Sample ejabberd.yml file. has working ldap connectivity and ldap vcard. works with ejabberd Community Server 16+ maybe older.
###
###'              ejabberd configuration file
###
###

### The parameters used in this configuration file are explained in more detail
### in the ejabberd Installation and Operation Guide.
### Please consult the Guide in case of doubts, it is included with
### your copy of ejabberd, and is also available online at
### http://www.process-one.net/en/ejabberd/docs/

### The configuration file is written in YAML.
### Refer to http://en.wikipedia.org/wiki/YAML for the brief description.
### However, ejabberd treats different literals as different types:
###
### - unquoted or single-quoted strings. They are called "atoms".
###   Example: dog, 'Jupiter', '3.14159', YELLOW
###
### - numeric literals. Example: 3, -45.0, .0
###
### - quoted or folded strings.
###   Examples of quoted string: "Lizzard", "orange".
###   Example of folded string:
###   > Art thou not Romeo,
###     and a Montague?

###.  =======
###'  LOGGING

##
## loglevel: Verbosity of log files generated by ejabberd.
## 0: No ejabberd log at all (not recommended)
## 1: Critical
## 2: Error
## 3: Warning
## 4: Info
## 5: Debug
##
loglevel: 4

##
## rotation: Disable ejabberd's internal log rotation, as the Debian package
## uses logrotate(8).
log_rotate_size: 0
log_rotate_date: ""

##
## overload protection: If you want to limit the number of messages per second
## allowed from error_logger, which is a good idea if you want to avoid a flood
## of messages when system is overloaded, you can set a limit.
## 100 is ejabberd's default.
log_rate_limit: 100

##
## watchdog_admins: Only useful for developers: if an ejabberd process
## consumes a lot of memory, send live notifications to these XMPP
## accounts.
##
## watchdog_admins:
##   - "This email address is being protected from spambots. You need JavaScript enabled to view it."

###.  ===============
###'  NODE PARAMETERS

##
## net_ticktime: Specifies net_kernel tick time in seconds. This options must have
## identical value on all nodes, and in most cases shouldn't be changed at all from
## default value.
##
## net_ticktime: 60

###.  ================
###'  SERVED HOSTNAMES

##
## hosts: Domains served by ejabberd.
## You can define one or several, for example:
## hosts: 
##   - "example.net"
##   - "example.com"
##   - "example.org"
##
hosts:
  - "localhost"
  - "chat"
##
## route_subdomains: Delegate subdomains to other XMPP servers.
## For example, if this ejabberd serves example.org and you want
## to allow communication with an XMPP server called im.example.org.
##
## route_subdomains: s2s

###.  ===============
###'  LISTENING PORTS

##
## listen: The ports ejabberd will listen on, which service each is handled
## by and what options to start it with.
##
listen: 
  - 
    port: 5222
    ip: "::"
    module: ejabberd_c2s
    ##
    ## If TLS is compiled in and you installed a SSL
    ## certificate, specify the full path to the
    ## file and uncomment these lines:
    ##
    certfile: "/etc/ejabberd/ejabberd.pem"
    starttls: true
    ##
    ## To enforce TLS encryption for client connections,
    ## use this instead of the "starttls" option:
    ##
    ## starttls_required: true
    ##
    ## Custom OpenSSL options
    ##
    protocol_options:
      - "no_sslv3"
    ##   - "no_tlsv1"
    max_stanza_size: 65536
    shaper: c2s_shaper
    access: c2s
    zlib: true
    resend_on_timeout: if_offline
  - 
    port: 5269
    ip: "::"
    module: ejabberd_s2s_in
  ##
  ## ejabberd_service: Interact with external components (transports, ...)
  ##
  ## - 
  ##   port: 8888
  ##   module: ejabberd_service
  ##   access: all
  ##   shaper_rule: fast
  ##   ip: "127.0.0.1"
  ##   hosts:
  ##     "icq.example.org":
  ##       password: "secret"
  ##     "sms.example.org":
  ##       password: "secret"

  ##
  ## ejabberd_stun: Handles STUN Binding requests
  ##
  ## - 
  ##   port: 3478
  ##   transport: udp
  ##   module: ejabberd_stun

  ##
  ## To handle XML-RPC requests that provide admin credentials:
  ##
  ## - 
  ##   port: 4560
  ##   module: ejabberd_xmlrpc
  ##   access_commands: {}
  - 
    port: 5280
    ip: "::"
    module: ejabberd_http
    request_handlers:
      "/websocket": ejabberd_http_ws
    ##  "/pub/archive": mod_http_fileserver
    web_admin: true
    http_bind: true
    ## register: true
    mydomaintcha: true
    tls: false
    certfile: "/etc/ejabberd/ejabberd.pem"

