray -t ips < <(echo "${1}" \
                         | jq '.[] | select(. | .type == "InternalIP") | .address' \
                         | sed 's/"//g')

    eob=','
    for (( i=0; i<${#ips[@]}; i++ )); do
        if [ $((i+1)) -eq ${#ips[@]} ]; then
            eob=""
        fi
        cat <<- EOF
          {
            "ip": "${ips[$i]}",
            "mac": "00:00:00:00:00:00",
            "model": "unknown",
            "speedGbps": 10,
            "vlanId": 0,
            "pxe": true,
            "name": "eth1"
          }${eob}
EOF
    done
}

function wait_for_json() {
    local name
    local url
    local curl_opts
    local timeout

    local start_time
    local curr_time
    local time_diff

    name="$1"
    url="$2"
    timeout="$3"
    shift 3
    curl_opts="$@"
    echo -n "Waiting for $name to respond"
    start_time=$(date +%s)
    until curl -g -X GET "$url" "${curl_opts[@]}" 2> /dev/null | jq '.' 2> /dev/null > /dev/null; do
        echo -n "."
        curr_time=$(date +%s)
        time_diff=$((curr_time - start_time))
        if [[ $time_diff -gt $timeout ]]; then
            printf '\nTimed out waiting for %s' "${name}"
            return 1
        fi
        sleep 5
    done
    echo " Success!"
    return 0
}
wait_for_json oc_proxy "${HOST_PROXY_API_PATH}" 10 -H "Accept: application/json" -H "Content-Type: application/json"

addresses=$(oc get node -n openshift-machine-api "${node_name}" -o json | jq -c '.status.addresses')

machine_data=$(oc get machines.machine.openshift.io -n openshift-machine-api -o json "${machine}")
host=$(echo "$machine_data" | jq '.metadata.annotations["metal3.io/BareMetalHost"]' | cut -f2 -d/ | sed 's/"//g')

if [ -z "$host" ]; then
    echo "Machine $machine is not linked to a host yet." 1>&2
    exit 1
fi

# The address structure on the host doesn't match the node, so extract
# the values we want into separate variables so we can build the patch
# we need.
hostname=$(echo "${addresses}" | jq '.[] | select(. | .type == "Hostname") | .address' | sed 's/"//g')

set +e
read -r -d '' host_patch << EOF
{
  "status": {
    "hardware": {
      "hostname": "${hostname}",
      "nics": [
$(print_nics "${addresses}")
      ],
      "systemVendor": {
        "manufacturer": "Red Hat",
        "productName": "product name",
        "serialNumber": ""
      },
      "firmware": {
        "bios": {
          "date": "04/01/2014",
          "vendor": "SeaBIOS",
          "version": "1.11.0-2.el7"
        }
      },
      "ramMebibytes": 0,
      "storage": [],
      "cpu": {
        "arch": "x86_64",
        "model": "Intel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz",
        "clockMegahertz": 2199.998,
        "count": 4,
        "flags": []
      }
    }
  }
}
EOF
set -e

echo "PATCHING HOST"
echo "${host_patch}" | jq .

curl -s \
     -X PATCH \
     "${HOST_PROXY_API_PATH}/${host}/status" \
     -H "Content-type: application/merge-patch+json" \
     -d "${host_patch}"

oc get baremetalhost -n openshift-machine-api -o yaml "${host}"
----
+
... Make the script executable by entering the following command:
+
[source,terminal]
----
$ chmod +x link-machine-and-node.sh
----
+
... Run the script by entering the following command:
+
[source,terminal]
----
$ bash link-machine-and-node.sh node-5 node-5
----
+
[NOTE]
====
The first `node-5` instance represents the machine, and the second instance represents the node.
====

.Verification

. Confirm members of etcd by executing into one of the pre-existing control plane nodes:
+
.. Open a remote shell session to the control plane node by entering the following command:
+
[source,terminal]
----
$ oc rsh -n openshift-etcd etcd-node-0
----
+
.. List etcd members:
+
[source,terminal]
----
# etcdctl member list -w table
----

. Check the etcd Operator configuration process until completion by entering the following command. Expected output shows `False` under the `PROGRESSING` column.
+
[source,terminal]
----
$ oc get clusteroperator etcd
----

. Confirm etcd health by running the following commands:
+
.. Open a remote shell session to the control plane node:
+
[source,terminal]
----
$ oc rsh -n openshift-etcd etcd-node-0
----
+
.. Check endpoint health. Expected output shows `is healthy` for the endpoint.
+
[source,terminal]
----
# etcdctl endpoint health
----

. Verify that all nodes are ready by entering the following command. The expected output shows the `Ready` status beside each node entry.
+
[source,terminal]
----
$ oc get nodes
----

. Verify that the cluster Operators are all available by entering the following command. Expected output lists each Operator and shows the available status as `True` beside each listed Operator. 
+
[source,terminal]
----
$ oc get ClusterOperators
----

. Verify that the cluster version is correct by entering the following command:
+
[source,terminal]
----
$ oc get ClusterVersion
----
+
.Example output
[source,terminal,subs="attributes+"]]
----
NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version   {product-title}.5    True        False         5h57m   Cluster version is {product-title}.5
----
