When working with OpenLDAP's dynamic configuration (cn=config), the error olcAccess handler exited with 1 typically indicates a syntax validation failure in access control rules. This specific case involves modifying the olcAccess attribute for database {2}hdb.


The error occurs because:
1. The LDIF format may contain invisible characters or incorrect line breaks
2. The access control rule syntax violates OpenLDAP's parsing requirements
3. The modification attempts to replace all existing rules with a single rule without proper incremental changes


Here's the properly formatted LDIF that should work:

dn: olcDatabase={2}hdb,cn=config
changetype: modify
delete: olcAccess
-
add: olcAccess
olcAccess: {0}to *
  by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" write
  by * none

For better reliability, consider using an external file:
# mod_access.ldif
dn: olcDatabase={2}hdb,cn=config
changetype: modify
replace: olcAccess
olcAccess: {0}to *
  by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" write
  by dn.base="cn=admin,dc=example,dc=com" write
  by * none

# Execute with:
ldapmodify -Y EXTERNAL -H ldapi:/// -f mod_access.ldif

1. Enable slapd debug logging:
slapd -d 16383 -h "ldap:/// ldapi:///"
2. Verify configuration syntax:
slaptest -v -f /etc/ldap/slapd.conf
3. Check for hidden characters in your LDIF:
cat -v yourfile.ldif | less
- Missing or extra whitespace after continuation lines

- Incorrect attribute value ordering

- Attempting to modify multiple attributes simultaneously

- Not using proper escaping for special characters
1. Always backup your config before modifications:
ldapsearch -Y EXTERNAL -H ldapi:/// -b cn=config > config_backup.ldif
2. Make incremental changes rather than bulk replacements

3. Test modifications in a staging environment first

4. Consider using configuration management tools like Ansible for reproducible changes



When working with OpenLDAP's dynamic configuration (cn=config), modifying access control rules can sometimes trigger the cryptic error:
ldap_modify: Other (e.g., implementation specific) error (80)
    additional info: <olcAccess> handler exited with 1

This typically occurs when:

The olcAccess syntax contains structural errors
There's a mismatch between the DN format and your LDAP schema
Special characters aren't properly escaped
The access rule violates existing ACL hierarchy

Consider this common attempt that fails:
dn: olcDatabase={2}hdb,cn=config
changetype: modify
replace: olcAccess
olcAccess: {0}to *
 by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" write
 by * none

Solution 1: Proper DN Formatting
dn: olcDatabase={2}hdb,cn=config
changetype: modify
replace: olcAccess
olcAccess: {0}to *
  by dn.base="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" manage
  by * break

Solution 2: Simplified ACL (for testing)
dn: olcDatabase={2}hdb,cn=config
changetype: modify
replace: olcAccess
olcAccess: {0}to *
  by dn.exact="gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth" write
  by anonymous auth
  by * none

Check your slapd logs for more details:
sudo tail -f /var/log/slapd.log
# Or for systemd:
journalctl -u slapd -f

Common log patterns to look for:
acl_parse: line X: unexpected token "X"
acl_parse: invalid DN format
slap_queue_csn: queueing CSN X (X)


Always test ACL changes with ldapmodify -n (dry-run) first
Consider using LDIF files instead of command-line input
Document all ACL changes in version control
Implement gradual rollout with monitoring

For complex ACL setups, consider:
# Multiple discrete access rules:
olcAccess: {0}to dn.subtree="ou=people,dc=example,dc=com"
  by group.exact="cn=admins,ou=groups,dc=example,dc=com" write
  by users read
olcAccess: {1}to attrs=userPassword
  by self =xw
  by anonymous auth
  by * none