## Disabling digest-md5 SASL authentication. digest-md5 requires plain-text
## password storage (see auth_password_format option).
disable_sasl_mechanisms: "digest-md5"

###.  ==================
###'  S2S GLOBAL OPTIONS

##
## s2s_use_starttls: Enable STARTTLS + Dialback for S2S connections.
## Allowed values are: false optional required required_trusted
## You must specify a certificate file.
##
s2s_use_starttls: optional

##
## s2s_certfile: Specify a certificate file.
##
s2s_certfile: "/etc/ejabberd/ejabberd.pem"

## Custom OpenSSL options
##
s2s_protocol_options:
  - "no_sslv3"
##   - "no_tlsv1"

##
## domain_certfile: Specify a different certificate for each served hostname.
##
## host_config:
##   "example.org":
##     domain_certfile: "/path/to/example_org.pem"
##   "example.com":
##     domain_certfile: "/path/to/example_com.pem"

##
## S2S whitelist or blacklist
##
## Default s2s policy for undefined hosts.
##
## s2s_access: s2s

##
## Outgoing S2S options
##
## Preferred address families (which to try first) and connect timeout
## in milliseconds.
##
## outgoing_s2s_families:
##   - ipv4
##   - ipv6
## outgoing_s2s_timeout: 10000

###.  ==============
###'  AUTHENTICATION

##
## auth_method: Method used to authenticate the users.
## The default method is the internal.
## If you want to use a different method,
## comment this line and enable the correct ones.
##
##auth_method: internal

##
## Store the plain passwords or hashed for SCRAM:
## auth_password_format: plain
##auth_password_format: scram
##
## Define the FQDN if ejabberd doesn't detect it:
## fqdn: "server3.example.com"

##
## Authentication using external script
## Make sure the script is executable by ejabberd.
##
## auth_method: external
## extauth_program: "/path/to/authentication/script"

##
## Authentication using ODBC
## Remember to setup a database in the next section.
##
## auth_method: odbc

##
## Authentication using PAM
##
## auth_method: pam
## pam_service: "pamservicename"

##
## Authentication using LDAP
##
##auth_method: ldap
##
## List of LDAP servers:
##ldap_servers:
##   - "192.168.5.55"
##   - "192.168.5.56"
##
## Encryption of connection to LDAP servers:
##ldap_encrypt: none
##ldap_encrypt: tls
##
## Port to connect to on LDAP servers:
##ldap_port: 389
##ldap_port: 636
##
## LDAP manager:
##ldap_rootdn: "CN=LDAP Service,OU=mydomain Users,DC=mydomain,DC=local"
##ldap_rootdn: "CN=LDAP Service"
##
## Password of LDAP manager:
##ldap_password: "M@na93d4DAcc0unt"
##
## Search base of LDAP directory:
## ldap_base: "OU=mydomain Users"
##
## LDAP attribute that holds user ID:
##ldap_uids: 
##   - "sAMAccountName": "%u"
##
## LDAP filter:
##ldap_filter: "(memberOf=*)"

auth_method: [ldap]
ldap_servers:   
   - "192.168.1.2"
   - "192.168.1.3"
ldap_base: "OU=mydomain Users,DC=mydomain,DC=local" 
ldap_rootdn: "CN=LDAP Service,OU=mydomain Users,DC=mydomain,DC=local"
ldap_password: "AcPassw0rd!" 
ldap_uids: ["sAMAccountName"]
ldap_filter: "(memberOf=*)"	








##
## Anonymous login support:
##   auth_method: anonymous
##   anonymous_protocol: sasl_anon | login_anon | both
##   allow_multiple_connections: true | false
##
## host_config:
##   "public.example.org":
##     auth_method: anonymous
##     allow_multiple_connections: false
##     anonymous_protocol: sasl_anon
##
## To use both anonymous and internal authentication:
##
## host_config:
##   "public.example.org":
##     auth_method:
##       - internal
##       - anonymous

###.  ==============
###'  DATABASE SETUP

## ejabberd by default uses the internal Mnesia database,
## so you do not necessarily need this section.
## This section provides configuration examples in case
## you want to use other database backends.
## Please consult the ejabberd Guide for details on database creation.

