OpenLDAP

OpenLDAP 2.6 container running on Ubuntu 26.04 with cn=config (slapd-config) database.

Optional Bootstrap Accounts CSV Files

Bootstrap reads account files from /bootstrap/accounts inside the container.

With the current compose setup, this maps to:

~/app-data/openldap/accounts

Optional files:

• users.csv: uid,gn,sn,mail
• admins.csv: uid,gn,sn,mail
• posix-users.csv: uid,gn,sn,mail,uidNumber,gidNumber

You can provide any subset of these files; missing files are skipped.

Rows starting with # are ignored.

Changing the password

Use ldappasswd to change the password:

BASE_DN="dc=koszewscy,dc=waw,dc=pl"
USER_DN="cn=admin,$BASE_DN"
ldappasswd -x -D "$USER_DN" -W -S "$USER_DN"

or use a oneliner:

DN="cn=admin,dc=koszewscy,dc=waw,dc=pl" ldappasswd -x -D "$DN" -W -S "$DN"

Change the password for the Admin:

change_password.ldif:

dn: olcDatabase={1}mdb,cn=config
changetype: modify
replace: olcRootPW
olcRootPW: {SSHA}newhashedpassword

ldapmodify -Q -Y EXTERNAL -H ldapi:/// -f change_password.ldif

LDIF file format

The basic form of an entry is:

# comment
dn: <distinguished name>
<attrdesc>: <attrvalue>
<attrdesc>: <attrvalue>

...

Lines may be continued by starting the next line with a single space or tab.

dn: cn=Barbara J Jensen,dc=example,dc=
  com
cn: Barbara J
  Jensen

is equivalent to:

dn: cn=Barbara J Jensen,dc=example,dc=com
cn: Barbara J Jensen

Multiple values for the same attribute are represented by repeating the attribute description:

dn: cn=Barbara J Jensen,dc=example,dc=com
cn: Barbara J Jensen
cn: Babs Jensen

If an attribute value contains a non-printable character, it must be base64-encoded and prefixed with a single colon:

dn: cn=Barbara J Jensen,dc=example,dc=com
cn:: QmFyYmFyYSBKIEplbnNlbgo=

Binary files (e.g. images) can be included in the LDIF file by using the "file:" prefix:

dn: cn=Barbara J Jensen,dc=example,dc=com
jpegPhoto:< file:///home/bjensen/photo.jpg

Multiple entries are separated by a blank line. Binary files like the one above may also be included in as Base64-encoded values.

The full specification is available at https://datatracker.ietf.org/doc/html/rfc2849.

Accessing cn=config

SASL EXTERNAL authenticates via the Unix socket — uid=0 maps to the cn=config superuser. The commands must run inside the container where the socket is accessible.

Browse the entire cn=config tree

ldapsearch -Q -Y EXTERNAL -H ldapi:/// -b cn=config

Browse a specific database entry

ldapsearch -Q -Y EXTERNAL -H ldapi:/// -b "olcDatabase={1}mdb,cn=config"

Modify cn=config

ldapmodify -Q -Y EXTERNAL -H ldapi:/// <<'EOF'
dn: cn=config
changetype: modify
replace: olcLogLevel
olcLogLevel: stats
EOF

Verify EXTERNAL identity

ldapwhoami -Q -Y EXTERNAL -H ldapi:///

Expected: dn:gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth

Editing Access Control Rules

1. Inserting a New Rule at the Top

# filename: insert_rule.ldif  
dn: olcDatabase={1}mdb,cn=config  
changetype: modify  
add: olcAccess  
olcAccess: {0}to *
  by dn.exact="cn=security-scanner,dc=example,dc=com" read break

2. Deleting a Specific Rule

# filename: delete_rule.ldif  
dn: olcDatabase={1}mdb,cn=config  
changetype: modify  
delete: olcAccess  
olcAccess: {2}

3. Updating an Existing Rule (In-Place)

# filename: update_rule.ldif  
dn: olcDatabase={1}mdb,cn=config  
changetype: modify  
replace: olcAccess  
olcAccess: {1}to attrs=userPassword
  by self write
  by anonymous auth
  by group.exact="cn=it-admins,dc=example,dc=com" write

4. Reordering the Entire Stack

# filename: reorder_rules.ldif
dn: olcDatabase={1}mdb,cn=config
changetype: modify
replace: olcAccess
olcAccess: {0}to *
  by dn.exact="cn=security-scanner,dc=example,dc=com" read break
olcAccess: {1}to attrs=userPassword
  by self write
  by anonymous auth
  by group.exact="cn=it-admins,dc=example,dc=com" write
olcAccess: {2}to *
  by self read

Accessing the DIT

ldapsearch -x -H ldap://localhost \
  -D "cn=admin,dc=koszewscy,dc=waw,dc=pl" -W \
  -b "dc=koszewscy,dc=waw,dc=pl"

Verify readonly service account bind

ldapwhoami -x -H ldap://localhost \
  -D "cn=readonly,ou=service-accounts,dc=koszewscy,dc=waw,dc=pl" -W