Simple bash check was created:
result=$(/bin/ldapsearch -H ldaps://ldapserver.local -b "dc=domain, dc=local" "(&(objectClass=group)(cn=IT.Group))" -x
-D "CN=ldap-svc-account,OU=Service accounts,OU=Accounts,DC=dmz,DC=domain,DC=local"
-w 'pA$$w0rd' | grep "member:" -c)
echo "Statistic: $result"
I'm using -w flag to provide a password for simple authentication.
This check starts from the linux host 'monserver.local' under the user 'mon-svc-acc':

How to avoid keeping ldap password (pA$$w0rd) in plaintext?
Can I use ${PASSWORD} or ${CREDENTIAL} variable somehow?