##
## MySQL server:
##
## odbc_type: mysql
## odbc_server: "server"
## odbc_database: "database"
## odbc_username: "username"
## odbc_password: "password"
##
## If you want to specify the port:
## odbc_port: 1234

##
## PostgreSQL server:
##
## odbc_type: pgsql
## odbc_server: "server"
## odbc_database: "database"
## odbc_username: "username"
## odbc_password: "password"
##
## If you want to specify the port:
## odbc_port: 1234
##
## If you use PostgreSQL, have a large database, and need a
## faster but inexact replacement for "select count(*) from users"
##
## pgsql_users_number_estimate: true

##
## SQLite:
##
## odbc_type: sqlite
## odbc_database: "/path/to/database.db"

##
## ODBC compatible or MSSQL server:
##
## odbc_type: odbc
## odbc_server: "DSN=ejabberd;UID=ejabberd;PWD=ejabberd"

##
## Number of connections to open to the database for each virtual host
##
## odbc_pool_size: 10

##
## Interval to make a dummy SQL request to keep the connections to the
## database alive. Specify in seconds: for example 28800 means 8 hours
##
## odbc_keepalive_interval: undefined

###.  ===============
###'  TRAFFIC SHAPERS

shaper:
  ##
  ## The "normal" shaper limits traffic speed to 1000 B/s
  ##
  normal: 1000

  ##
  ## The "fast" shaper limits traffic speed to 50000 B/s
  ##
  fast: 50000

##
## This option specifies the maximum number of elements in the queue
## of the FSM. Refer to the documentation for details.
##
max_fsm_queue: 1000

###.   ====================
###'   ACCESS CONTROL LISTS
acl:
  ##
  ## The 'admin' ACL grants administrative privileges to XMPP accounts.
  ## You can put here as many accounts as you want.
  ##
  admin:
     user:
         - "": "localhost"
     user:
         - "mell": "chat"
     user:
         - "admin": "chat"

  ##
  ## Blocked users
  ##
  ## blocked:
  ##   user:
  ##     - "baduser": "example.org"
  ##     - "test"

  ## Local users: don't modify this.
  ##
  local: 
    user_regexp: ""

  ##
  ## More examples of ACLs
  ##
  ## jabberorg:
  ##   server:
  ##     - "jabber.org"
  ## aleksey:
  ##   user:
  ##     - "aleksey": "jabber.ru"
  ## test:
  ##   user_regexp: "^test"
  ##   user_glob: "test*"

  ##
  ## Loopback network
  ##
  loopback:
    ip:
      - "127.0.0.0/8"

  ##
  ## Bad XMPP servers
  ##
  ## bad_servers:
  ##   server:
  ##     - "xmpp.zombie.org"
  ##     - "xmpp.spam.com"

##
## Define specific ACLs in a virtual host.
##
## host_config:
##   "localhost":
##     acl:
##       admin:
##         user:
##           - "bob-local": "localhost"

###.  ============
###'  ACCESS RULES
access:
  ## Maximum number of simultaneous sessions allowed for a single user:
  max_user_sessions: 
    all: 10
  ## Maximum number of offline messages that users can have:
  max_user_offline_messages: 
    admin: 5000
    all: 100
  ## This rule allows access only for local users:
  local: 
    local: allow
  ## Only non-blocked users can use c2s connections:
  c2s: 
    blocked: deny
    all: allow
  ## For C2S connections, all users except admins use the "normal" shaper
  c2s_shaper: 
    admin: none
    all: normal
  ## All S2S connections use the "fast" shaper
  s2s_shaper: 
    all: fast
  ## Only admins can send announcement messages:
  announce: 
    admin: allow
  ## Only admins can use the configuration interface:
  configure: 
    admin: allow
  ## Admins of this server are also admins of the MUC service:
  muc_admin: 
    admin: allow
  ## Only accounts of the local ejabberd server can create rooms:
  muc_create: 
    local: allow
  ## All users are allowed to use the MUC service:
  muc: 
    all: allow
  ## Only accounts on the local ejabberd server can create Pubsub nodes:
  pubsub_createnode: 
    local: allow
  ## In-band registration allows registration of any possible username.
  ## To disable in-band registration, replace 'allow' with 'deny'.
  register: 
    all: allow
  ## Only allow to register from localhost
  trusted_network: 
    loopback: allow
  ## Do not establish S2S connections with bad servers
  ## s2s: 
  ##   bad_servers: deny
  ##   all: allow

## By default the frequency of account registrations from the same IP
## is limited to 1 account every 10 minutes. To disable, specify: infinity
## registration_timeout: 600
  
##
## Define specific Access Rules in a virtual host.
##
## host_config:
##   "localhost":
##     access:
##       c2s:
##         admin: allow
##         all: deny
##       register:
##         all: deny

