check-mk check if hostname and/or ip already exist

we got a script that inserts new hosts in check_mk via curl

#!/bin/bash

cat file.conf | while read line
do

    HOSTNAME=$(echo $line | cut -d '|' -f1)
    IP=$(echo $line | cut -d '|' -f2)


curl "http://myserver/mysite/check_mk/webapi.py?action=add_host&_username=automation&_secret=myautomationsecret" -d 'request={"hostname":"'"$HOSTNAME"'","folder":"ansible","attributes":{"ipaddress":"'"$IP"'","site":"mysite","tag_agent":"cmk-agent"}}'
done

the file "file.conf" is an already processed file from an nmap scan with xmlstarlet, this file does not always have the hostname, therefore the ip address was used as hostname

the file.conf looks like this

192.168.30.1|192.168.30.1|os
_gateway|192.168.30.2|Linux 2.6.18 - 2.6.22
...

so for some hosts the ip address was passed once as hostname and logically as ip. now it is so that an employee enters the correct hostname and deletes the ip from the field hostname

if the above mentioned script is executed again, it will create the host again with the ip as hostname (because no hostname was specified), so now we have the host 2x in check_mk 1x with the manually added hostname and once with the ip as hostname

all other hosts where the hostname was already recognized correctly by nmap from start on were not taken over like it should be

we now need a function that asks for the ip address of the hostname before the script is executed and if it is already there the host should not be created again

with curl you can only get the hosts

curl "http://myserver/mysite/check_mk/webapi.py?action=get_all_hosts&_username=automation&_secret=myautomationsecret"

Solution

First you will need "jq", so apt-get install jq. ( is for reading json file by bash )

FILE="filename"
getHost="http://myserver/mysite/check_mk/webapi.py?action=get_all_host&_username=automation&_secret=myautomationsecret"

  while IFS='|' read -r host ip description
  do

    checkHost=$( curl -s "$getHost" | 
     jq -r '.result | keys[] as $k | "\(.[$k] | .attributes | select(.ipaddress=="'$ip'") | .ipaddress )"' | uniq )

    if [ "$checkHost" != "$ip" ]
    then
            # here you already know that this ip ( $ip ) not exist in check_mk
            # put your curl command with add_host action here
            echo "Hostname: $ip added to check_mk"
    else
            echo "Hostname: $ip is already exist in check_mk"

    fi


  done <$FILE