Added developer script for updating Amazon Route 53

Author: mrog

hack/update_route_53.sh

@@ -0,0 +1,119 @@
+#!/bin/bash
+set -eu
+
+zone_name=
+profile="default"
+
+help() {
+  echo "Continually queries Kubernetes for control plane machines and adds their IP address to an Amazon Route 53"
+  echo "recordset.  The recordset name will be cp, and it will be created in the specified zone.  If a recordset"
+  echo "already exists with that name, it will first be deleted."
+  echo
+  echo "The Route 53 zone has to already exist.  You can create one in the AWS console."
+  echo
+  echo "Before running this script, configure kubectl with the proper kubeconfig and namespace so it can get the"
+  echo "cluster machines."
+  echo
+  echo "This script is not intended for production use."
+  echo
+  echo "USAGE: $0 -z <zone name> [-p <AWS profile name>]"
+}
+
+if [[ $# -eq 0 ]]
+then
+  help
+  exit 2
+fi
+
+short_opts='z:p:h'
+long_opts='zone:,profile:,help'
+parsed_opts=$(getopt 'z:p:h' $*)
+eval set -- $parsed_opts
+
+while true
+do
+  case "$1" in
+    -z)
+      zone_name="$2"
+      shift 2
+      ;;
+    -p)
+      profile="$2"
+      shift 2
+      ;;
+    -h)
+      shift
+      help
+      exit 0
+      ;;
+    --)
+      shift
+      break
+      ;;
+    *)
+      echo "Impossible value found.  This is a bug."
+      exit 1
+      ;;
+  esac
+done
+
+if [[ -z $zone_name ]]
+then
+  echo "Missing zone name"
+  exit 1
+fi
+
+# Zone name must end with a period, but the user doesn't need to know that.  Add one if it's missing.
+if [[ ! $zone_name =~ [.]$ ]]
+then
+  zone_name=$zone_name.
+fi
+
+recordset_name="cp.$zone_name"
+
+zone_id=$(aws route53 list-hosted-zones --profile "$profile" | jq -r '.HostedZones[] | select(.Name == "'"$zone_name"'").Id | split("/")[2]')
+if [[ -n $zone_id ]]
+then
+  echo "Found zone $zone_name"
+else
+  echo "Zone $zone_name not found.  Please create it first."
+  exit 1
+fi
+
+get_recordset() {
+  aws route53 list-resource-record-sets --profile "$profile" --hosted-zone-id "$zone_id" | jq -r '.ResourceRecordSets[] | select(.Name == "'"$recordset_name"'")'
+}
+
+upsert_addresses() {
+  local addresses=$1
+  echo "Replacing old records"
+  local recordset='{"Name":"'"$recordset_name"'","Type":"A","TTL":10,"ResourceRecords":[]}'
+  for address in $addresses
+  do
+    echo "Adding $address"
+    recordset=$(echo "$recordset" | jq -r --arg a "$address" '.ResourceRecords += [{"Value":$a}]')
+  done
+  local batch=$(jq -r -n --argjson rs "$recordset" '{"Changes":[{"Action":"UPSERT","ResourceRecordSet":$rs}]}')
+  aws route53 change-resource-record-sets --profile "$profile" --hosted-zone-id "$zone_id" --change-batch "$batch" > /dev/null
+}
+
+# If the recordset exists from a previous run, delete it.
+old_recordset=$(get_recordset)
+if [[ -n $old_recordset ]]
+then
+  echo "Deleting recordset $recordset_name"
+  aws route53 change-resource-record-sets --profile "$profile" --hosted-zone-id "$zone_id" --change-batch '{"Changes":[{"Action":"DELETE","ResourceRecordSet":'"$old_recordset"'}]}' > /dev/null
+fi
+
+echo "Watching for control plane machines..."
+old_addresses=
+while true
+do
+  addresses=$(kubectl get machine -o json | jq -r '.items[] | select(.metadata.labels."cluster.x-k8s.io/control-plane" != null) | .status | select(.addresses!=null) | .addresses[].address')
+  if [[ $addresses != "$old_addresses" ]]
+  then
+    upsert_addresses "$addresses"
+  fi
+  old_addresses=$addresses
+  sleep 5
+done