lloadd — LDAP Load Balancer Daemon
LIBEXECDIR/lloadd [
−4 | −6 ] [ −d debug−level ] [ −f lloadd−config−file ] [
−h URLs ] [ −n service−name ] [
−s syslog−level ] [
−l
syslog−local−user ] [ −o option[= value] ] [ −r directory ] [ −u user ] [ −g group ]
Lloadd is the
stand-alone LDAP daemon. It listens for LDAP connections on
any number of ports (default 389), forwarding the LDAP operations it
receives over these connections to be handled by the
configured backends. lloadd is typically invoked
at boot time, usually out of /etc/rc.local. Upon startup, lloadd normally forks and
disassociates itself from the invoking tty. If configured in
the config file, the lloadd process will print its
process ID (see getpid(2)) to a .pid file, as well as the
command line options during invocation to an .args file (see lloadd.conf(5)). If the
−d flag is given, even with
a zero argument, lloadd will not fork and
disassociate from the invoking tty.
See the "OpenLDAP Administrator's Guide" for more details on lloadd.
−4Listen on IPv4 addresses only.
−6Listen on IPv6 addresses only.
−d
debug−levelTurn on debugging as defined by debug-level. If this
option is specified, even with a zero argument,
lloadd will
not fork or disassociate from the invoking terminal.
Some general operation and status messages are printed
for any value of debug-level. debug-level is taken as a
bit string, with each bit corresponding to a different
kind of debugging information. See <ldap_log.h>
for details. Comma-separated arrays of friendly names
can be specified to select debugging output of the
corresponding debugging information. All the names
recognized by the loglevel directive
described in lloadd.conf(5) are
supported. If debug-level is
?, a list of installed
debug-levels is printed, and lloadd exits.
Remember that if you turn on packet logging, packets containing bind passwords will be output, so if you redirect the log to a logfile, that file should be read-protected.
−s
syslog−levelThis option tells lloadd at what
debug-level debugging statements should be logged to
the syslog(8) facility. The
value syslog-level can be set
to any value or combination allowed by the −d switch. Lloadd logs all
messages selected by syslog-level at the
syslog(3) severity
debug-level DEBUG, on the
unit specified with −l.
−n
service−nameSpecifies the service name for logging and other purposes. Defaults to basename of argv[0], i.e.: "lloadd".
−l
syslog−local−userSelects the local user of the syslog(8) facility. Value
can be LOCAL0, through
LOCAL7, as well as
USER and DAEMON. The default is LOCAL4. However, this option is only
permitted on systems that support local users with the
syslog(8) facility.
Logging to syslog(8) occurs at the "DEBUG" severity
debug-level.
−f
lloadd−config−fileSpecifies the lloadd configuration file. The default
is ETCDIR/lloadd.conf.
−h
URLlistlloadd
will by default serve ldap:/// (LDAP over TCP
on all interfaces on default LDAP port). That is, it
will bind using INADDR_ANY and port 389. The −h option may be used to specify
LDAP (and other scheme) URLs to serve. For example, if
lloadd is given −h
"ldap://127.0.0.1:9009/ ldaps:/// ldapi:///", it
will listen on 127.0.0.1:9009 for LDAP, 0.0.0.0:636 for
LDAP over TLS, and LDAP over IPC (Unix domain sockets).
Host 0.0.0.0 represents INADDR_ANY (any interface). A
space separated list of URLs is expected. The URLs
should be of the LDAP, PLDAP, LDAPS, PLDAPS, or LDAPI
schemes, and generally without a DN or other optional
parameters (excepting as discussed below). Support for
the latter three schemes depends on selected
configuration options. Hosts may be specified by name
or IPv4 and IPv6 address formats. Ports, if specified,
must be numeric. The default ldap:// port is
389 and the default
ldaps:// port is 636,
same for the proxy enabled variants.
The PLDAP and PLDAPS URL schemes provide support for the HAProxy proxy protocol version 2, which allows a load balancer or proxy server to provide the remote client IP address to slapd to be used for access control or logging. Ports configured for PLDAP or PLDAPS will only accept connections that include the necessary proxy protocol header. Connections to these ports should be restricted at the network level to only trusted load balancers or proxies to avoid spoofing of client IP addresses by third parties.
At the moment, the load balancer does not act on the recorded address in any way.
For LDAP over IPC, name is the name of the
socket, and no port is required, nor
allowed; note that directory separators must be
URL-encoded, like any other characters that are special
to URLs; so the socket
/usr/local/var/ldapi
must be specified as
ldapi://%2Fusr%2Flocal%2Fvar%2Fldapi
The default location for the IPC socket is LOCALSTATEDIR/run/ldapi
−r
directorySpecifies a directory to become the root directory.
lloadd will change the current working directory to
this directory and then chroot(2) to this
directory. This is done after opening listeners but
before reading any configuration file or initializing
any backend. When used as a security mechanism, it
should be used in conjunction with −u and −g options.
−u
userlloadd
will run lloadd with the specified user name or id, and
that user's supplementary group access list as set with
initgroups(3). The group ID is also changed to this
user's gid, unless the −g option is used to override.
Note when used with −r, lloadd will use the user
database in the change root environment.
−g
grouplloadd
will run with the specified group name or id. Note when
used with −r, lloadd
will use the group database in the change root
environment.
−o
option[=value]This option provides a generic means to specify options without the need to reserve a separate letter for them.
It supports the following options:
slp={on|off|}slp-attrsWhen SLP support is compiled into lloadd, disable it (off), enable it by registering at SLP DAs without specific SLP attributes (on), or with specific SLP attributes
slp-attrsthat must be an SLP attribute list definition according to the SLP standard.For example,
"slp=(tree=production),(server-type=OpenLDAP),(server−version=2.4.15)"registers at SLP DAs with the three SLP attributes tree, server-type and server-version that have the values given above. This allows one to specifically query the SLP DAs for LDAP servers holding theproductiontree in case multiple trees are available.
Lloadd can be
compiled as a slapd
loadable module. In that case, it can be loaded as such:
moduleload path/to/lloadd.la
backend lload
listen "listening URLs"
This enables lloadd to provide additional
features through the host slapd process like access to
run-time statistics in cn=monitor and dynamic
configuration from cn=config.
The listening sockets specified will be under direct
control of lloadd
and need to be different from the sockets slapd is configured
to listen on. Clients connecting to these are completely
separate from regular LDAP clients connecting to the usual
slapd sockets -
lloadd clients have
no access to slapd databases, similarly, slapd client traffic does not
propagate to the lloadd backend servers in any
way.
To start lloadd
and have it fork and detach from the terminal and start
load-balancing the LDAP servers defined in the default config
file, just type:
LIBEXECDIR/lloadd
To start lloadd
with an alternate configuration file, and turn on voluminous
debugging which will be printed on standard error, type:
LIBEXECDIR/lloadd −f /var/tmp/lloadd.conf −d 255
To start lloadd
as a module inside a slapd process listening on ldap://:1389
and ldaps://, put the following in your slapd.conf (or its
equivalent in cn=config):
moduleload lloadd.la
backend lload
listen "ldap://:1389 ldaps://"
ldap(3), lloadd.conf(5), slapd-config(5), slapd-monitor(5), slapd(8).
"OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)
OpenLDAP Software is developed and maintained by The OpenLDAP Project <http://www.openldap.org/>. OpenLDAP Software is derived from the University of Michigan LDAP 3.3 Release.