consul-api-demo works incorrectly

[Will Tang]

The script.sh doesn't work as expected. When servers no longer exist in Consul they can't be removed from the upstream of NGINX.
I modified the script to the below the problem was solved.

#!/bin/bash
if [[ -z "$HOST_IP" ]]; then
  echo "HOST_IP not set in consul container. Setting it to 10.1.10.227 (IP address assigned in the Vagrantfile)"
  HOST_IP=10.1.10.227
fi

CURL='/usr/bin/curl'
OPTIONS='-s'
CONSUL_SERVICES_API="http://$HOST_IP:8500/v1/catalog/services"
CONSUL_SERVICE_API="http://$HOST_IP:8500/v1/catalog/service"
STATUS_UPSTREAMS_API="http://$HOST_IP:8080/api/3/http/upstreams"

# Get the list of current NGINX upstreams
upstreams=$($CURL $OPTIONS $STATUS_UPSTREAMS_API | jq -r '. as $in | keys[]')
servers=$($CURL $OPTIONS ${STATUS_UPSTREAMS_API}/${upstreams}/servers)
echo "NGINX upstreams in $upstreams:"
echo $servers

# Loop through the registered servers in consul tagged with production (i.e backend servers to be proxied through nginx) and add the ones not present in the Nginx upstream block
service=$($CURL $OPTIONS $CONSUL_SERVICES_API | jq --raw-output 'to_entries | .[] | select(.value[0] == "production") | .key')
echo "Servers registered with consul:"
echo $service

ports=$($CURL $OPTIONS $CONSUL_SERVICE_API/$service | jq -r '.[] | .ServicePort')
for port in ${ports[@]}; do
  entry=$HOST_IP:$port
  if [[ ! $servers =~ $entry ]]; then
    $CURL -X POST -d '{"server": "'$entry'"}' $OPTIONS "${STATUS_UPSTREAMS_API}/${upstreams}/servers"
    echo "Added $entry to the NGINX upstream group $upstreams!"
  fi
done

# Loop through the NGINX upstreams and remove the ones not present in consul
servers=($($CURL $OPTIONS ${STATUS_UPSTREAMS_API}/${upstreams}/servers | jq  -c '.[]'))
for params in ${servers[@]}; do
# Here is the block I modified!
  if [[ $params =~ "server" ]]; then
    server=$(echo $params | jq '.server')
    id=$(echo $params | jq '.id')
# Modification end!
  else
    continue
  fi

  service=$($CURL $OPTIONS $CONSUL_SERVICES_API | jq --raw-output 'to_entries| .[] | select(.value[0] == "production") | .key')
  ports=$($CURL $OPTIONS $CONSUL_SERVICE_API/$service | jq -r '.[]|.ServicePort')
  found=0
  for port in ${ports[@]}; do
    entry=$HOST_IP:$port
    if [[ $server =~ $entry ]]; then
      echo "$server matches consul entry $entry"
      found=1
      break
    else
      continue
    fi
  done

  if [ $found -eq 0 ]; then
    $CURL -X DELETE $OPTIONS "{$STATUS_UPSTREAMS_API}/$upstreams/servers/$id"
    echo "Removed $server # $id from nginx upstream block $upstreams!"
  fi
done