checkmk docker containers as hosts

#!/bin/bash

# parameters needed to be set site-specific.
SERVER_IP="172.25.17.3"
SITE_NAME="cmk" # More infos: https://docs.checkmk.com/latest/de/intro_setup.html#create_site
API_URL="http://$SERVER_IP/$SITE_NAME/check_mk/api/1.0"
USERNAME="automation"
PASSWORD="<PASSWORD_OF_THE_AUTOMATION_USER>"
FOLDER="/docker_container" # (Optional) More infos: https://docs.checkmk.com/latest/de/hosts_structure.html?#folder
# End specific parameters
##### below should not be changed unless you are absolutely sure in what you are doing !

# Check if there are any pending changes on the checkmk server
temp_file=$(mktemp)
# Get Content-Length from "pending changes" object via REST-API
curl -s -S -I -H "Authorization: Bearer $USERNAME $PASSWORD" -X GET "$API_URL/domain-types/activation_run/collections/pending_changes" > "$temp_file" 2> error.log &
printf "\n\n\nGet Content-Length from 'pending changes' object via REST-API\n"
# Extract the ETag value from the file content
result=$(grep -iE '^Content-Length: ' "$temp_file" | awk '{print $2}' | tr -d '"' | tr -cd '[:alnum:]')
# Delete the temporary file
rm "$temp_file"
if [ "$result" -gt 350 ]; then
 printf "$(tput setaf 1)%s$(tput sgr0)\n" "Please revert or accept pending change(s) on the checkmk server before running the script! Install aborted!"
 exit
fi

# Iterate over subfolders (recursive depth 1). Remove folder(s) and host(s) if the folder(s) are last modified time is older than 60 min
subfolders_old=$(find /omd/sites/$SITE_NAME/tmp/check_mk/piggyback -maxdepth 1 -type d -mmin +60 -exec basename {} \; | grep -E '^[0-9a-f]{12}$')
for subfolder_old in $subfolders_old; do
  rm -r /omd/sites/$SITE_NAME/tmp/check_mk/piggyback/$subfolder_old

  # Delete Host via REST-API
  printf "\n\n\nDelete host: $subfolder_old via REST_API\n\n"
  curloutput=$(curl -s -S -H "Accept: application/json" -H "Authorization: Bearer $USERNAME $PASSWORD" -X DELETE -H "Content-Type: application/json" "$API_URL/objects/host_config/$subfolder_old")
  sleep 1

  echo $curloutput | grep -q "Host not found"
  if [ $? -ne 0 ]; then
  # Get ETag from "pending changes" object via REST-API
  temp_file=$(mktemp)
  curl -s -S -I -H "Authorization: Bearer $USERNAME $PASSWORD" -X GET "$API_URL/domain-types/activation_run/collections/pending_changes" 1> "$temp_file"
  printf "\n\n\nGet ETag from 'pending changes' object via REST-API\n\n"
  # Extract the ETag value from the file content
  etag=$(grep -iE '^ETag: ' "$temp_file" | awk '{print $2}' | tr -d '"' | tr -cd '[:alnum:]')
  rm "$temp_file"
  sleep 1

  # Start activating the pending changes via REST-API
  temp_file=$(mktemp)
  BODY="{\"force_foreign_changes\": \"false\", \"redirect\": \"false\", \"sites\": [\"$SITE_NAME\"]}"
  curl -s -S -H "Accept: application/json" -H "Authorization: Bearer $USERNAME $PASSWORD" -H "If-Match: \"$etag\"" -X POST -H "Content-Type: application/json" -d "$BODY" "$API_URL/domain-types/activation_run/actions/activate-changes/invoke"  1> "$temp_file"
  printf "\n\n\nStart activating the pending changes via REST-API\n\n"
  # Extract the id value from the file content
  activation_id=$(cat $temp_file | grep -oP '(?<="id": ")[^"]+' | head -n1)
  rm "$temp_file"
  sleep 60
  fi

  printf "\n\n\n##################################################"
done

# Iterate over subfolders (recursive depth 1). Create host(s) after folder name(s)
subfolders=$(find /omd/sites/$SITE_NAME/tmp/check_mk/piggyback -maxdepth 1 -type d -exec basename {} \; | grep -E '^[0-9a-f]{12}$')
for subfolder in $subfolders; do
  # Get file name inside the folder
  file=$(find "/omd/sites/$SITE_NAME/tmp/check_mk/piggyback/$subfolder" -type f -print -quit)

  # Get docker host machine name
  dockerhostname=$(basename $file)

  # Use the ImageTag value as an alias name for the new host
  hostalias=$(grep -o '"ImageTags": \[[^]]*\]' "$file" | awk -F '[][]' '{gsub(/"/, "", $2); split($2, arr, ":"); print arr[1]}')

  # Create Host via REST-API
  printf "\n\n\nCreate host: $subfolder via REST_API\n\n"
  BODY="{\"folder\": \"$FOLDER\", \"host_name\": \"$subfolder\", \"attributes\": {\"alias\": \"$hostalias\", \"labels\": {\"$dockerhostname\": \"$hostalias\"}}}"
  curloutput=$(curl -s -S -H "Accept: application/json" -H "Authorization: Bearer $USERNAME $PASSWORD" -X POST -H "Content-Type: application/json" -d "$BODY" "$API_URL/domain-types/host_config/collections/all")
  sleep 1

  echo $curloutput | grep -q "already exists"
  if [ $? -ne 0 ]; then
     # Get ETag from "pending changes" object via REST-API
     temp_file=$(mktemp)
     curl -s -S -I -H "Authorization: Bearer $USERNAME $PASSWORD" -X GET "$API_URL/domain-types/activation_run/collections/pending_changes" 1> "$temp_file"
     printf "\n\n\nGet ETag from 'pending changes' object via REST-API\n\n"
     # Extract the ETag value from the file content
     etag=$(grep -iE '^ETag: ' "$temp_file" | awk '{print $2}' | tr -d '"' | tr -cd '[:alnum:]')
     rm "$temp_file"
     sleep 1

     # Start activating the pending changes via REST-API
     temp_file=$(mktemp)
     BODY="{\"force_foreign_changes\": \"false\", \"redirect\": \"false\", \"sites\": [\"$SITE_NAME\"]}"
     curl -s -S -H "Accept: application/json" -H "Authorization: Bearer $USERNAME $PASSWORD" -H "If-Match: \"$etag\"" -X POST -H "Content-Type: application/json" -d "$BODY" "$API_URL/domain-types/activation_run/actions/activate-changes/invoke"  1> "$temp_file"
     printf "\n\n\nStart activating the pending changes via REST-API\n\n"
     # Extract the id value from the file content
     activation_id=$(cat $temp_file | grep -oP '(?<="id": ")[^"]+' | head -n1)
     rm "$temp_file"
     sleep 60
   fi

   printf "\n\n\n##################################################"
done