###.  ================
###'  DEFAULT LANGUAGE

##
## language: Default language used for server messages.
##
language: "en"

##
## Set a different default language in a virtual host.
##
## host_config:
##   "localhost":
##     language: "ru"

###.  =======
###'  mydomainTCHA

##
## Full path to a script that generates the image.
##
## mydomaintcha_cmd: "/usr/share/ejabberd/mydomaintcha.sh"

##
## Host for the URL and port where ejabberd listens for mydomainTCHA requests.
##
## mydomaintcha_host: "example.org:5280"

##
## Limit mydomainTCHA calls per minute for JID/IP to avoid DoS.
##
## mydomaintcha_limit: 5

###.  =======
###'  MODULES

##
## Modules enabled in all ejabberd virtual hosts.
##
modules: 
  mod_adhoc: {}
  mod_admin_extra: {}
  mod_announce: # recommends mod_adhoc
    access: announce
  mod_blocking: {} # requires mod_privacy
  mod_mydomains: {}
  mod_carboncopy: {}
  mod_client_state: {}
  mod_configure: {} # requires mod_adhoc
  mod_disco: {}
  mod_echo: {}
  mod_irc: {}
  mod_http_bind: {}
  ## mod_http_fileserver:
  ##   docroot: "/var/www"
  ##   accesslog: "/var/log/ejabberd/access.log"
  mod_last: {}
  mod_muc: 
    ## host: "conference.@HOST@"
    access: muc
    access_create: muc_create
    access_persistent: muc_create
    access_admin: muc_admin
  ## mod_muc_log: {}
  mod_muc_admin: {}
  ## mod_multicast: {}
  mod_offline: 
    access_max_user_messages: max_user_offline_messages
  mod_ping: {}
  ## mod_pres_counter:
  ##   count: 5
  ##   interval: 60
  mod_privacy: {}
  mod_private: {}
  ## mod_proxy65: {}
  mod_pubsub: 
    access_createnode: pubsub_createnode
    ## reduces resource comsumption, but XEP incompliant
    ignore_pep_from_offline: true
    ## XEP compliant, but increases resource comsumption
    ## ignore_pep_from_offline: false
    last_item_cache: false
    plugins: 
      - "flat"
      - "hometree"
      - "pep" # pep requires mod_mydomains
  mod_register: 
    ##
    ## Protect In-Band account registrations with mydomainTCHA.
    ##
    ## mydomaintcha_protected: true

    ##
    ## Set the minimum informational entropy for passwords.
    ##
    ## password_strength: 32

    ##
    ## After successful registration, the user receives
    ## a message with this subject and body.
    ##
    welcome_message: 
      subject: "Welcome!"
      body: |-
        Hi.
        Welcome to this XMPP server.

    ##
    ## When a user registers, send a notification to
    ## these XMPP accounts.
    ##
    ## registration_watchers:
    ##   - "This email address is being protected from spambots. You need JavaScript enabled to view it."

    ##
    ## Only clients in the server machine can register accounts
    ##
    ip_access: trusted_network

    ##
    ## Local c2s or remote s2s users cannot register accounts
    ##
    ## access_from: deny

    access: register
  mod_roster: {}
  mod_shared_roster: {}
  mod_stats: {}
  mod_time: {}
  mod_vcard:
    search: false
  mod_vcard_ldap:
    ldap_rootdn: "CN=LDAP Service,OU=mydomain Users,DC=mydomain,DC=local"
    ldap_password: "AcPassw0rd!"
    ldap_base: "OU=mydomain Users,DC=mydomain,DC=local"
    ldap_uids:
         "userPrincipalName": "%This email address is being protected from spambots. You need JavaScript enabled to view it."    
    ldap_vcard_map:
      "FN": {"%s": ["displayName"]}
      "EMAIL": {"%This email address is being protected from spambots. You need JavaScript enabled to view it.": ["sAMAccountName"]}
      "TITLE": {"%s": ["title"]}
      "DESC": {"%s": ["description"]}
      "TEL": {"%s": ["telephoneNumber"]}
      "PHOTO": {"%s": ["jpegPhoto"]}
    ldap_search_fields:
      "User": "%u"
      "Name": "givenName"
      "Family Name": "sn"
      "Email": "mail"
    ldap_search_reported:
      "Full Name": "FN"
      "Email": "EMAIL"

##
## Enable modules with custom options in a specific virtual host
##
## host_config:
##   "localhost":
##     modules:
##       mod_echo:
##         host: "mirror.localhost"

##
## Enable modules management via ejabberdctl for installation and
## uninstallation of public/private contributed modules
## (enabled by default)
##

allow_contrib_modules: true

###.
###'
### Local Variables:
### mode: yaml
### End:
### vim: set filetype=yaml tabstop=8 foldmarker=###',###. foldmethod=marker:


REF: https://www.process-one.net/en/ejabberd/#getejabberd